ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (11,469)
  • Cell & Developmental Biology  (5,353)
  • Chemical Engineering  (4,234)
  • Fisheries
  • Industrial Chemistry
  • 2010-2014  (77)
  • 1995-1999  (5,950)
  • 1980-1984  (5,270)
  • 1925-1929
Collection
  • Articles  (11,469)
Years
Year
  • 1
    Publication Date: 2021-05-19
    Description: The genus Ctenochaetus is reportad in the waters of the Colombian Pacific based on two specimens of C. marginatus (Valenciennes) collected in 1993 at Gorgona Island (2°59' N, 78° 12' W). These specimens differ inseveral morphometric characteristics from thosepreviously examined. Such differences appear to be an artifact of the small number of specimens formerly examined and the consequent narrow ranges reportad. We suggest that temperature variability affects the distribution of C. marginatus in the tropical eastern Pacific.
    Description: El género es Ctenochaetus reportad en las aguas del Pacífico colombiano a partir de dos especímenes de C. marginatus (Valenciennes) recogidos en 1993 en la Isla Gorgona (2 ° 59 'N, 78 ° 12' W). Estos ejemplares difieren inseveral características morfométricas de thosepreviously examinados. Estas diferencias parecen ser un artefacto del pequeño número de muestras examinadas anteriormente y reportad los rangos estrechos consecuente. Sugerimos que la variabilidad de la temperatura afecta la distribución de marginatus C en el Pacífico tropical oriental.
    Description: Published
    Keywords: Fisheries ; Fisheries
    Repository Name: AquaDocs
    Type: Journal Contribution
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2021-05-19
    Description: Over the last decade eutrophication of freshwater artificial reservoirs in Cuba occurred in parallel to oligotrophication of estuarine and coastal waters. These two processes influenced both freshwater and marine fisheries. A dramatic shift in species composition in freshwater fisheries has occurred, from dominance by cichlids (tilapia) to dominance by cyprinids. The high fishery yield from some reservoirs, and shift in species composition, seems related to progressive eutrophication of reservoirs by nutrient subsidies from different anthropogenic activities; particular those related to the size of urban areas within their watersheds. On the other hand, marine landings of estuarine-dependent species declined more significantly than for other groups associated with seagrass beds–coral reefs and oceanic waters. The ratio between catches of estuarine-dependent species and those associated with seagrass beds and coral reefs, decreased significantly over the last 20 years. The decrease in landings was more evident in typical estuarine species, such as shrimps (Litopenaeus schmitti and Farfantopenaeus notialis), mangrove oyster (Crassostrea rhizophorae) and mullets (Mugil spp.). River damming increased during the same period and is significantly correlated with these decreases. It is hypothesized that two different processes acted synergistically, leading to dramatic decreases of several orders of magnitude, in the catches of estuarine species over the last decade: the trapping of nutrients and sediments by river damming, and a drastic reduction in nutrient inputs from land-based sources due to reduced fertilizer use. These are postulated to have affected not only estuarine resources, but also the whole coastal ecosystem.
    Description: Durante la última década, la eutrofización de los embalses artificiales de agua dulce en Cuba se produjo en paralelo a oligotrophication de estuarios y costeras aguas. Estos dos procesos de influencia de agua dulce y la pesca marina. Un cambio dramático en la composición de las especies en la pesca de agua dulce se ha producido, de la dominación de los cíclidos (tilapia) a la dominación de ciprínidos. La alta producción de la pesca de algunos embalses, y el cambio en las especies composición, parece relacionada con la progresiva eutrofización de los embalses de las subvenciones de nutrientes de diferentes actividades antropogénicas, especialmente las relacionado con el tamaño de las zonas urbanas dentro de sus cuencas. Por otro lado, los desembarques de especies marinas de estuario-dependientes disminuyeron significativamente más que para otros grupos asociados con algas marinas Los arrecifes de coral-camas y las aguas oceánicas. La relación entre las capturas de las especies que dependen de los estuarios y las asociadas a las praderas marinas y Los arrecifes de coral, se redujo significativamente en los últimos 20 años. La disminución en los desembarques fue más evidente en especies típicas de estuarios, tales como camarones (Litopenaeus schmitti y Farfantopenaeus notialis), ostra de mangle (Crassostrea rhizophorae) y la lisa (Mugil spp.). El represamiento del Río aumentó durante el mismo período y se correlaciona significativamente con estas disminuciones. Se planteó la hipótesis de que dos procesos diferentes actúan de forma sinérgica, que conduce a una disminución drástica de varios órdenes de magnitud, en las capturas de las especies de estuario en la última década: la captura de nutrientes y sedimentos por represas río, y una reducción drástica de los aportes de nutrientes de fuentes terrestres, debido a la reducción del uso de fertilizantes. Se postula que han afectado no sólo a los recursos estuarinos, sino también todo el ecosistema costero.
    Description: Published
    Description: ríos
    Description: impactos antropogénicos
    Keywords: river ; Fisheries ; Eutrophication
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed , Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2021-05-19
    Description: Se muestra la evolución de las capturas de las sierras y pintadas, se describen las 3 maneras en que las especies pueden quedar atrapadas en la redes de enmalles, así como también los tipos de redes (deriva, media agua y de fondo).
    Description: Published
    Description: Scomberomorus regalis
    Description: Scomberomorus maculatus
    Description: Scomberomorus cavalla
    Description: spanish mackerel
    Description: king mackerel
    Description: painted mackerel
    Description: enmalle
    Description: arte de pesca
    Keywords: Fisheries ; Artisanal fishing
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed , Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2021-05-19
    Description: Published
    Description: Mugil curema
    Description: Mugil liza
    Description: Mugil cephalus
    Description: Gerres cinereus
    Description: patao
    Description: coastal lagoons
    Keywords: Mullet fisheries ; Fisheries
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed , Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2021-05-19
    Description: Production of mangrove oyster (Crassostrea rhizophorae Guilding, 1828), north of Villa Clara, Cuba Province, tends to decline since 1980, accentuating from 2003 on. Despite regulations to protect the resource, minimum legal size and catch closures, the year 2008 presents the landing smaller volumes of the past 50 years. An analysis of the variability of catches in relation to natural and human factors, allows for precipitating causes of low productivity of this fishery resource; between the most representatives are expanding storage capacity of river water, salinity increment, the increase in frequency and intensity of hurricanes and the mismanagement of the extraction of oyster.
    Description: La producción de ostión de mangle (Crassostrea rhizophorae, Guilding, 1828), al norte de la provincia de Villa Clara, Cuba, tiende a la disminución desde de 1980, acentuándose a partir del año 2003. A pesar de regulaciones para la protección del recurso, talla mínima legal y vedas de captura, el año 2008 presenta los menores volúmenes de desembarque de los últimos 50 años. Un análisis de la variabilidad de las capturas, en relación con factores naturales y antrópicos, permite establecer causas desencadenantes de la baja productividad de este recurso pesquero; las más representativas son, la ampliación en la capacidad de embalse de aguas fluviales, aumentos de la salinidad, el incremento en la frecuencia e intensidad de los huracanes y un manejo inadecuado de la actividad extractiva de ostión.
    Description: Crassostrea rhizophorae, Cuba
    Keywords: Fisheries ; Environmental effects ; Fisheries
    Repository Name: AquaDocs
    Type: Preprint
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2021-05-19
    Description: Las capturas de langosta espinosa Panulirus argus (Latreille, 1804) en Cuba alcanzaron sus mayores volúmenes en la década de 1980 con un promedio anual de 11565 ton. En la década de 1990, la captura descendió a un promedio de 9327 ton, lo cual se ha visto agudizado entre 2000 y 2007 con un promedio de 6262 ton y una mayor variabilidad de las capturas, a pesar de un perfeccionamiento del sistema de manejo pesquero dado por: la disminución del esfuerzo pesquero y de la tasa de mortalidad por pesca desde 1999, el aumento del período de veda desde 2001 y el incremento gradual de la talla mínima legal de captura a partir de 2004. Los análisis más recientes sobre el estado de esta pesquería fueron presentados en el Quinto Taller Regional sobre la Evaluación y la Ordenación de la Langosta Común del Caribe en septiembre 2006 (Puga et al, 2006; FAO, 2007), donde se reconoció por la comunidad científica especializada que la pesquería de langosta cubana se encontraba bien manejada y plenamente explotada (no sobre- explotada) y se concluyó que además de la mortalidad por pesca, otros factores ajenos al sector pesquero estaban produciendo afectaciones en la abundancia del recurso, al causar daños al hábitat 1 en zonas de cría, influyendo negativamente por esta vía sobre el reclutamiento y la producción de langostas. Entre estos aspectos para Cuba se señalaron: la mayor frecuencia e intensidad de huracanes durante el último decenio, el desarrollo de las zonas costeras, la construcción de presas en las cuencas de captación de los ríos y de carreteras en el Archipiélago Sabana-Camagüey comunicando la isla principal con los cayos y los cayos entre si (pedraplenes).
    Description: Published
    Keywords: Fisheries ; Lobster fisheries ; Fisheries ; Environment management ; Recruitment ; Coastal zone management
    Repository Name: AquaDocs
    Type: Book Section
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2021-05-19
    Description: Se efectúa un estudio de la fauna acompañante del Mero, Epinephelus morio, en la pesquería con palangre de fondo del Banco de Campeche, México, durante el periodo 1987-2009. En la investigación se consideró información de 32 cruceros de investigación realizados en la etapa como parte del convenio pesquero firmado por Cuba y México para la evaluación sistemática del recurso. Se determinó la composición por especie y talla de las capturas, sus variaciones en la abundancia relativa, estructura de tallas, así como el índice de diversidad de Brillouin, la riqueza de especies (Margalef, 1980), la dominancia numérica y la constancia, estas ultimas valoradas según el esquema propuesto por Bodenheimer (1955). Se encontró que la fauna acompáñate de E. morio esta representada por 69 especies, agrupadas en 3 clases y 12 órdenes. De ellos, el orden mejor representado lo constituyó Perciformes con las familias Serranidae, Lutjanidae, Scombridae, Carangidae y Haemulidae como las más abundantes en número. Dentro de estas, dominaron las especies L. campechanus y O. chrysurus, apreciándose que las entidades mejor representadas son, L. campechanus (100%), O. chrysurus (96,87%) y M. bonaci (73,2%). Los largos medios observados se encontraron por encima de las tallas de primera maduración reportadas en la literatura. Sólo E. nigritus y L. analis presentaron individuos inmaduros. Se reportan tallas máximas superiores a las reportadas en la bibliografía en M. interstitiaslis (150cm), M. bonací (155cm) y E. nigritus (125cm). Se determinó que el rendimiento (cpue) y la diversidad de la fauna acompañante poseen una relación inversa con la disminución de la biomasa de mero. Por su parte, la diversidad y riqueza de especie presentaron sus mayores valores concordando con las temporadas de lluvias.
    Description: Mero Epinephelus morio, fauna acompañante, Banco de Campeche, México,
    Keywords: Fisheries ; Fauna ; Fisheries ; Fauna
    Repository Name: AquaDocs
    Type: Preprint
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2021-05-19
    Description: Se presentan los resultados de monitoreo de las poblaciones comerciales de cobo en el área comprendida entre los cayos El Cabezo y Boca de Sagua (220 49`N--230 04`N y los 790 35W—800 07´ `W), plataforma Norte de la Provincia de Villa Clara. A partir de los resultados de las densidades de individuos como índice de la abundancia y la estructura poblacional encontrada, se propone un potencial de captura de 104 TM (peso entero). Además, se definen las medidas de manejo para el uso sostenible del recurso Eustrombus gigas en esta zona. El aprovechamiento en carne desembarcada (Eviscerada y sin manto) para individuos adultos con talla comercial se obtiene por un factor de 0,074 (7,4%) del peso entero, que representa 7,7 TM. Se excluye el área protegida desde Las Picúas hasta Cayo Cristo.
    Description: cobo (Eustrombus gigas), Caibarién, Villa Clara
    Keywords: Monitoring ; Fisheries management ; Fisheries
    Repository Name: AquaDocs
    Type: Preprint
    Format: 4
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2021-05-19
    Description: La Commission Sous Régionale des Pêches (CSRP), qui est un organisme intergouvernemental de coopération halieutique dont l’objectif global est l’harmonisation à long terme, des politiques des pays membres en matière de préservation, de conservation et d'exploitation durable de leurs ressources halieutiques et le renforcement de leur coopération au profit du bien-être de leurs populations respectives, a obtenu par l’intermédiaire de la Banque mondiale, un Don du Fonds pour l’Environnement Mondial (FEM) et du Gouvernement du Japon, pour la préparation d’un Projet Régional des Pêches en Afrique de l’Ouest (PRAO) pour trouver une solution à la problématique susvisée. Ce projet implique 9 pays côtiers: la Mauritanie, le Cap Vert, le Sénégal, la Gambie, la Guinée Bissau, la Guinée, le Sierra Léone (Etats membres de la CSRP), ainsi que le Libéria et le Ghana. Le PRAO comprend trois composantes : (1) Bonne Gouvernance et Gestion Durable des Pêches ; (2) Réduction de la Pêche Illicite ; (3) Augmentation de la Contribution des Ressources Halieutiques dans les Economies Locales (incluant la réalisation d’infrastructures et équipements dans les pêcheries). Certes, les activités prévues dans le cadre du PRAO sont pressenties pour contribuer au développement du secteur de la pêche dans les pays ciblés et apporter des bénéfices aux populations locales. Toutefois, elles pourraient engendrer dans certains cas des effets négatifs aux niveaux environnemental et social (notamment celles prévues dans la composante 3), si des mesures adéquates ne sont pas prises au préalable. Afin de minimiser ces effets défavorables, il a été requis l’élaboration de la présente Evaluation Environnementale et Sociale (EES).
