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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Insectes sociaux 6 (1959), S. 203-218 
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Des renseignements sont présentés sur les périodes et les heures de vol deCubitermes ugandensis etC. testaceus en Ouganda oriental. Presque tout le travail s'est effectué au laboratoire. Les ailés retirés du monticule étaient grégaires et négativement phototactiques. L'emploi des ailes renversa ces caractères. Les ailés nevolaient que s'ils étaient hors de contact avec d'autres termites de la colonie et dans la lumière. Des observations ont été faites sur l'intensité de la lumière et l'activité de vol chezC. ugandensis. La pariade ou un essai de pariade stimula l'amputation des ailes chez les deux espèces, mais, du moins chezC. ugandensis, cette stimulation n'était pas obligatoire. Après l'amputation des ailes, les adultes se montraient indifférents à la lumière. Par l'enlèvement artificiel des ailes, on a démontré que le rapport entre la perte des ailes et la perte de la phototaxie positive chezC. ugandensis n'est pas direct. Il y a une discussion des moyens utilisé par les, adultes pour perdre leurs ailes. En général, chez les deux espèces, les femelles n'adoptaient la posture d'appel que lorsqu'elles s'étaient accouplées avec un mâle et l'avaient perdu. En l'absence des mâles, les femelles deC. ugandensis couraient activement pendant plusieurs minutes après l'amputation de leurs ailes, puis prenaient la posture d'appel entre d'autres périodes de déplacement rapide. On nota l'emploi par les femelles deC. ugandensis dans la posture d'appel de ce qui paraissait être un mécanisme défensif contre les petits prédateurs. La présence des ailes n'empêcha pas la pariade chez l'une ou l'autre espèce. Des tandems mâles se voyaient souvent, mais ils étaient presque toujours instables. On n'a vu ni de tandems femelles ni une femelle derrière un mâle. Les tandems ne montraient aucune géotaxie positive et restaient indifférents à la lumière. Les femelles deC. ugandensis tendaient à grimper et redescendre pendant quelques minutes après la pariade. La thigmotaxie était importante dans le choix de l'emplacement du nid chez les deux espèces. Le creusement paraissait dépendre de facteurs extérieurs et ne pas faire partie d'un schéma de comportement. Une fois l'emplacement du nid choisi, les couples redevenaient grégaires, mais ils ne se montraient absolument photonégatifs que lorsqu'ils s'étaient installés dans des cellules. Il y a une discussion sur la plasticité du comportement après le vol.
    Abstract: Zusammenfassung Die Arbeit berichtet über jahreszeitliche und tägliche Flugperioden vonCubitermes ugandensis und vonC. testaceus in Ost-Uganda. Die Untersuchungen wurden fast vollständig im Laboratorium ausgeführt. Geflügelte aus dem Nest genommen waren negativ phototactisch und hielten sich zusammen. Diese Eigenschaften wurden durch den Gebrauch der Flügel ins Gegenteil umgewandelt. Geflügelte flogen nur wenn sie nicht in Gesellschaft mit anderen Termiten des Baues und dem Lichte ausgesetzt waren. Beobachtungen wurden angestellt über Lichtintensität und die Flugfähigkeit vonC. ugandensis. Abwerfen der Flügel wurde in beiden Arten durch Paarung oder Paarungsversuche gefördert, hing aber, zum mindesten inC. ugandensis nicht von solcher Förderung ab. Auf das Abwerfen der Flügel folgte Gleichgültigkeit gegenüber Licht. Künstliche Entfernung der Flügel zeigte, dass beiC. ugandensis der Zusammenhang zwischen Flügelverlust und Verlust positives Phototaxis nicht direkt ist. Der Vorgang des Abwerfens der Flugel wird erörtert. Weibchen beider Arten nehmen im allgemeinen keine Lockstellung ein, bevor sie sich mit einem Männchen gepaart und es verloren hatten. Wenn Männchen fehlen, laufen Weibchen vonC. ugandensis nach Abwerfen der Flügel viele Minuten lebhaft herum, woraufhim zwischen weiteren Perioden lebhaften Laufens die Lockstellung eingenommen wurde. Eine mutmassliche Verteidungsmethode wenn im Lockstellung von Weibchen desC. ugandensis gegen Raubinsekten wurde beobachtet. Das Vorhandensein der Flügel behinderte Paarung in beiden Arten nicht. Männliche Tandems waren häufig, dauerten aber fast nie länger. Weibliche Tandems waren nicht zur Beobachtung, und es wurde nie beobachtet, dass ein Weibchen einem Männchen nachlief. Tandems zeigten keine positives Geotaxis und blieben gleichgültig gegenüber dem Licht. Weibchen vonC. ugandensis pflegten einige Minuten nach der Paarung auf- und abzuklettern. Thigmotaxis, war ein wichtiger Faktor bei beiden Arten in der Wahl eines Platzes für das Nest. Graben scheint von äusseren Faktoren abzuhängen und nicht Teil des Trieblebens zu sein. Der Trieb zur Vergesellschaftung kam mit der Wahl eines Platzes für das Nest wieder, aber deutliche photonegativen Verhalten wurde erst beobachtet, wenn die Paare sich in Zellen eingelebt hatten. Die Plastizität des Verhaltens nach dem Flug wird erörtert.
    Notes: Summary Information on flight periods and times of flight ofCubitermes ugandensis and ofC. testaceus in eastern Uganda is reviewed. All work was done in the laboratory with the exception of a few field observations on flight. Alates removed from the mound were negatively phototactic and gregarious. These characteristics were reversed by use of the wings. Alates would fly only if free of contact with other termites of the colony and in the presence of light. Observations were made on the flight activity ofC. ugandensis in connection with light intensity. Wing shedding in both species was stimulated by pairing or attempted pairing but, inC. ugandensis at least, was not dependent on such stimulation. Wing shedding was followed by indifference to light. Artificial wing removal demonstrated that inC. ugandensis the connection between loss of wings and loss of positive phototaxis was not a direct one. The method of wing shedding is discussed. Females of both spp. did not generally take up the calling attitude until they had paired with, and lost, a male. In the absence of males,C. ugandensis females would run actively for many minutes after wing shedding, after which the calling attitude was taken up between further periods of active running. An apparent defence mechanism against small predators, used byC. ugandensis females in the calling attitude, was noted. The presence of wings did not inhibit pairing in either species. Male tandems were frequent but nearly always very inconstant. Female tandems were not seen and no female was seen to follow a male. Tandems showed no positive geotaxis and remained indifferent to light.C. ugandensis females tended to climb up and down for some minutes after pairing. Thigmotaxis proved important in nest site selection by both species. Burrowing appeared to be dependent on external factors and not part of a behaviour pattern. Gregariousness returned with selection of the nest site but definite photonegative behaviour was not seen until the pairs were installed in cells. The plasticity of post-flight behaviour is discussed.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Insectes sociaux 6 (1959), S. 291-304 
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Environmental geology 3 (1980), S. 159-162 
    ISSN: 