    Description: Commission Sous Régionale des Pêches (CSRP)
    Description: Published
    Description: ressource marine, ressource côtière, politique de pêhce, environnement, qualité des produits, pollution, gestion des pêches,aire marine protégée
    Keywords: Marine resources ; Fisheries ; Fishery management ; Coastal fisheries ; Quality assurance ; Environment management ; Marine resources ; Fisheries ; Fishery management ; Coastal fisheries ; Coastal zone ; Fishery regulations ; Fishery economics ; Marine pollution ; Quality control ; Illegal fishing ; Fishery organizations ; Quality assurance
    Repository Name: AquaDocs
    Type: Report
    Format: 111
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2021-05-19
    Description: Ce travail représente une contribution à l'étude de l'activité de pêche hauturière dans le gouvernorat de Médenine, particulièrement, au niveau du port de Zarzis ; durant la période (juin 2005-juin 2006). Il consiste à réaliser, grâce à des enquêtes menées au port, deux types d'analyses : une analyse quantitative afin de déterminer les débarquements saisonniers moyens des espèces les plus débarquées par la pêche hauturière et une analyse qualitative pour établir les structures démographiques des espèces les plus exploitées dans la région. Les résultats obtenus ont montré que, durant la période d'étude, les principales espèces débarquées par la pêche hauturière sont la sardinelle, le maquereau, le saurel, le rouget blanc, le pageot, la thonine, la seiche et la crevette royale. En examinant les débarquements saisonniers moyens des espèces les plus débarquées par type de pêche, nous avons remarqué que deux ou trois espèces dominent pour chaque saison. De plus, l'analyse des structures démographique des apports a montré que la majorité des individus débarqués sont matures, à l’exception du maquereau dont les captures sont constituées d’individus immatures, surtout pendant les saisons d’été et d’automne.
    Description: This work represents a contribution to the study of the offshore fishing activity in the governorate of Medenine, particularly at the port of Zarzis, during the period (june 2005-june 2006. It is to realize, through surveys conducted at the port, two types of analyzes: a quantitative analysis to determine the average seasonal landings of most landed species by fishing offshore units and qualitative analysis to determine the demographic structure of the most exploited species in the region. The obtained results showed that during the period of study, the main landed species by offshore fishing are sardinella, mackerel, horse mackerel, white mullet, sea bream, skipjack tuna, cuttlefish and the caramote prawn. By examining the average seasonal landings of the most landed species, we noticed that, for each season, two or three species dominate. Furthermore, analysis of demographic structures of the landings showed that the majority of landed individuals are mature, with the exception of mackerel catches which are composed of immature individuals, especially during the seasons of summer and autumn.
    Description: Published
    Description: analyse qualitative
    Description: pêche hauturière
    Keywords: Quality analysis ; Offshore ; Fisheries
    Repository Name: AquaDocs
    Type: Proceedings Paper , Refereed , Meeting abstract
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    Publication Date: 2021-05-19
    Description: El presente artículo da una descripción detallada de la elaboración y del "curado" de cuerdas de curricán, utilizadas anteriormente para la pesca en Taganga, un pueblo pescador en la costa norte de Colombia. Antes del "curado", estas cuerdas de fibras de algodón y de fabricación industrial, eran o destorcidas o torcidas a mano nuevamente, o tensionadas y envueltas con una cuerda más delgada del mismo material. El "curado" que siguió a estas operaciones se efectuó tanto en una cocción de corteza de las raíces zanconas de mangle, y/o por medio de un frote de estas cuerdas con los hypocotylos del mismo árbol (Rhizophora manglr). Por medio de las técnicas aquí descritas, los pescadores aspiraban a aumentar la resistencia de sus aparejos de pesca en el agua de mar.
    Description: The present paper gives a detailed description of the elaboration and curing of curricán Unes, formerly used as fishing lines in Taganga, a small fishing village on the northem coast of Colombia. These lines, made of cotton fibers and produced industrially, were disassembled and then retwisted by hand, or tightened and then carefully covered with a thinner string of the same material. The curing {"curado") that followed these operations was achieved by immersion of the lines into a boiled infusión of the bark of the prop roots of mangroves (Rhizophora mangle) and/or a rinsing with the hypocotyls of the same trees. By means of the techniques mentioned, the fishermen sought to improve the resistance of their fishing gear to sea water.
    Description: Published
    Keywords: Fisheries ; Fishing ; Gear construction ; Fisheries ; Fishing
    Repository Name: AquaDocs
    Type: Journal Contribution
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    Publication Date: 2021-05-19
    Description: During a 3 week study, a total of 55 individuals of the redlip blenny (Ophioblennius atlanticus) were observed for at least two 15-minute periods, and several for ten of such periods. The sizes of their territories were estimated, the color pattern of each specimen an intra and interspecific interactions were recorded. The mean territory size of the redlip blenny in the study area appeared to be greater than that of these blennies studied in Curacao and Barbados by NURSALL (1977), the difference reflecting perhaps different methods of identifying the territories or a lower density of O. atlanticus in the Santa Marta área. Territories did not appear to be as consistently defended at the study area as at Barbados/Curacao and our impression ¡s that individuals holding large territories are less likely to defend their borders. It seems possible that light colored individuals are protected by their coloration from attack by dark colored territory owners. In territorial defense the redlip blennies grabbed each other tighthy by the mouth and struggled in this position repeatedly for about 15 seconds. Interspecific antagonism was common in the present study, the redlip blennics defended their territory frequently against Eupomacentrus dorsopunicans or E. partitus.
    Description: Durante un estudio de tres semanas, un total de 5 i individuos del bií'nido Ojih'toblcnnius atlnniicur. fueron observados por lo menos durante dos períodos de 1 í minutos para cada individuo y en algunos casos hasta por 10 de estos periodos. Se estimó el área de sus respectivos territorios y se tomó notí de los patrones de coloración de cada espécimen y de las relaciones intra e interespecificas de ellos. El tamaño promedio del territorio de estos blénidos resultó ser mayor que el de los respectivos territorios estudiados por NURSALL (1977) en Curacao y Barbados. Esta diferencia posiblemente se debe a un método diferente de definir los territorios o refleja una densidad menor de la población de O. aílanticus en Santa Marta, Los territorios del área fueron defendidos con menor intensidad a como lo fueron los de Barbados/ Curacao y es nuestra impresión que individuos ocupando un territorio extenso tienden a defender sus límites en menor grado. El color claro de algunos individuos probablemente los protege de agresiones por parte de individuos de color oscuro. En el acto de defensa territorial intraespecífica, los blénidos se agarran por sus bocas y se sacuden mutuamente durante aproximadamente 15 segundos , pudiéndose repetir esti varias veces. Con frecuencia se observarondefensas de los territorios dirigidas hacia los peces doncella Eupomacentrus dorsopunicnas y E. partitus.
    Description: Published
    Keywords: Fisheries ; Biology ; Fisheries ; Biology
    Repository Name: AquaDocs
    Type: Journal Contribution
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    Publication Date: 2021-05-19
    Description: Se registra por primera vez el fenómeno de albinismo en la familia de peces Muraenesocidae, con base en dos ejemplares de Cynoponticits savanna capturados en la Península de la Guajira. Caribe colombiano.
    Description: The phenomenom of albinism is reported for the first time in che fish family Muraenesocidae. Two anomalous individuals of Cynoponticus savanna were collected from the Guajira Península colombian Caribbean.
    Description: Published
    Keywords: Fisheries ; Albinism ; Fisheries ; Albinism ; New records
    Repository Name: AquaDocs
    Type: Journal Contribution
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    Publication Date: 2021-05-19
    Description: Se muestran las capturas históricas de la biajaiba (1935-2000), la evolución de las capturas del pargo (una de las especies de mayor interés económico en Cuba). Se evalúa la utilización de éstas artes de pesca en especies comerciales y su implicación con daños al medio ambiente. Se tiene en cuenta que los pargos criollos, la biajaiba y el caballerote representan el 20 % de las capturas.
    Description: Published
    Description: pesquería artesanal
    Description: cubera
    Description: cherna criolla
    Description: pesca del alto
    Description: pargo
    Description: rabirrubia
    Description: caballerote
    Description: biajaiba
    Keywords: Fisheries ; Artisanal fishing
    Repository Name: AquaDocs
    Type: Journal Contribution , Non-Refereed , Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    Publication Date: 2021-05-19
    Description: Se ha estudiado la variación anual de la condición de la lisa Mugil incilis Hancock en la Ciénaga Grande de Santa Marta (CGSM), la mayor laguna costera del Caribe Colombiano, haciendo énfasis en la influencia ejercida por factores ambientales como la salinidad, la temperatura y la transparencia de las aguas sobre la condición de esta especie de Mugilidae. Las diferencias estacionales observadas en la condición de M. incilis están evidentemente relacionadas con su desarrollo gonadal y dependen de la disponibilidad de alimento. La dieta de M. incilis se basa en detritos y su suministro de alimento parece ser muy afectado por el aporte fluvial a la CGSM, el cual es también responsable de los cambios en la salinidad de la laguna, esto explica la relación inversa (r = -0.82) hallada entre la salinidad y la condición de M. incilis expresada por C = 0.9949 - 0.0057 S(°/oo). La variación anual de la salinidad sigue un patrón rítmico de cambios estacionales, no precisamente "in situ", sino en regiones continentales distantes: las cabeceras de los tributarios de la CGSM. Estas lisas desovan en aguas del Caribe adyacente a la CGSM y su período de migración (dic-marzo) comienza con su mejor condición física, y retornan a sus áreas de alimentación en la CGSM 2 a 4 semanas después, hasta el final de la migración, con su condición mínima ya que al parecer estas lisas no se alimentan durante su migración de desove. No se observaron cambios relacionados con las variaciones de la temperatura. Las aguas más turbias coincidieron con los sitios de alimentación de M. incilis.
    Description: The annual variation in condition of the mullet Mugil incilis Hancock has been studied in the Ciénaga Grande de Santa Marta (CGSM). The largest coastal lagoon on the Colombian Caribbean, with emphasis on the influence of such environmental factors as salinity, temperature and transparence of the waters on the condition of this species of Mugilidae. Seasonal differences observed in condition of M. incilis are evidently related to gonadal development and depend on food availability. The diet of M, incilis is based on detritus and its food supply seems to be very influenced by river discharge which also accounts for the salinity changes in the lagoon. this explains the in verse correlation (r = -0.82) found between salinity and condition of the mullets expressed as C = 0.9949 - 0.0057 S (°/oo). Annual salinity variation follows a rhythmic pattern of seasonal changes. not precisely "in situ", but in distant continental regions: the headwaters of the tributarles of the CGSM. These mullets spawn in Caribbean waters adjacent to the CGSM and their migración period (Dec-March) begins with their best physical condición, returning to their feeding áreas in the CGSM 2 or 4 weeks lacer, until the end of the migración, with their lowest condition since these mullets apparently do not feed at all during the spawning migration. No change related to temperature variations was observed. and turbid waters were the rule in M. incilis feeding sites.
    Description: Published
    Description: Mugil incilis
    Keywords: Fisheries ; Estuaries ; Ecology ; Coastal lagoons ; Fishery biology ; Fisheries ; Coastal lagoons ; Estuaries ; Fishery biology ; Ecology
    Repository Name: AquaDocs
    Type: Journal Contribution
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    Publication Date: 2021-05-19
    Description: Un análisis de los datos arqueológicos e históricos sobre la pesca en Cuba muestra que el impacto de la población aborigen sobre los recursos pesqueros no fue significativo debido a su baja densidad poblacional y a las tecnologías de pesca. El interés por el oro, el tamaño de la población, las limitaciones tecnológicas para la pesca y preservación de las capturas así como las preferencias dietéticas de los españoles todas indican que la pesca tampoco fue una actividad económica importante durante los tres siglos que siguieron a la llegada de Colón. Las preferencias por la carne de res y el bacalao salado y la baja tasa de crecimiento poblacional durante el período colonial determinaron que la mayor parte de los recursos pesqueros, con la excepción del manatí y las tortugas marinas, permanecieran prácticamente inexplorados durante varios siglos después de la Conquista. Los datos estadísticos e históricos revelan que la pesca experimentó un rápido crecimiento desde 1950 y este patrón parece ser una característica común en el Caribe así como en otras partes del mundo. Las presiones sobre la vida marina fueron más evidentes en la segunda mitad del siglo xx cuando el crecimiento poblacional, las mejoras tecnológicas y las demandas del mercado aceleraron el sector pesquero así como la urbanización en la mayoría de los países del caribe.
    Description: Published
    Keywords: Integrated management ; Fisheries
    Repository Name: AquaDocs
    Type: Proceedings Paper , Refereed , Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    Publication Date: 2021-05-19
    Description: Se describen y se ilustran seis especies de parásitos pertenecientes a la familia Acanthocolpidae encontradas en 19 especies de peces en su mayoría de considerable importancia económica. El estudio taxonómico de estos parásitos se realizó en la Ciénaga Grande de Santa Marta, al norte de Colombia, desde Enero de 1978 hasta Junio de 1979.
    Description: A taxonomic study for parasites found in 19 mostly economically important fish species was carried out in ihe Ciénaga Grande de Santa Marta (Northern Colombia) from January 1978 uritil June 1979. Six species of fish parasites belonging to the family Acanthocolpidae are described and illustrated herein.
    Description: Published
    Keywords: Fisheries ; Ecology ; Parasites ; Parasites ; Fisheries ; Ecology
    Repository Name: AquaDocs
    Type: Journal Contribution
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    Publication Date: 2021-05-19
    Description: En 1987, se inicia un programa de muestreos biológicos del calamar argentino ///ex argentinas a bordo de barcos comerciales de la flota cubana de pesca que operan en la plataforma patagónica. La talla de los organismos para ambos sexos presenta un comportamiento estratificado por profundidades, los ejemplares de mayor tamaño se encuentran a profundidades superiores y viceversa, lo cual se ajusta a una recta de regresión (r2 = 0.88; a = 0.05). Las hembras alcanzaron largos promedio del manto superior a los machos, incrementándose la presencia de machos en las capturas desde enero a abril. Se estimaron los largos promedio de primera maduración, como 20.5 y 26.5 cm de largo del manto para machos y hembras respectivamente. Se observó un aumento de la proporción de individuos maduros de febrero a abril, haciéndose más marcado este fenómeno en los machos, que en su mayoría presentaban abundantes espermatóforos en el saco. Se obtuvo la relación largo-peso para hembras y machos y para la combinación de ambos sexos.
    Description: In 1987 a program for the biological sampling of squid ///ex argentinas, was begun on board of a fishing ship belonging to the Cuban Fisheries-Fleet, wich operates in the Patagonian Shelf. The lengths of both sexes presented a estratified pattern with individuals of larger size found in higher depths and viceversa; this pattern is adjusted to a regression line (r2 = 0.88; a = 0.05). Pernales reached average length larger (han males and the rate of males in catches increased from january to april. The first maturation average length was estimated about 20.5 cm for males and 26.5 cm for females. An increase of the rate of mature individuals was observed between february and april emphazasing ¡n males which showed abundant espermatophores in the sac.
    Description: Published
    Description: squid, Flota Cubana
    Keywords: Fisheries ; Squid culture ; Biological charts ; Biological data ; Fisheries ; Squid culture
    Repository Name: AquaDocs
    Type: Journal Contribution
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    Publication Date: 2021-05-19
    Description: A yield per recruit model has been used to compare the effects of mesh size increment on the yields and revenues of the fisheries of Cameroon under two different cases. Case 1 assumes the commercial fishery to move from the exploitation of three age-groups to two age-groups with no interactions with the artisanal fishery, whereas Case 2 takes into account these interactions. The difference in the percentage increase of yield per recruit between case 1 and case 2 is 61% at current fishing (46% and 18% yield per recruit increment in cases 1 and 2 respectively). The usually accepted long-term yield per recruit increment with increase of age at first capture (with a single non-interacting fisheries) is, in this case, cancelled out. However, the revenues increase by 72% and 63% in cases 1 and 2 respectively. Therefore the economic approach, compared with purely biological analyses, is more convincing. In general, as fisheries always interact, a single-fishery management approach should not be the rule as it is at present; management strategies should consider interactions between different fisheries and be based on their economic performances and not, as said earlier, on purely biological considerations. This is because a biological approach to fisheries management will, at best, be modified by economic factors, or, at worst, be ignored totally in favour of economic policies.
    Description: Published
    Keywords: Biology ; Fisheries ; Biological interaction ; Sciaenidae ; Fisheries development ; Fishery management ; Yield/recruit ; Commercial fisheries ; Artisanal fishing
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed , Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    Publication Date: 2021-05-19
    Description: La pêche au Sénégal joue un rôle économique et social très important par une contribution globale de près de 11% du PIB primaire et 2,3% du PIB total. Elle occupe de façon directe et indirecte environ 600 000 personnes, soit près de 17% de la population active selon la DP M. Cependant ces dernières décennies, les études ont montré que le secteur traverse une crise aiguë se traduisant par une raréfaction croissante des ressources, notamment les espèces nobles qui ont une forte valeur commerciale. Cette crise est due entre autres à une surexploitation de ces ressources qui est le résultat d’un manque de maîtrise de l’effort de pêche surtout pour les pêcheries artisanales (80% des débarquements et plus de 60% des approvisionnements des industries de la place) au regard du volume de ressources disponibles. Ce manque de maîtrise est dû essentiellement par un défaut du suivi contrôle et surveillance au niveau de la pêche artisanale par l’Etat, qui n’a pas les moyens humains et matériels pour appliquer des mesures de gestion, qui pour la plupart ne sont pas adaptées aux réalités des acteurs à la base. L’objet de cette étude est d’analyser une nouvelle approche axée sur la surveillance participative basée sur l’émergence d’initiatives locales de cogestion au niveau des quatre (04) sites du programme GIRMaC que sont ; Ouakam, Ngaparou, Foundiougne et Bétenty. Il ressort de cette étude que : • Le secteur de la pêche traverse une crise aiguë due principalement selon les acteurs à un défaut de suivi, contrôle et surveillance tel que appliqué actuellement ; • L’approche de cogestion avec des bases juridiques cohérentes, comme le propose le programme GIRMaC peut être un moyen viable pour solutionner à la crise que traverse la pêche ; • D’une part le système Suivi Contrôle et Surveillance coûte cher, d’autre part que ces coûts sont fortement amoindris lorsque les acteurs participent à l’effort de surveillance, par une démarche de surveillance participative en cogestion.
    Description: Président : Omar Thiom THIAW, Professeur UCAD Membres : • Niokhor DIOUF, Chercheur IUPA. • Luis Tito Morais, Chercheur IRD Dakar. • Djiby THIAM, Chercheur GIRMac
    Description: Published
    Description: surveillance; contrôle; cogestion; effort de pêche; pêcherie; surexploitation; biodiversité; pêche artisanale
    Keywords: Ocean surveillance ; Ecosystem management ; Fishing effort ; Overexploitation ; Biodiversity ; Artisanal fishing ; Fisheries
    Repository Name: AquaDocs
    Type: Theses and Dissertations , Master thesis
    Format: 87
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    Publication Date: 2021-01-30
    Description: The first meeting of the South West Indian Ocean EAF Regional Task Group (RTG) was held in Mombasa, Kenya, from 27 to 30 January 2009, together with an ecological risk assessment methodology workshop. It was attended by 20 partic ipants from the South West Indian Ocean (SWIO) countries, the South West Indian Ocean Fisheries Project (SWIOFP), the Agulhas and Somali Currents Large Marine Ecosystems (ASCLME) project, the Scientific Committee of the South West Indian Ocean Fisheries Commission, the United Nations Environment Programme (UNEP)/Nairobi Convention Implementation Unit, the African Union Commission and FAO. The RTG is an implementation structure under the EAF-Nansen project GCP/INT/003/NOR and serves as the forum for training in ecological risk assessment that is the methodology used for the identification and prioritization of issues requiring management attention. The main objectives of the meeting and workshop we re to discuss and facilitate key processes and activities for the implementation of the ecosystem approach to fisheries management in the South West Indian Ocean region including the modalities for the formation and functioning of the RTG and National Task Groups (NTGs). It was explained that, to be able to achieve the objectives of implementing an ecosystem approach to fisheries at the national level, certain key structures have to be in place including the NTG with representatives of key stakeholders in a given fishery and that would take the lead in the process. An overview of the key concepts and process of the ecological risk assessment methodology were clarified. Participants were also introduced to the preparation of EAF baseline reports to be used as initial input for the work on ecosystems approach to fisheries. It was explained that the preparation of the report is to be led by national and regional experts and overseen by the NTG. For the exercises the participants worked in three subgroups formed during the meeting with each group selecting a chairman who moderate d the discussions and a rapporteur. The participants expressed satisfaction with the development of a communication strategy for the project and especially with the participatory approach used.
    Description: FAO, NORAD, Institute of Marine Research
    Description: Published
    Description: National task groups
    Description: Regional task groups
    Description: Ecosystem Approach to Fisheries
    Keywords: Ecosystems ; Fisheries ; Ecosystems ; Fishery resources ; Fisheries management
    Repository Name: AquaDocs
    Type: Report , Non-Refereed
    Format: 36
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    Publication Date: 2021-05-19
    Description: Published
    Description: espéces pélagiques
    Description: sardine
    Description: pêche industrielle
    Keywords: Fisheries ; Pelagic fisheries ; Industrial fish ; Fish products ; Fishing industry ; Fishing fleet
    Repository Name: AquaDocs
    Type: Journal Contribution , Non-Refereed , Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    facet.materialart.
    Unknown
    Nigerian Institute for Oceanography and Marine Research | Lagos, Nigeria
    Publication Date: 2021-01-30
    Description: Published
    Description: Fisheries newsletter
    Keywords: Fisheries ; Marine sciences ; Fisheries literature
    Repository Name: AquaDocs
    Type: Report , Non-Refereed
    Format: 30pp.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    facet.materialart.
    Unknown
    Nigerian Institute for Oceanography and Marine Research | Lagos, Nigeria
    Publication Date: 2021-01-30
    Description: Published
    Description: Fisheries newsletter
    Keywords: Fisheries ; Marine sciences ; Fisheries literature
    Repository Name: AquaDocs
    Type: Report , Non-Refereed
    Format: 34pp.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    facet.materialart.
    Unknown
    Nigerian Institute for Oceanography and Marine Research | Lagos, Nigeria,
    Publication Date: 2021-01-30
    Description: Published
    Description: Fisheries newsletter
    Keywords: Fisheries ; Fisheries literature
    Repository Name: AquaDocs
    Type: Report , Non-Refereed
    Format: 11pp.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    Publication Date: 2021-05-19
    Description: Unpublished
    Description: conservation
    Description: chaine froide
    Description: poisson
    Keywords: Food conservation ; Fisheries ; Fish conversion ; Conservation (fishery products) ; Glass ; Fisheries
    Repository Name: AquaDocs
    Type: Journal Contribution , Non-Refereed , Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    Publication Date: 2021-05-19
    Description: Published
    Description: Pêche
    Description: Senneur
    Keywords: Seining ; Fisheries ; Fisheries ; Seiners
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed , Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    Publication Date: 2021-05-19
    Description: ACDI;CRDI; République Française, Ministère des Affaires Etrangéres; CDE; Enda Graf Sahel;
    Description: Conseil Info MPEA, Projer d'Accés à l'information et au Conseil pour les microet petites entreprises agroalimentaires; Projet d'Appui aux Opérateurs/trices de l'Agroalimentaires (PAOA); Cintech Agroalimentaire; Groupe de Recherche et d'Echanges Technologiques (GRET); Enda GRaf Sahel; SNC-LAVALIN International
    Description: Published
    Description: transformation; transformation artisanale; échantillonage; collecte de données; commercialisation
    Keywords: Processing fishery products ; Biological sampling ; Data collections ; Marketing and distribution ; Fisheries
    Repository Name: AquaDocs
    Type: Theses and Dissertations , Master thesis
    Format: 41
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    Publication Date: 2021-05-19
    Description: Français - Les traits essentiels de la côte sénégalaise, repères historiques de la pêche, communautés de pêcheurs, caractéristiques des flottes et modes d’accès à la ressource et d’interaction sont analysés. Les caractéristiques, tendances décroissantes de l’abondance,niveaux d’exploitation, mesures d’aménagement, relations interspécifiques, changements potentiels et sources de variation des stocks démersaux côtiers sont précisés. Les notions de tactiques et stratégies de pêche sont passées en revue, conceptualisées puis étudiées.Le modèle «Dynamique Conjointe Exploitation Ressource» utilisé repose sur la définition de 4 typologies. L’utilisation de méthodes de classification et de connaissances d’experts conduit à considérer 32 stocks, 31 strates, 82 tactiques et 25 flottilles artisanales et chalutières. Les typologies sont articulées avec la prise en compte de paramètres relatifs à l’économie, aux stocks, flottilles et règles de décisions. L’ajustement est satisfaisant en partie. Toutefois, le modèle garde son importance en matière de prospective et d’objectifs à atteindre via la définition de variables de contrôle. Notre travail peut être considéré comme une esquisse invitant à un groupe de travail élargi aux experts des institutions halieutiques nationales voire, sous-régionales. Des propositions sont faites sur les bases de données, les licences de pêche et l’étude des tactiques et stratégies à mener suivant des pas de temps raisonnables pour tenir compte du grand dynamisme des pêcheries. Dès lors qu'il s’agit de caractériser l'impact de la pêche sur l'écosystème, ces travaux sont des éléments essentiels des recherches à faire sur la dynamique des écosystèmes exploités. English - The essential features of the Senegalese coast, fisheries history, fishermen's communities, artisanal and trawling fleet’s characteristics and their way of accessing to the resource and interactions are described. The characteristics, evolutionary tendencies of abundance, level of exploitation, measures of fisheries management, interspecific relationship, potential evolutionary changes and sources of variation of coastal demersal stocks are specified. Tactics and strategies are reviewed, conceptualized and studied. We used the model "Dynamique Conjointe Exploitation Ressource" which lies on 32 stocks, 31 strata, 82 tactics, 25 fleets and several other parameters dealing with stocks, fleets, economy and making decision rules. The adjustment is partially satisfactory but the model is of great interest for prospective studies and objectives to reach once defined variables of control. Our work is an outline calling for an enlarged working group implying national or sub regional fisheries institutional experts. Tactics and strategies studies, re-actualized in artisanal fisheries, are performed for the first time in industrial fisheries. The typological approach is simple, pertinent, efficacy and fast. Propositions are made relatively to databases, fishing licenses and tactics and strategies studies that should be implemented according to a reasonable time steps in order to take into account the big dynamism of the Senegalese fisheries. As it is intended to characterize fisheries impact on ecosystem, these works are one of essential research elements on the dynamic of exploited ecosystems.
    Description: Published
    Description: pêcherie; démersale côtière; modélisation; stocks; écosystème; communauté de pêcheurs; eaux continentales; eaux marines; saison hydrologique; pêcheur; flottille; crevettier; capture; aménagement des pêcheries; pêche chalutière; pêche artisanale; licence de pêche; permis de pêche
    Keywords: Fisheries ; Demersal fisheries ; Modelling ; Stocks ; Ecosystems ; Community fishing ; Inland waters ; Marine water ; Hydrologic cycle ; Fishermen ; Fishing fleet ; Shrimp fisheries ; Capture fisheries ; Fisheries management ; Trawling ; Artisanal fishing ; Fishing licenses
    Repository Name: AquaDocs
    Type: Theses and Dissertations , Bachelor thesis
    Format: 234
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    Publication Date: 2021-05-19
    Description: Agriculture, Nature and Food Quality, Den Haag (Netherlands); Ministerie Van Buitenlandse Zaken, Brussel (Belgium); Wageningen International, Wageningen (Netherlands)
    Description: Projet BBI 13286 : Pêche durable des petits pélagiques en Afrique Nord Ouest Ce rapport a été préparé avec le soutien financier de la Coopération néerlandaise (DGIS) dans le cadre de son Programme de politique internationale en matière de biodiversité (BBI).
    Description: Published
    Description: pêche traditionnelle; taille; échantillonnage; écosystème; upwelling; biomasse; filet maillant dérivant; senne tournante; senne moustiquaire; senne de plage; maquereau; chinchard; sardinelle; ethmalose; reproduction; courant; stocks; réglementation; pêche par espéce; engin de pêche; pélagique; zone côtière; pirogue; pêche artisanale; pêcheur
    Keywords: Biomass ; Ecosystems ; Fisheries ; Fishermen ; Stocks ; Ocean currents ; Winds ; Size ; Fishing effort ; Pelagic fisheries ; Sexual reproduction ; Multispecies fisheries ; Fisheries ; Artisanal fishing ; Fishermen ; Fishing effort ; Canoe fisheries ; Coastal zone ; Fishery engineering ; Protected resources ; Pelagic fisheries ; Cycles ; Sexual reproduction ; Multispecies fisheries ; Stocks ; Ocean currents ; Winds ; Biomass ; Upwelling ; Ecosystems ; Maritime legislation ; Size
    Repository Name: AquaDocs
    Type: Report
    Format: 53
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    Publication Date: 2021-05-19
    Description: Published
    Description: conservation
    Description: produits
    Description: pêche
    Keywords: Conservation ; Fisheries ; Fish products
    Repository Name: AquaDocs
    Type: Journal Contribution , Non-Refereed , Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    facet.materialart.
    Unknown
    Nigerian Institute for Oceanography and Marine Research, | Lagos, Nigeria,
    Publication Date: 2021-01-30
    Description: Published
    Description: Fisheries newsletter
    Keywords: Fisheries ; Fisheries literature
    Repository Name: AquaDocs
    Type: Report , Non-Refereed
    Format: 8pp.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    Publication Date: 2021-01-30
    Description: En Afrique de l'Ouest, la zone littorale et ses ressources représentent une composante essentielle pour le développement. Près de 60% de la population est concentrée à moins de 20 km des côtes . La part des ressources halieutiques dans l'alimentation des populations est très importante et croissante. Au Sénégal par exemple, elles contribuent jusqu'à 70% des apports en protéines. A cela s'ajoute le poids socio-économique très important de la pêche en général et de la pêche artisanale en particulier devenue l'un des secteurs les plus stratégiques pour l'économie nationale en Mauritanie notamment. Le Cadre Stratégique de Lutte contre la Pauvreté du Gouvernement Mauritanien considère que : "compte tenu des possibilités qu'elle offre en terme de création d'emplois et de sécurité alimentaire notamment pour les populations pauvres, mais également de génération de recettes en devises, la pêche artisanale revêt une grande priorité, un plan décennal de développement lui sera consacré ".
    Description: Published
    Description: pêche artisanale; littoral; carpe; ethmalose; donnée; mulet; pélagique; pourtague; stock halieutique; pêche; communauté de pêcheurs; effort de pêche; PNBA; technique de pêche; senne tournante; sardinelle; gonade; filet de pêche; courbine; migration d'espèces; campagne de pêche; écosystème; dégradation d'habitats de poissons; enjeux socioéconomiques; commercialisation; conservation
    Keywords: Fisheries ; Fishermen ; Stocks ; Fish fillets ; Ecosystems ; Fishing effort ; Pelagic fisheries ; Artisanal fishing ; Fisheries ; Fishermen ; Stocks ; Capture fishery economics ; Fish eggs ; Fish fillets ; Fishing effort ; Fishery technology ; Mullet fisheries ; Pelagic fisheries ; Ecosystems
    Repository Name: AquaDocs
    Type: Report
    Format: 6
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    Publication Date: 2022-05-25
    Description: Author Posting. © The Author(s), 2012. This is the author's version of the work. It is posted here by permission of Taylor & Francis for personal use, not for redistribution. The definitive version was published in Aquaculture Economics & Management 16 (2012): 167-181, doi:10.1080/13657305.2012.678551.
    Description: This study presents a framework for analyzing the interactions between aquaculture and capture fisheries in the context of ecosystem-based management. We extend a model of the economic and ecological systems in coastal New England by incorporating an aquaculture sector in a computable general equilibrium (CGE) model and by examining the forage fish and aquaculture link in a marine food web. We show that aquaculture and commercial fisheries interact in a complex way throughout the economic and ecological systems.
    Description: This work was supported by the NOAA Saltonstall-Kennedy Grant Program (Award No. NA09NMF4270097), the MIT Sea Grant College Program (NOAA Award No. NA10OAR4170086, Subaward No. 5710002974), and the Johnson Endowment of the WHOI Marine Policy Center.
    Description: 2013-06-08
    Keywords: Aquaculture ; Fisheries ; Ecosystem-based management ; CGE model ; Food web model ; Forage fish
    Repository Name: Woods Hole Open Access Server
    Type: Preprint
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    Publication Date: 2022-05-25
    Description: Author Posting. © Ecological Society of America, 2013. This article is posted here by permission of Ecological Society of America for personal use, not for redistribution. The definitive version was published in Ecological Applications 23 (2013): 959–971, doi:10.1890/12-0447.1.
    Description: The biological benefits of marine reserves have garnered favor in the conservation community, but “no-take” reserve implementation is complicated by the economic interests of fishery stakeholders. There are now a number of studies examining the conditions under which marine reserves can provide both economic and ecological benefits. A potentially important reality of fishing that these studies overlook is that fishing can damage the habitat of the target stock. Here, we construct an equilibrium bioeconomic model that incorporates this habitat damage and show that the designation of marine reserves, coupled with the implementation of a tax on fishing effort, becomes both biologically and economically favorable as habitat sensitivity increases. We also study the effects of varied degrees of spatial control on fisheries management. Together, our results provide further evidence for the potential monetary and biological value of spatial management, and the possibility of a mutually beneficial resolution to the fisherman–conservationist marine reserve designation dilemma.
    Description: M. G. Neubert acknowledges the support of the National Science Foundation (DMS-0532378, OCE-1031256) and a Thomas B. Wheeler Award for Ocean Science and Society. H. V. Moeller acknowledges support from a National Science Foundation Graduate Research Fellowship. This research is based in part on work supported by Award No. USA 00002 made by King Abdullah University of Science and Technology (KAUST).
    Keywords: Bioeconomics ; Destructive fishing practices ; Fisheries ; Habitat damage ; Marine protected areas ; Marine reserves ; Optimal control ; Optimal harvesting ; Spatial management
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    facet.materialart.
    Unknown
    Ministerio de Medio Ambiente y Medio Rural y Marino | Madrid (Espagne)
    Publication Date: 2021-05-19
    Description: Description du secteur de la pêche Avec la Mauritanie, le Sénégal est de loin le plus grand producteur de produits de pêche de la sous région. Avec 718 km de cote et un territoire maritime de 198km2, 15 745 km2 de superficie fluviale, 2 estuaires, des mangroves et un lac de 350km2, le Sénégal possède tous les atouts des plus grands producteurs de pêche. Le potentiel annuel de captures s’élève à 500 000 tonnes. Le secteur a subi une croissance spectaculaire ces trente dernières années : les débarquements sont passés 50 000 tonnes en 1965 à plus de 450 000 en 1997. Le secteur se compose principalement de deux sous-secteurs : la pêche industrielle et la pêche traditionnelle ou artisanale. Cette dernière, vielle de plusieurs siècles a su s’adapter et se moderniser au cours des dernières décennies. La flotte de pêche artisanale est dynamique et diversifiée ; selon les estimations, en 2005 il y avait plus de 13 000 pirogues. La pêche artisanale se concentre dans sept régions maritimes et fluviales du pays: Dakar, Thiès, Saint Louis, Fatick, Zinguinchor, Louga et Kaolack. Le port de Kayar dans la région de Thiès correspond à la principale zone de débarquement de la pêche artisanale avec environ 70% des débarquements. Dans le secteur industriel, les pêcheurs travaillent à bord d’une flottille de petits sardiniers, de 143 chalutiers destinés à la pêche d’espèces demersales, de 3 sardiniers et de 42 thoniers. Alors que le Sénégal domine largement le sous-secteur demersale avec 70% des chalutiers opérants, le pays ne possède que 6 thoniers contre 38 étrangers, dont une partie seulement des captures est débarquée au Sénégal. La pêche industrielle est concentrée autour de la capitale dans le Port autonome de Dakar et des ports secondaires de Saint Louis, Kaolack et Ziguinchor. Aujourd’hui, le secteur de la pêche sénégalaise est largement dominé par la pêche artisanale, qui constituait 90% des cargaisons totales des produits de la mer en 2006 avec 350 000 tonnes. Plus de 60% des produits de la pêche artisanale sont destinés à l’exportation et la transformation. En 2006, le secteur dans son ensemble représentait 9% du PIB du secteur primaire, 1.5% du PIB total, et 1/3 des devises étrangères (250 millions de dollars par an). Plus importante que le poids économique du secteur, est son poids social : la pêche génère indirectement 600 000 emplois, dont 67% au sein du secteur artisanal. En outre, les produits de la pêche comblent les besoins en protéines animales de la population sénégalaise à hauteur de 75%1. La pêche a connu une expansion spectaculaire au cours des dernières décennies grâce à l’impulsion de politiques publiques de développement basées sur une logique sectorielle productiviste. Une flotte nationale artisanale et industrielle a été progressivement mise en place ainsi que de fortes capacités de transformation industrielle. Cet engagement de l’Etat a ensuite connu un net ralentissement du fait, entre autre, des politiques d’ajustement structurel. Le renchérissement des coûts de production subséquents à la dévaluation du franc CFA en 1994 a lourdement affecté les pêcheurs. Parallèlement, avec la forte demande en produits halieutiques et en l’absence de politiques adéquates et cohérentes de gestion durable des ressources exploitables, une situation de surexploitation des ressources halieutiques s’est installée. En conséquence de la raréfaction des ressources halieutiques, la pêche sénégalaise traverse une crise sans précédent, dont les effets commencent à se faire sentir à tous les niveaux : appauvrissement des communautés de pêcheurs, menace de l’approvisionnement en poisson des populations, baisse des captures à haute valeur ajoutée, baisse des exportations, baisse de la rentabilité et des revenus des unités de pêche. Par ailleurs, de plus en plus d’établissements de transformation industrielle ferment (23 entreprises entre 1999 et 2006).
    Description: Ministerio de Medio Ambiente Y Medio Rural y Marino
    Description: Pablo Manuel Xandri Royo CTP Proyecto (INT/07/16M/SPA) Este trabajo se ha realizado en el marco del Convenio de Colaboración entre el actual Ministerio de Medio Ambiente y Medio Rural y Marino de España y la Organización Internacional del Trabajo de 28 de diciembre de 2007
    Description: Published
    Description: environnement; socio-économie; pêche; capture; débarquement; engin de pêche; femme; pêcheur; convention internationale; réglementation
    Keywords: Fisheries ; Marine environment ; Socioeconomic aspects ; Capture fisheries ; Landing statistics ; Fishing gear ; Women ; Fishermen ; Conventions ; Fishery regulations
    Repository Name: AquaDocs
    Type: Report , Non-Refereed
    Format: 208
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    Publication Date: 2021-05-19
    Description: Programme KURUKAN FUGAN (Union Européenne/Gouvernement du Sénégal/EndaGraf/GRET)
    Description: Published
    Description: politique de pêche; environnement marin; socio-économie; co-gestion; aquaculture; pêche artisanale; pêche industrielle; pêcherie; ONG; AMP; ressource halieutique; organisations professionnelles
    Keywords: Marine environment ; Socioeconomic aspects ; Fishery management ; Aquaculture ; Artisanal fishing ; Fisheries ; Industrial fish ; Fishery resources ; Fishing policy ; Protected areas ; Professionals
    Repository Name: AquaDocs
    Type: Book , Non-Refereed , Article
    Format: 26
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    Publication Date: 2021-01-30
    Description: Ministère des Affaires Etrangères (Sénégal); Ambassade du Sénégal à Rôme (Italy)
    Description: "Action 21"; FAO; application de l'accord; responsabilité de l'état du pavillon; échange d'informations; tiers à l'accord; règlement des différents; adhésion; entrée en vigueur; réserves; amendements; retraits; fonction du dépositaire.
    Keywords: Fisheries ; International agreements ; International cooperation ; Fisheries ; International agreements ; Maritime legislation ; International cooperation
    Repository Name: AquaDocs
    Type: Other
    Format: 14
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    Publication Date: 2021-09-18
    Description: En la época colonial algunas especies de peces cubanos retienen sus nombres por los cuales eran conocidos por los aborígenes: biajaca, biajaiba, cojinúa, jiguagua, cibí. Aún hoy se designan de igual forma. En esta época aparece la primera obra científica impresa en Cuba, los primeros pueblos pescadores y los primeros científicos.
    Description: Published
    Keywords: Fisheries
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed , Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    Publication Date: 2021-09-18
    Description: Published
    Description: especies nativas
    Description: pesca
    Keywords: Fisheries ; Indigenous species ; Indigenous fishing
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed , Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    Publication Date: 2021-09-18
    Description: Published
    Keywords: Fisheries
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed , Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    Publication Date: 2021-09-18
    Description: Recuento en forma breve de las pesquerías de estas especies durante varios siglos, en los cuales los sabios Parra y Felipe Poey ofrecen descripciones. Precios, lugares de captura y pescadores son los protagonistas.
    Description: Published
    Description: Emperador-Xiphias gladius
    Description: pez espada
    Description: castero-Makaira nigricans
    Description: aguja blanca-Tetrapturus albidus
    Keywords: Fisheries ; Fishes
    Repository Name: AquaDocs
    Type: Journal Contribution , Non-Refereed , Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    Publication Date: 2021-09-18
    Description: Causas del descenso en las pesquerías de estas especies a partir de 1975. Se describen las técnicas y artes de pesca empleadas y se abunda en la complejidad de las capturas y las características de los palangres empleados para cada especie. Una comparación es establecida además con países del área. De forma muy didáctica e instructiva.
    Description: Published
    Description: castero-Makaira nigricans
    Description: Emperador-Xiphias gladius
    Description: aguja blanca-Tetrapturus albidus
    Keywords: Fisheries ; Fishes
    Repository Name: AquaDocs
    Type: Journal Contribution , Non-Refereed , Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    Publication Date: 2022-05-26
    Description: Author Posting. © John Wiley & Sons, 2010. This is the author's version of the work. It is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Aquatic Conservation: Marine and Freshwater Ecosystems 21 (2011): 17-27, doi:10.1002/aqc.1158
    Description: 1. Interactions between cetaceans and fishing activity in the Archipelago of the Azores were examined using information contained in grey literature and previously unpublished data collected by observer programmes and research projects from 1998 to 2006. Together with a brief description of the economics, gear, fishing effort, and past and ongoing monitoring projects, levels of cetacean bycatch and interference were reported for each major fishery. 2. Cetaceans were present in 7% (n=973) and interfered in 3% (n=452) of the fishing events monitored by observers aboard tuna-fishing vessels. Interference resulted in a significantly higher proportion of events with zero catches but it was also associated with higher tuna catches. 3. There was a decreasing trend in the proportion of tuna-fishing events with cetacean presence or interference throughout this study, as well as a reduction in the estimates of dolphins captured annually by the whole fleet. 4. Observers reported cetacean depredation in 16% of the sets for demersal species and in 2% of the sets for swordfish. Cetacean presence and depredation were associated with higher overall catches and higher catches per unit effort in demersal fisheries. Bottlenose dolphins (Tursiops truncatus) were responsible for most depredation events in demersal fisheries, whereas in the swordfish fishery, depredation was associated with the presence of killer whales (Orcinus orca). There were no reports of cetacean bycatch in these fisheries. There were also no reports of cetaceans interacting in the experimental deep-sea fisheries that were examined. 5. Available data suggests that levels of interaction between cetaceans and Azorean fisheries are generally low and that the economic impact of cetacean interference is probably small. However, for several traditional fisheries there are no accurate data to determine levels of cetacean interaction. We recommend that existing observer programmes be expanded to increase observer coverage of the demersal and swordfish fisheries and allow monitoring of other existing and emerging fisheries.
    Description: M.A.S. was supported by an FCT postdoctoral (SFRH/BPD/29841/2006) grant, and R.P. was supported by an FCT doctoral grant (SFRH/BD/32520/2006).
    Keywords: Cetacean–fisheries interactions ; Depredation ; Bycatch ; Fisheries ; Atlantic Ocean ; Azores
    Repository Name: Woods Hole Open Access Server
    Type: Preprint
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    Publication Date: 2022-05-26
    Description: Author Posting. © Inter-Research, 2006. This article is posted here by permission of Inter-Research for personal use, not for redistribution. The definitive version was published in Marine Ecology Progress Series 310 (2006): 263-270, doi:10.3354/meps310263.
    Description: The longfin squid Loligo pealeii is distributed widely in the NW Atlantic and is the target of a major fishery. A previous electrophoretic study of L. pealeii was unable to prove genetic differentiation, and the fishery has been managed as a single unit stock. We tested for population structure using 5 microsatellite loci. In early summer (June), when the squids had migrated inshore to spawn, we distinguished 4 genetically distinct stocks between Delaware and Cape Cod (ca. 490 km); a 5th genetic stock occurred in Nova Scotia and a 6th in the northern Gulf of Mexico. One of the summer inshore stocks did not show genetic differentiation from 2 of the winter offshore populations. We suggest that squids from summer locations overwinter in offshore canyons and that winter offshore fishing may affect multiple stocks of the inshore fishery. In spring, squids may segregate by genetic stock as they undertake their inshore migration, indicating an underlying mechanism of subpopulation recognition.
    Description: We acknowledge funding from WHOI Sea Grant NA16RG2273, the Massachusetts Environmental Trust (#98-04), and the Sholley Foundation.
    Keywords: Fisheries ; Spawning migration ; Microsatellites ; Population structure ; Population recognition ; Null alleles
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    Publication Date: 2022-05-26
    Description: Author Posting. © Foundation for Environmental Conservation, 2009. This article is posted here by permission of Cambridge University Press for personal use, not for redistribution. The definitive version was published in Environmental Conservation 36 (2009): 268-276, doi:10.1017/S0376892910000032.
    Description: No-take marine reserves are widely recognized as an effective conservation tool for protecting marine resources. Despite considerable empirical evidence that abundance and biomass of fished species increase within marine reserve boundaries, the potential for reserves to provide fisheries and conservation benefits to adjacent waters remains heavily debated. This paper uses statistical and population models to evaluate published empirical data on adult spillover from marine reserves and shows that spillover is a common phenomenon for species that respond positively to reserve protection, but at relatively small scales, detectable on average up to 800 m from reserve boundaries. At these small scales, local fisheries around reserves were likely unsustainable in 12 of 14 cases without the reserve, and spillover partially or fully offsets losses in catch due to reserve closure in the other two cases. For reserves to play a role in sustaining and replenishing larger-scale fished stocks, networks of reserves may be necessary, but as few exist this is difficult to evaluate. The results suggest reserves can simultaneously meet conservation objectives and benefit local fisheries adjacent to their boundaries.
    Description: Support was provided by a grant from the David and Lucille Packard Foundation to NCEAS for ecosystem-based management ofmarine systems, the Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO) funded by the David and Lucile Packard Foundation and the Gordon and Betty Moore Foundation (contribution number 348), the Sustainable Fisheries Group supported by the Paul G. Allen Family Foundation and the Bahamas Biocomplexity Project (US NSF Biocomplexity grantOCE-0119976) andUS EPA Science to Achieve Results (R832223).
    Keywords: Adult fish movement ; Fisheries ; Global ; Marine protected areas ; No-take reserves ; Spillover effect ; Synthesis
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    ISSN: 1432-1009
    Keywords: Reservoir ; Fisheries ; Breeding and wintering waterbirds ; Raising water levels ; Habitat change
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract A new, higher dam was installed at Kerkini Reservoir in 1982, causing habitat and landscape disruption. A decrease in the area of grassland and shallow water areas, the rapid disappearance of reedbeds, the appearance of beds ofNymphaea, and the disappearance of half the forest area were all observed between 1982 and 1991. With the new hydrological regime, a lacustrine system was created, with an extensive, rather deep (4–8 m), pelagic zone favorable for the development of coarse fish species throughout the year. After 1982, an increase in fishing effort and a change in the relative abundance of fish species in the catch, including the disappearance of eels and wels, were observed. The impact of the rise in the water level of breeding aquatic birds led to a general decline in species typical of marshy habitats in favor of species preferring deeper open water habitats. A decrease was recorded in bird species that feed largely on invertebrates and to a lesser extent fish (e.g., glossy ibis) and that require extensive shallow feeding areas. There was a decline in geese, whose nests were regularly flooded, and a major increase in piscivorous birds, particularly diving birds (e.g., cormorants), which prefer deeper open water and benefitted directly from the large increase in coarse fish biomass. The disappearance of birds breeding in flooded meadows (e.g., black-winged stilts) and of those restricted to reedbeds (e.g., marsh harrier) occurred from 1983. Over the same period, the changes in populations of wintering birds at Kerkini were different from those occurring in other wetlands in northern Greece. The changes recorded in the populations of wintering birds at Kerkini did not therefore result from overall regional trends but from the major habitat modifications that occurred to this wetland. As for breeding birds, strictly piscivorous species increased greatly as a result of the increased availability of fish, but also due to the appearance of many suitable night roosting sites (flooded trees) and to the great increase in the area of open water greater than 2 m deep. Today, Kerkini has become the most important breeding site in Greece for a majority of colonial waterbirds. In contrast, wintering shorebirds practically disappeared. The many changes recorded in the status of breeding and wintering birds at Kerkini can mostly be explained by the changes that occurred in the functioning of the ecosystem and in the habitat structure following the inauguration of the new hydrological regime. These changes did not all occur at the same time: some were immediate and others required a delay before they could be detected.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    Electronic Resource
    Electronic Resource
    Springer
    Environmental management 7 (1983), S. 151-160 
    ISSN: 1432-1009
    Keywords: Grass carp ; Biological control ; Nuisance aquatic weeds ; Fisheries ; Aquaculture ; Reproductive requirements ; Arkansas management plan ; Sterile hybrids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Grass carp (Ctenopharyngodon idella Val.) were introduced into the United States in 1963 as potential biological control agents for nuisance aquatic weeds. Since that time an oftentimes bitter controversy has raged over its effects on sportfishing, and its possible natural reproduction and naturalization in North America. This review considers the history, ecology, and present status of grass carp in the United States in light of the voluminous scientific research conducted since its importation. Particular attention is given to the role of grass carp in the fisheries management plans of Arkansas. Recent development of a sterile, triploid grass carp hybrid may lead to widespread use of grass carp to control nuisance aquatic weeds in culturally eutrophicated waters of the United States.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    Electronic Resource
    Electronic Resource
    Springer
    Environmental management 20 (1996), S. 523-539 
    ISSN: 1432-1009
    Keywords: Water control ; Floodplain ; Fisheries ; Bangladesh ; Chandpur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Bangladesh is a very flat delta built up by the Ganges—Brahmaputra—Meghna/Barak river systems. Because of its geographical location, floods cause huge destruction of lives and properties almost every year. Water control programs have been undertaken to enhance development through mitigating the threat of disasters. This structural approach to flood hazard has severely affected floodplain fisheries that supply the major share of protein to rural Bangladesh, as exemplified by the Chandpur Irrigation Project. Although the regulated environment of the Chandpur project has become favorable for closed-water cultured fish farming, the natural open-water fishery loss has been substantial. Results from research show that fish yields were better under preproject conditions. Under project conditions per capita fish consumption has dropped significantly, and the price of fish has risen beyond the means of the poor people, so that fish protein in the diet of poor people is gradually declining. Bangladesh is planning to expand water control facilities to the remaining flood-prone areas in the next 15–20 years. This will cause further loss of floodplain fisheries. If prices for closed-water fish remain beyond the buying power of the poor, alternative sources of cheap protein will be required.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    Electronic Resource
    Electronic Resource
    Springer
    Environmental biology of fishes 7 (1982), S. 177-180 
    ISSN: 1573-5133
    Keywords: Temperature ; Behavior ; Ecology ; Fisheries ; Fish ; Marine juveniles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Sixteen yearling winter flounder, tested individually for 3-day periods in electronic shuttleboxes, voluntarily occupied an 8–27°C range of temperature, with a modal final thermal preferendum of 18.5°C (mean 18.7°C, median 19°C, midpoint 17.5°C, s.d. 1.9°C, S k + 0.33). The locomotor activity pattern of the yearling fish in the laboratory was markedly nocturnal, with mean hourly nocturnal activity exceeding mean hourly diurnal activity by a factor of 3.4. Maximum activity occurred at 0300 EST, minimum activity at 1400 EST. While activity generally increased with temperature, a local activity minimum occurred at 18.7°C, coinciding with the 24-hour mean final thermal preferendum. Comparison of these laboratory data with previously published field data suggest that behavioral responses to temperature and light play significant roles in determining age- and size-specific differences in seasonal depth stratification and onshore-offshore distributions in this species.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    Electronic Resource
    Electronic Resource
    Springer
    Environmental biology of fishes 45 (1996), S. 219-235 
    ISSN: 1573-5133
    Keywords: Ecology ; Behaviour ; Evolution ; Cichlids ; Fisheries ; Conservation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Ecological conditions in tropical lacustrine systems are considered by focusing on the evolution, maintenance, exploitation and vulnerability of fish communities in the African Great Lakes. The exceptionally high biodiversities in the littoral/sublittoral zones of the very ancient, deep, clear, permanently stratified rift lakes Tanganyika and Malawi, are contrasted with the simpler systems in their pelagic zones, also with biodiversity in the much younger, shallower Victoria, the world's largest tropical lake.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    Electronic Resource
    Electronic Resource
    Springer
    Environmental biology of fishes 43 (1995), S. 381-391 
    ISSN: 1573-5133
    Keywords: Fisheries ; Irrigation ; Reproductive seasonality ; Sarotherodon galilaeus ; Species richness ; Water quality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis A preliminary study of the ecology and commercial fish catches was carried out in the Toho-Todougba, Ahouangan and Dati lakes (1500 ha) in southern Benin (West Africa) over a period of 18 consecutive months. Water quality, species richness, and the reproductive biology of the dominant species, Sarotherodon galilaeus, were examined. Unlike Lagoon Toho-Todougba, lakes Ahouangan and Dati are less favourable for fish production because of their high total iron content and their relative low pH. The study revealed the existence of 19 species belonging to eleven (11) families: 16 species in Lagoon Toho-Todougba,12 in Lake Ahouangan, and 7 in Lake Dati. Lakes Ahouangan and Dati had a relatively high faunal similarity whereas Lagoon Toho-Todougba exhibited a relatively low faunal similarity with the former systems. In Lagoon Toho-Todougba, six cichlid species were the most important component of the fishery: Sarotherodon galilaeus, Tilapia guineensis, T. zillii, T. mariae, Chromidotilapia guntheri, Hemichromis fasciatus. Three catfish species Chrysichthys auratus, Clarias agboyiensis, and Clarias lazera were harvested in low abundances. Some other fish, such as Polypterus senegalus senegalus, Protopterus annectens and Heterotis niloticus were captured sporadically, with H. niloticus appearing more consistently in catches than the others. Although not abundant, Gymnarchus niloticus and the African pike, Hepsetus odoe, were almost always present in the catches. Ctenopoma kingsleyae appeared only in Ahouangan. Some predatory species, such as Notopterus afer and Xenomystus nigri, are encountered only in lakes Ahouangan and Dati. In Lagoon Toho-Todougba, Sarotherodon galilaeus had a sex ratio (♂: ♀) of 0.49:1, and size at maturation was estimated as 12.3 cm TL. The spawning period extended from May to September with the peak occurring in July. Fecundity was correlated to log-body length (r = 0.74) and log-body weight (r = 0.76). Fish catches were estimated at 389 kg ha−1 year−1; about 73% of which was Sarotherodon galilaeus. The overexploitation of juvenile fish and the use of this lagoon for the irrigation of palm tree plantations have reduced fish recruitment and mean size.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    Electronic Resource
    Electronic Resource
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 35 (1995), S. 1807-1810 
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Blends prepared from poly(ethylene 2,6-naphthalate) (PEN) and poly(butylene 2,6-naphthalate) (PBN) show only partial miscibility judged from their glass transition temperatures. Two distinct mechanical behaviors are observed: brittle for the blends 〈 20 wt% of PBN, while ductile 〉 20 wt% of PBN. The experimental modulus and strength values of the blends are within the predicted values according to Kleiner and Paul models, respectively. This means that PEN/PBN blends are somewhat compatible based on their tensile properties. Especially for 20 wt% of PBN blend, the high modulus and strength are observed. The viscosity of the blend is high, which may imply a somewhat entangled morphology in the amorphous state.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    Electronic Resource
    Electronic Resource
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 35 (1995) 
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    Electronic Resource
    Electronic Resource
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 35 (1995), S. 1821-1833 
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The paper consides the effects of compatibilization with maleic anhydride grafted polypropylene (PP-g-MAH) on the propertie of immiscible blends of polypropylene (PP) and nylon 6 (N6). We prepared the blends by three different mixing processes; single-step blending, two-step blending with reactive premixing, and two-step blending with nonreactive premixing, to determine the effective mixiing process for fine morphological structure thermal stability, and mechanical properties. Dynamic melt reheological properties were measured to examine the modification of elastic properties by the compatibilizer. In addtion, thermal analysis was also carried out to detect the change in crystallization and thereby to probe the degree of compatibilizaton. The results show that compatibilized blends prepared by teh single-step process exhibit improved phase morphology, thermal stability, and mechanical properties for dried conditions, compared with other blend types. Finally, the water absorption test indicates that the added compatibilizer yields enhanced water resistance in spite of the strong intrinsic hydrophilicity of N6. In particular, two-step blending with reactive premixing is most effective in improving water resistance and reducing degradation of mechanical properties after moisture absorption.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    Electronic Resource
    Electronic Resource
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 35 (1995), S. 1834-1851 
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A hybrid two-/three-dimensional solution technique is presentedto model 3-D flow fields in resin transfer moeling using Darcy's low. The 3-D flow field is only solved for regions where all three velocity components are significant, thus largely reducing the number of unknowns. Elsewhere, the commonly used 2-D approximation for flow in thin gaps between plates is employe.d The method is applied to regions where the flow splits, such as T-joints. Because of the uncertainties associated with an accurate determination of the permeability in these regions, a simplified decompled procedure is procesed, which reduces the computational complexity. In this procedure, the flow front is advanced using the 2-D formulation. The 2-D formulation also provides the boundary conditions for the subsequent computation of the 3-D flow field without feedback of flow field information to the 2-d model. The governing equations are solved using boundary fitted coordinate systems (BFCS) together with the finite difference method (FDM). Numerical as well as algebraic grid generation and domain decomposition are employe dto generate grids that always concide with the continuously deforming and enlarging flow domain. Results that include the trackingof numerical tracer particles to visualize the three-dimensionality of the flow field are presented for isothermal flow of a Newtonian fluid through a T-joint. This detailed flow field description is expected to form the basis for a rather accurate simulation of quantitities that largely depend on the fluid particle pathlines, such as the degree of cure. The method is also extendable to shear-thinning fluids as well as to 3-D flow in the vicinity of the flow front.
    Additional Material: 22 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 57
    Electronic Resource
    Electronic Resource
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 35 (1995), S. 1872-1877 
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The Smoluchowski equation for the breakup and coalescence of dispersed droplets has been solved for flowing polymer blends. A scaling form for the distribution of droplet sized derived and published for a system of clusters with fragmentation and coagualation was used in our dervation. Equations are developed here for the average droplet size and for the characteristic time of transition to steady state flow of blends with a high content of the dispersed phase. Expressions reasonably describing the average size of droplets for all concentrations were obtained by a theory modification. Measured dependences of droplet size on the blend composition can be matched only if simultaneous collisions of three and more droplets are considered. The results of the theory indicate that the mechanism of droplet breakup (formation of pieces with the same or different volumes) has only a small effect on their average size in concentrated systems. The dependence of droplet size on the shear rate in flow is determined by properties of the blend components, and is generally nonmonotonic.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 58
    Electronic Resource
    Electronic Resource
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 35 (1995), S. 1878-1883 
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Multilayer LDPE/nylon-6 films with an overall content of 71 wt% LDPE, 24 wt% nylon-6, and 5 wt% PE-based tie-layer adhesive were reprocessed under both minimal and extensive mixing conditions. Thermal and mechanical properties, oxygen and water vapor permeability, and morphology of the reprocessed samples were determined. The modulus and yield stress of the reprocessed films fell between those of the pure homopolymers, whereas percent elongation at break and energy-to-break for all reprocessed films were less than those of the homopolymers. In minimally reprocessed film, layering of LDPE (low-density polyethylene) and nylon-6 was retained, whereas in extensively mixed samples, nylon-6 domains were spherical and ranged from 0.2 to 7 μm. Minimally reprocessed film exhibited good O2 and H2O vapor barrier properties, whereas extensively-mixed samples had poor barrier properties. Properties of well-mixed blends prepared both with and without adhesive showed that 5 wt% adhesive did not compatibilize the LDPE and nylon-6 components.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 59
    Electronic Resource
    Electronic Resource
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 35 (1995), S. 1895-1898 
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A new stress monitoring technique, a stress-tracking device, is described here. It has been used to study some important properties of epoxy resin. Residual stresses, including a curing shrinkage stress and a cooling shrinkage stress, were measured automatically and continuously during curing and cooling. Simultaneously, information such as an apparent gelation time and glass transition temperature were obtained directly during the experiment. These epoxy resin properties were related to the extent of cure. Varying cure temperature produced changes of cure behavior, which resulted in different residual stresses.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 60
    Electronic Resource
    Electronic Resource
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 35 (1995), S. 1899-1906 
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Processing of microcellular foam was investigated for the feasibility of production of tough and lightweight polyurethanes. To increase the nucleation rate in a gas-supersaturated resin, ultrasonic excitation was applied to the mixture of polyol(polyether-based polyol) and isocyanate(diphenyl methane diisocyanate). A microcellular structure was produced by two sequential steps, i.e., supersaturationof the polyol resin with nitrogen gas at elevated pressure and ultrasonic bubble nucleation right after the impingement mixing of two components of the polyurethane system. Theoretical analyses based on nucleation theories were employed to predict the rate of nucleation in the gas-supersaturated polyurethane. The rate of nucleatio in the resin was predicted by classical nucleation and cluster theories. In the experimental investigation, ultrasonic excitation was applied to increase the nucleation rate in the resin that had been saturated by nitrogen at a saturation pressure 〈 2.0 MPa.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 61
    Electronic Resource
    Electronic Resource
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 35 (1995), S. 1917-1922 
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Polypropylene/Polyamide-6 (PP.PA) blends containing maleic anhydride grafted elastomers were prepared by reactive blending. Three different types of core shell morphologies were obtained and characterized by transmission electron microscopy (TEM). The midulus of these elastomer midified PP/PA (70/30) blends with core shell type morphology is compared to predictions derived from the Kerner model. The multiphase morphology of these blends could be modeled by sequential application of the Kerner equation to two-phase subinclusions. Using morphological data ontained by TEM, good agreement between experimental and calculated values was ontained. The results are used to tailor PP/Pa-6 blends combining stiffness and toughness.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 62
    Electronic Resource
    Electronic Resource
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 35 (1995), S. 1931-1937 
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: One of the major factors limiting the use of thermoplastics in engineeing applications is the inadequacy of existing design data. Much of the data do not span appropriate ranges of stress, strain, time, or temperature. This study addresses the need to develop an accelerated method for generating long-time design data to support the innovative use of engineering thermoplastics. In particular, stress relaxation tests (SRT) were performed on polycarbonate (PC) and midified poly(phenylene oxide)(PPO), and used to generate time-dependent design data through the short-time measurement of the material's current state without dependence on elastic modulus. The test results and analyses reported here indicate the SRT method to be an efficeint means of generating accurate and repeatable creep and secant modulus data which may be directly used in design. Therefore, SRT shows great potential both as a design parameter development tool, and as a quality control instrumetn for assessing batch-to-batch variability.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 63
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 40 (1925) 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 64
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 40 (1925), S. 517-557 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: An early segregation of germ cells and migration through a germ track into the gonad does not occur in the albino rat. The germ cells are produced only from the peritoneum of the genital region and their earliest formation is coincident with the thickening of the coelomic epithelium to form the genital ridge. This takes place eleven days after insemination in embryos of approximately 18 somites. Germ cells continue to form from the peritoneum during the early development of the gonad. The peritoneum of this region also produces mesenchyme, smaller cells of the gonads, and the germinal epithelium.The argument for the specific character of the germ cells in vertebrates and their continuity from the egg is based largely upon assumption, and not upon substantial observations, and must be discarded. Germ-cell origin is a problem of cellular differentiatio, and not of early segregation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 65
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 41 (1925), S. ii 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 66
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 41 (1925), S. 191-216 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Painted turtles, gopher tortoises, and terrapins were fed on various mixtures of sand, salts, dextrin, casein, cod-liver oil, wheat, eggs, lettuce, and meal worms. Each individual was weighted weekly for about a year and then killed for analysis, the water, ash, nitrogen, and fat being determined. Some individuals increased in weight as much as 75 per cent, others lost weight. Judged by growth and chemical analyses, the food requirements of chelonians, as representative poikilothermal vertebrates toward nutritive substances (including vitamines) are similar to those of homoiothermal animals.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 67
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 41 (1925), S. 267-281 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Of the eggs laid by Fasciolaria about 1 per cent develop into veligers, about 2 per cent more undergo a few cleavage divisions, and about 97 per cent do not divide at all. The 99 per cent that fail to develop normally are ‘swallowed’ by the veligers. This study concerns itself chiefly with the ova that do not divide. Notes on normal development and on the ova that undergo atypical cleavage are included.All of the ova are found to be typical when passed from the ovary. To each ovum one to several sperms become attached at the vegetal pole in the region of a mass of undifferentiated protoplasm - the ‘polar mass.’ A fertilization cone forms in each ovum and a fertilization membrane. In typical development a yolk lobe is formed, the sperm enters in the usual way, and fertilization is completed as in many other mollusks. In 97 per cent of the ova the yolk lobe is not formed and the sperm does not enter. In these cases the wall of the egg nucleus remains intact a long time. The nucleus itself and the ‘polar mass’ sink into the egg and meet at the center. Then the nuclear wall disappears and an atypical diaster is formed. However, cleavage is not begun and the chromosomes form vesicles that remain near the center of the ovum until it is ‘swallowed’ and digested by the veliger.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 68
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The blood of Perophora viridis is found to contain six types of cells: (1) Green cells, which have green-colored fatty bodies embedded in clear cytoplasm. (2) Orange cells, with orange-colored bodies of unknown composition in the cytoplasm. (3) Colorless berry-like cells, with fluid-filled vesicles in the cytoplasm. (4) Granular amoeboid cells. (5) Compartmental amoeboid cells, which have box-like vacuoles containing brownian granules of a fatty substance. (6) Vesicular, signet-ring type of cell having a single large vacuole. The cytological structure of these cells and their reaction to various dyes are described.An effort has been made to homologize the types of cells found in the blood of other ascidians with those found in Perophora.It is concluded that the variety of colors found in the cells of ascidian blood is due to the varying chemical states of the vanadium-containing chromogen present in the cells.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 69
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 42 (1926) 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 70
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 42 (1926), S. 111-141 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Disintegration in killing agents was studied throughout development. In the unfertilized egg and cleavage stages the death gradient runs from animal to vegetal pole. In the late blastula stage the future dorsal surface and future point of gastrulation show heightened susceptibility. The gastrula has a gradient from anterior to posterior end along its dorsal surface, with a slight reverse gradient around the blastopore; lateral and ventral regions are least susceptible.Before and after the appearance of the neural groove, the dorsal surface shows increased susceptibility with gradient in it from anterior to posterior end. The neural tube is highly susceptible, with a death gradient from anterior to posterior end and a slight reverse gradient at its posterior end.During late stages and in the larva the double gradient is present; death begins at the two ends and progresses backward from head, forward from anus; from the former most rapidly. The least susceptible place is near the posterior end. The posterior reverse gradient is less developed in the lamprey than in other vertebrate embryos, due, probably, to its lack of a tail bud.Assuming that death differences indicate differences in rate of activity, it appears that such differences in activity may be causes and not results of developmental processes, for the development of certain parts (dorsal surface, blastopore, central nervous system) is indicated by heightened activity before it is evident morphologically.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 71
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 42 (1926), S. 83-109 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The summary of this paper is as follows:1A critical review of the developmental evidence shows that the branchial pouches are formed in cephalocaudal sequence subsequently to the segmentation of the dorsal mesoderm.2The pouches interrupt a continuous sheet of mesoderm to form the branchial arches.3The arches when formed do not correspond topographically to the dorsal somites.4Branchiomerism does not therefore coincide with somitic metamerism.3The branchial structures do not support the theory of head segmentation.3The nervi trigeminus, facialis, glossopharyngeus, and vagus cannot be regarded as segmental nerves.3There is no evidence that branchial pouches or arches have been elided from the series.3The problem of meristic homology is briefly discussed.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 72
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 43 (1927), S. 521-546 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The literature on the general subject of freezing and survival both in plants and in animals is briefly reviewed and a bibliography given. Insects representing three ecological groups, (1) the oak borers - exposed to temperature extremes normally; (2) stored-products insects representing supposedly a tropical or subtropical group, and, (3) aquatic insects never exposed to temperatures lower than 0°C., were chosen for this study. Determinations of the freezing and undercooling points were made during the yearly cycle.Both the stored-products insects and the aquatic insects studied showed no periodicity in freezing or undercooling. The oak borers showed marked periodicity. The freezing-point varies directly with the moisture content. Cold-hardiness was produced experimentally by, (1) exposure of insects to low temperatures and, (2) by dehydration. Loss of cold-hardiness was produced experimentally by combinations of high temperature, food, and high relative humidity. The freezing-point ordinarily found corresponds with that of the blood. Repeated freezings of the same insect or tissue showed no hysteresis. There exists in certain insects a secondary freezing-point below that ordinarily found. Oak borers in summer condition die at the first freezing-point; in fully hardened condition they die at the secondary freezingpoint.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 73
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 44 (1927), S. 1-20 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The ant Formica exsectoides F. builds mounds with some reference to sunlight, and measurements of internal temperatures have shown them higher in upper parts of the mound, but different in different faces of the mound - all higher than the earth outside the mound.Inside temperatures are not constant; they are due to the sunshine. The mound is so fabricated that the internal temperatures are conserved during the night. The ants make use of the differential internal temperatures for rearing broods.Some mounds show bilateral symmetry dependent upon sun exposure.Measurements of rate of running of these ants show a falling off with lower temperatures, and possibly this is one factor in the smaller development of northerly aspects of these mounds.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 74
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 44 (1927), S. 117-125 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In the early cleavage stages of Ascaris the homologous chromosomes are of unequal length. Measurements show that these homologues fall into two sharply defined groups suggesting their biparental origin. The shorter are considered to have come from the male.As the age of the embryo increases, these differences between the chromosome mates tend to become less, and it is suggested that at some later period in the history of the animal this difference will entirely disappear in response to the effect of continued existence in a common environment. The length of the chromosomes is very slightly shortened during the early cleavage divisions, while the area of the equatorial cross-section of the cells becomes enormously reduced.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 75
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 44 (1927), S. 313-339 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The rates of oxygen consumption of single pupae of blowflies (Phormia terraenovae, Phormia regina, Lucilia sericata), of the flesh fly (Sarcophaga sarracenioides Aldrich), of the Mediterranean flour moth (Ephestia kuehniella), and of the bee moth (Galleria mellonella) during metamorphosis, until emergence, have been determined. The record for each pupa, with the exception of those of blowflies, is practically continuous day and night during the period of pupal development which lasted from 140 to 300 hours, according to the species, at the temperatures used. During pupal development there is first a period of decrease in rate, which is later followed by a steady increase until a short time before emergence, when a sudden decrease occurs.The ‘oxygen curves’ of the blowfly pupae (Diptera) are quite different from those of the flour-moth and bee-moth pupae (Lepidoptera), although all are of the same general U-shaped type. There are strong indications of a specific difference in the curves of the blow-fly pupae. The flour-moth pupae curves differ slightly from those of the bee-moth pupae. During the major part of development the rates of O2 consumption of pupae of both sexes of bee moth and flour moth are about the same, but near the end of metamorphosis the females have higher rates than the males. No such sex difference appears among the dipterous pupae used.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 76
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 44 (1927), S. 363-372 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The history of investigations on the contractile vacuole is reviewed briefly and brought up to date.The study of the contractile vacuole in Amoeba proteus is considered from standpoints of origin, structure, behavior, and function. The results are obtained from a prolonged study of normal organisms and from their reactions when introduced into conductivity water.The origin of vacuoles is studied by means of dark-field illumination which reveals the vacuole to be formed from a fusion and coalescence of extremely minute droplets.The retaining ‘wall’ of the contractile vacuole is not a permanent structure, but is in the nature of a condensation membrane, totally disappearing with each contraction.The loci of the contractile vacuoles are not permanent, but vacuoles are formed more or less at random. It is unlikely that they are supported in gelated areas, for amoebae with a dozen vacuoles are quite active and there is no interference with amoeboid movement.Conductivity water increases the size, number, and rate of contraction of contractile vacuoles, which suggests that they may function in maintaining an osmotic gradient as well as in the elimination of metabolic waste.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 77
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 44 (1927), S. 467-514 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The eggs of Corella develop in the atrial chamber of the parent at a pH below that of normal sea-water (pH 7.4 ±). When removed to normal sea-water in early stages and under certain other experimental conditions, larval development is more or less inhibited, the tail being most inhibited, the dorsal region somewhat less. The free larval stage may be eliminated and later development and metamorphosis may proceed normally to an advanced stage in the chorion and give rise to normal ascidians. The region most inhibited are, in general, those which possess the highest reducing power, as indicated by KMnO4. Experiments made in the attempt to control development all agree in indicating that the early stages are adjusted to a certain CO2 concentration approximately that of the atrial chamber and presumably near that of the body. Solutions of the same pH may or may not inhibit development according to their CO2 content.The tail, the region of highest reducing power in the embryo during its development, is most inhibited; the dorsal region, the next most rapidly reducing region, is next in degree of inhibition. All differences in reducing power disappear when, or soon after, the animals are killed by other agents before treatment with KMnO4.
    Additional Material: 64 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 78
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The claspers of Centrina are adnate with the pelvic fin and bear a spine as in other Spinacidae. Mustelus canis resembles M. lunulatus rather than M. vulgaris. The claspers of Chiloscyllium end in a pointed spike. Pseudotriakis resembles the Carchariidae. The three North American Atlantic species of the genus Raia are considered, and R. laevis and R. erinacea are placed in the pseudogenus containing R. batis, and a new pseudogenus erected for R. ocellata. A gross and histological account is given of the Cowper's glands of Homo, and they are shown to be homoplastic with clasper glands, similar in structure, arrangement, development, and function.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 79
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In the golden-mantled ground-squirrel, Callospermophilus, a spatulate glandular area has been noted in the skin of the back. It has been found in the following species: C. l. lateralis, C. l. arizonensis, C. l. caryi, C. l. saturatus, C. l. tescorum, C. c. chrysodeirus, and C. bernardinus. Probably it is common to the genus.The individual glands making up this area are modified and enlarged sudoriparous glands. They are divided into a tightly coiled and branched fundus, a large sinus, and a duct which passes caudad and outward to its exit at the surface.The glands secrete a strongly smelling oil, which is probably left on vegetation and other objects in the animal's environment and serves as a source of information to other members of the species. The glands are more active in spring and summer than in winter. They are stimulated by excitement. While present in both sexes, both adult and juvenile, they are best developed in adult males.Callospermophilus has three anal glands. These have flat-topped, straight-sided nipples which are protruded from the anus if the animal is frightened. A milky substance with a very weak odor can be extruded.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 80
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The study is divided into three parts. Part I deals with the chromosome number and morphology in the amniotic cells of rabbit embryos. The number of chromosomes has been found essentially constant in amniotic cells of young, but more variable in older embryos. The somatic number is 44. Part II deals with the chromosomes of race crosses (Flemmish Giant X Polish) in which the homologous chromosomes were found to be alike. Part III deals with spermatogenesis. There are forty-four chromosomes in spermatogonia, and twenty-two in primary spermatocytes. The sex chromosomes are of the usual X-Y type.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 81
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: 1Monovalent cation salts induce reversal in the direction of the stroke of the cilia; bivalent and trivalent cation salts with a few exceptions do not. Some acids induce reversal, others do not.2The duration of reversed action varies with the kind of salt and with the concentration. As the concentration increases, the duration of reversed action increases to a maximum and then decreases to zero.3Bivalent and trivalent cation salts neutralize the effect of monovalent cation salts. The relative amount required varies with the kind of salt used and with the concentration.4The amount of a given salt required to neutralize another salt is not proportional to the concentration of the salt neutralized. Weber's law does not hold.5The results seem to indicate that ciliary reversal is associated with differential adsorption and consequent changes in electric potential, but that there are also other factors involved.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 82
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A special type of cell, called ‘Lichtzellen’ by Hesse, was found in the photosensitive regions of the earthworm. Wherever the epidermis is most sensitive to light these cells are most abundant. They are found in the epidermis of all segments of the body and also in nerve enlargements of the prostomium and the caudal segment, but the intersegmental and ventral regions of the different segments, except the more distal ones, contain none of them. They are supplied by nerves and each contains a characteristic inner structure, the optic organelle, composed of a large central hyaline structure, the lens, which is surrounded by a dense network of nerve fibrillae, the retinella. In hanging drops the lens was found to focus light in the region of the retinella irrespective of the direction of the rays.These cells are similar in structure and function to the visual cells in leeches. Available data indicate that these cells function as photoreceptors and that the fibrillae of the retinella are the direct receptors of light stimuli.Pigment is not associated with the photoreceptors in a way that suggests direct functional relationship, but there is a subepidermal pigment layer through which pinhole windows admit light along the path of nerves to each of the nerve enlargements containing photoreceptor cells. These windows open in such directions as to determine the direction of withdrawal of the worm.
    Additional Material: 18 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 83
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The effect of removal of the liver has been noted in fishes, frogs, and turtles. As in the higher vertebrates, removal of the liver produced a fall in blood sugar and a loss in muscular tone. The lower vertebrates failed to respond to intravenous injections of glucose, as do the birds and mammals. They also fail to respond to maltose or levulose. The liver maintained the blood-sugar level in the lower vertebrates, which is necessary for the maintenance of life.The mechanism of carbohydrate metabolism in the lower vertebrates may be different from that in the higher ones, in that glucose, when injected intravenously, apparently exercises a progressively less beneficial effect on the characteristic hypoglycemic condition which follows the removal of the liver of mammals and cold-blooded vertebrates.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 84
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 41 (1925), S. 239-265 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This paper reports experiments with Fundulus heteroclitus to modify larval development by means of ultraviolet radiation. Eggs were exposed to radiation at various intervals after fertilization for varying periods of time. The results accord with previous work on fish teratology, and the developmental types obtained are essentially similar to those produced by chemicals, cold, and hybridization. The deviations from normal development occur in the same body regions as do those in other vertebrates whose early development has been modified by the action of radiation (x-rays, radium, etc.).The results of these experiments indicate that there is a non-specificity in susceptibility relations with the production of similar types of monsters for widely different reagents. That these eggs are differentially susceptible to the action of ultraviolet radiation is indicated by the fact that those regions which have the highest metabolic activity when an inhibiting influence is active are the ones most generally affected. Thus modifications of the nervous system, sense organs, circulatory system, tail region, and body axis result, respectively, in the production of varying degrees of cyclopia, inadequate circulation, short, stubby or bent, non-motile tails (some bifid), and anterior twinning.As these modifications may be produced by applying inhibiting influences during the first few minutes after fertilization, it is evident that there is in the egg at this stage some constitutional or physiological basis which determines early differences in susceptibility of its various parts.
    Additional Material: 31 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 85
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 41 (1926), S. 427-439 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Webbing of toes or fingers in man is produced by a local arrest of development, causing retention of the normal embryonic webbing. This type of digital fusion involves only the skin, the skeleton being unaffected. The extensor tendons of the toes may sometimes be fused.Webbed digits occur normally in some marsupials, rodents, and insectivores, in a number of lemurs and catarrhines, and in the siamang and gorilla. They also may occur in varying degree in other Primates, notably Hylobates. An analysis of five new pedigrees together with those already published demonstrates that webbing of toes in man may be inherited in either a mendelian or sex-linked manner. In one case this character follows the course of the Y-chromosome.
    Additional Material: 19 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 86
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 45 (1928) 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 87
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Amoeba proteus was raised in a modified and diluted Ringer solution. When the pH of this culture medium became less than 6.0, the normal activities of the amoebae were interfered with; and when a still lower pH was attained, the amoebae died off. The same was true when the pH became greater than 8.0. At neutrality the activities were subnormal, very dark, and rounded. The rate of locomotion of amoebae raised in solutions with a pH less than 7.0 showed a maximum rate of locomotion at pH 6.6, which decreased as the pH changed in either direction, dropping to a very low rate at pH 7.0 and above and also below 6.0. For amoebae raised at a pH above 7.0 the rate was maximum at pH 7.6 and decreased as the pH changed in either direction; it was low at pH 7.0 and below and also above 8.0.On increasing the external osmotic pressure of the medium it was found that the effects caused varied somewhat with the hydrogen-ion concentration. Small increases in osmotic pressure decreased the rate from the normal at pH 6.0 and 8.0, increased it at pH 6.6 and 7.6, and did not affect it at pH 7.0. Osmotic pressures above that produced by M/20 lactose caused locomotion to cease in a short time at all pH values.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 88
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 45 (1928), S. 209-231 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The highly specialized cranial musculature of the toadfish is characterized by the following features: 1Absence of intermandibularis and branchiomandibularis muscles.2Presence of levator premaxillaris muscle.3Very large branchial chamber, the outer wall of which is formed by seven branchiostegal rays connected by a strong fascia provided with muscles (oblique levators and adductors).4Highly developed masticator muscles (adductor mandibularis and pterygoids).5The rectus abdominis, sternohyoid, and hyohyoid muscles are attached by a median aponeurosis to the hyoid and basibranchial elements and directly to the hypobranchial cartilages; this muscle complex depresses the buccal floor in opposition to the geniohyoid.6The pelvic fins are in the jugular position.7Two narrow muscles connect the cleithrum with the fourth ceratobranchial.8The cranial musculature is obviously adapted to a carnivorous habit and particularly for increasing respiratory capacity under asphyxial conditions.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 89
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 45 (1928), S. 293-398 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Blindfolded persons walk, run, swim, row, and drive automobiles in clock-spring spiral paths of greater or less regularity when attempting a straightaway. The spirals turn either right or left in one and the same individual, and may do so even in one experiment. But either right or left turns predominate in the great majority of individuals, often to a high degree. The paths show marked individuality, and there is some ground for thinking there exists a correlation between temperamental differences and general character of path.The mechanism which produces the spiral path is not located in the locomotor organs, but in the central nervous system and is probably identical essentially with the spiral mechanism in other motile organisms, all of which move in spiral paths when there are no guiding senses to direct the path. The clock-spring spiral in man is interpreted as the expression in two dimensions of space of a helical spiral mechanism which seems to exist in all motile organisms moving in three dimensions of space and in amebas which move in two dimensions. In a large number of lower organisms the number of body lengths per spiral turn is almost constant, being about 4.5. The smallest regular swimming spirals in man are very close to this value, but the smallest regular walking spirals are somewhat larger. The fundamental spiral mechanism seems to be of molecular dimensions, and there seems to exist a demonstrable locomotor bilateral asymmetry in very nearly, if not quite, all organisms.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 90
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 45 (1928), S. 473-503 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A detailed study has been made of the anatomy of one of the fingernail shells, and preliminary observations on the life-history have been carried out. In its general organization Sphaerium notatum is very similar to the larger fresh-water lamellibranchs. A gastric shield, crystalline style, and style sac, very similar to those found in the stomach and intestine of Lampsilis, are present. A pair of slender muscles extending from the dorsal side of the body into the gills, and evidently not previously described, have been found. The nervous system consists of the typical three pairs of lamellibranchiate ganglia, with their connectives, accessory ganglia, and nerve fibers. Particular study was given to the statocysts and osphradia, and attention is called to the fact that the function commonly ascribed to the osphradia is incompatible with their position in the roof of the cloacal chamber.S. notatum, like all the Sphaeriidae, is hermaphroditic and viviparous. The gonads are paired racemose glands lying behind and below the stomach. The sperm-producing follicles form the anterior portion of each gonad and are somewhat smaller and more numerous than the ova-producing follicles which form the posterior portion. The young pass through the early stages of development in brood pouches in the gills and are expelled as relatively enormous individuals.Preliminary observations on the life-history indicate that reproduction reaches its height in the summer and that fertilization probably takes place during the late summer and fall.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 91
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 45 (1928), S. 579-597 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: When Menidia eggs are fertilized with Prionotus sperm, the Prionotus chromosomes react in the Menidia cytoplasmic medium just as they do in the cytoplasm of Fundulus eggs. There is lagging, non-disjunction, and elimination of chromosomes during the early cell divisions. The mitotic behavior of the Prionotus sperm in the Menidia egg also resembles the behavior of the sperm of Ctenolabrus in the same medium. This behavior which was expected from what was known concerning the mitotic behavior of the reciprocal crosses between Menidia and Fundulus and between Ctenolabrus and Prionotus and other intercrosses between the members of these two groups is regarded as a function of the physical state of the egg cytoplasm during the division phase of mitosis. This physical character forms the earliest differential factor in the development of these hybrids and shows no correlation with the width of the cross.A comparison of nine teleost crosses, in which both the development and the early mitotic behavior are known, with a rough numerical estimate of the width of the cross brought out the fact that development is most successful in crosses between nearly related species if mitosis is normal and in distantly related crosses if mitosis is abnormal. This indicates that nuclear relationship is also a factor in the development of hybrids.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 92
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Virulent hay-infusion cultures of Bacillus pyocyaneus are toxic to pure-line races of three species of paramecia, but these races may acquire a tolerance for this toxic agent. Races with acquired tolerance have been grown for long periods of time in toxic, pure cultures of B. pyocyaneus by means of the daily-isolation culture method, and here the average division rate is as high as, or higher than, in the chance-mixed bacterial cultures in which these protozoa are usually maintained in the laboratory. The tolerance is lost, however, when the paramecia are removed from the toxic cultures and grown for a number of generations in cultures of non-toxic bacteria.The toxic agent that is lethal to paramecía is probably the soluble toxin of B. pyocyaneus. The investigation shows that the agent is soluble and either thermolabile or volatile. It also shows that all deleterious substances, other than the soluble toxin, known to be produced in cultures of this bacillus, are non-lethal to paramecia.Hay-infusion cultures of Bacillus enteritidis were lethal to paramecia. All attempts to develop tolerance in paramecia for the toxic agent in these cultures failed.Under the experimental conditions that prevailed, diphtheria toxin was found to have no appreciable effect upon the division rate or death rate in three species of paramecia.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 93
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 163 (1980), S. 99-133 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Study of the visceral anatomy of 41 specimens of amphisbaenians representing 13 genera shows that they share a very distinct structure which differs from that found in either snakes or typical lizards. The left lung is large while the right is rudimentary or absent (unique); the kidneys are freely suspended in the coelom by a mesentery (unique); the spleen is usually embedded in the anterior end of the pancreas (as in snakes); the gall bladder lies in a notch in the liver, and the kidneys lie opposite each other (as in lizards). The distinctness of this pattern supports the recognition of the Amphisbaenia as a separate suborder of the Squamata.
    Additional Material: 28 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 94
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 163 (1980), S. 175-190 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Light and electron microscope studies were made on harvestman oocytes during the course of their origin, differentiation, and vitellogenesis. The germ cells appear to originate from the ovarian epithelium. They subsequently migrate to the outer surface of the epithelium, where they remain attached often by means of stalk cells which suspend them in the hemocoel during oogenesis. The “Balbiani bodies,” “yolk nuclei,” or “nuage” constitute a prominent feature of young, previtellogenic oocytes, and take the form of large, but variable sizes of electron-dense cytoplasmic aggregates with small fibrogranular components. The cytoplasmic aggregates fragment and disperse, and cannot be detected in vitellogenic oocytes. The young oocytes become surrounded by a vitelline envelope that appears to represent a secretory product of the oocyte. The previtellogenic oocytes are impermeable to horseradish peroxidase under both in vivo and in vitro conditions. In addition to mitochondria, dictyosomes, and abundant ribosomes, the ooplasm of the previtellogenic oocyte acquires both vesicular and lamellar forms of the rough-surfaced endoplasmic reticulum. In many areas, a dense homogeneous product appears within the cisternae of the endoplasmic reticulum and represents nascent yolk protein synthesized by the oocyte during early stages of vitellogenesis. Later in vitellogenesis, the oocyte becomes permeable to horseradish peroxidase under both in vivo and in vitro conditions. This change is associated with a massive process of micropinocytosis which is reflected in the presence of large numbers of vesicles of variable form and structure in the cortical ooplasm. Both spherical and tubular vesicles are present, as are coated and uncoated vesicles. Stages in the fusion of the vesicles with each other and with developing yolk platelets are illustrated. In the harvester oocytes, vitellogenesis is a process that involves both autosynthetic and heterosynthetic mechanisms.
    Additional Material: 32 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 95
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 164 (1980), S. 25-38 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The clitellar epithelium of the freshwater oligochaete, Tubifex hattai, is composed of four types of gland cells (Type I, II, III, and IV), in addition to the cells generally found in the epidermis of this worm. The possible function of these gland cells in cocoon formation was studied with the electron microscope.Type I cells discharge their secretory granules by means of compound exocytosis and provide the materials for the future cocoon membrane. Immediately after completion of the discharge from Type I cells, Type II and III cells simultaneously discharge their secretory granules by means of compound exocytosis. The secretions from Type II cells constitute a colloid in the cocoon lumen and probably cause structural modifications in the future cocoon membrane. The secretory products from Type III cells form the cocoon plug. Although the process of discharge of secretory granules from Type IV cells was not observed, the contribution of these cells to the cocoon formation, producing hoops on the outer surface of the future cocoon membrane and fixing its anterior ends on the clitellum, is inferred from a morphological comparison of the hoop and the structure of the secretory granules.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 96
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 164 (1980), S. 69-81 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The distribution and activity patterns of monoamine oxidase and monoaminergic (formaldehyde-induced) fluorescence in the central nervous system of web-building and hunting spiders have been studied using histochemical methods. Enzyme activity occurred in the neuronal perikarya and in varying intensity in the structures of the neuropile mass, but only when dopamine, adrenaline, and noradrenaline were used as substrates. The optic centres of the spider brain normally exhibited relatively strong enzyme reactions when compared with the staining intensity of the rest of the nervous system.The neuronal cell bodies contained numerous granules of yellow-green fluorescence. Monoaminergic fluorescence of the neuropile was generally a weak green. The optic mases of the hunting spiders, the anterior bridge, several commissures of the ventral cord, and the neural lamellae showed a slightly higher fluorescence intensity and single fluorescing granules.The results obtained indicate the presence of catecholamines in the spider nervous system.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 97
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 164 (1980), S. 107-119 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The tongue of the striped dolphin, Stenella coeruleoalba, shows a V-shaped row of pits on its posterior dorsum. Their development is described on the basis of macroscopic and light microscopic observations on fetal, young, and adult stages. Four to eight pits occur, most often five in the adult. Anlagen of the pits first protrude as round epithelial thickenings which later increase in diameter and become thin. The circular primordia then sink, and grooves oriented both circularly and radially develop in the walls of the shallow pits thus formed. Pits and grooves deepen with development so that older pits become lined with conical projections. As pits grow further, they become elongated anterolaterally, retaining slit-like openings. Each pit in the adult is 2-8 mm long and about 1 mm wide. The pits are not derived from lingual gland ducts but develop independently. Taste buds resembling those of other mammalian tongues can be found in young dolphins but are few in number and limited to the thin epithelium of the pit projections and to that of the side wall of the pits. They first appear in the late prenatal period but degenerate in the adult. A rich nerve supply is observable in the lamina propria below taste buds in the calf. The pits and their projections in the dolphin correspond to the vallate papillae of other mammals, but whether each projection or a whole pit corresponds to a single vallate papilla is undecided.
    Additional Material: 22 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 98
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 164 (1980), S. 139-159 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Two morphologically distinct structures occur on the surfaces of the oral papillae in several loricariid catfish species; namely, (1) typical vertebrate taste buds composed of receptor and sustentacular cells and (2) brushlike projections, termed epidermal brushes, that represent specialized epidermal cells containing keratin. Both of these structures were studied with the combined use of light microscopy and scanning and transmission electron microscopy. The general body surface, fins, and rostral cutaneous processes of some loricariid catfishes are covered with taste or terminal buds but lack the epidermal brushes. It is suggested that the epidermal brushes found on the oral papillae serve as protective devices for the taste buds and as abrasive surfaces for substrate scraping during feeding. The taste buds on the oral papillae may detect any gustatory stimuli from the resulting substrate disturbance. Comparative studies reveal many differences in the number and spatial arrangement of these two structures on the oral papillae among the several species of the Loricariidae examined. These differences may represent functional adaptations to the various modes of life in the Loricariidae.
    Additional Material: 36 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 99
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 164 (1980), S. 83-88 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The Y-organ has been histologically identified in all six larval stages of the crab, Cancer anthonyi. The paired glands are located anterior to the branchial chamber and ventral to the base of the antennules. In the first zoeal stage the gland consists of a cord of 6 to 10 epidermal cells with dark staining nuclei, sparse cytoplasm, and indistinct cell boundaries. As development progresses the glands become more complex through extensive folding and intertwining of the cellular cords. The glands in all larval stages show cyclical activity which corresponds to the molt cycle. Immediately following a molt the gland is dense and compact with little cytoplasm. At approximately day four in the molt cycle, the glands become greatly hyperthropied due to an increase in the number and size of the cytoplasmic vacuoles. These histological changes suggests a cyclical production and presumably the release of some product most likely ecdysone.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 100
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 164 (1980), S. 89-105 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The digestive tract of a harpacticoid copepod, Tigriopus californicus (Baker), was studied by using techniques of light and electron microscopy. Four cell types could be distinguished: type 1, an embryonic cell which will replace cells worn away or lost during secretion; type 2, a cell which synthesizes and secretes proteins and also plays a role in lipid absorption; and types 3 and 4, two cell types which absorb lipids. From the abundance of each cell type, the length of microvilli, the development of basal plasma membrane (PM), and luminal projections, the following conclusions were made. (1) The midgut caecum absorbs digested nutrients. (2) The anterior midgut absorbs nutrients and more importantly functions in merocrine and exocrine secretion. The presence of concretions in cell types 2 and 3 in the anterior midgut suggests that these tissues contribute in excretion, and in water and/or ion regulation. (3) The posterior midgut absorbs nutrients and contributes some holocrine secretion.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...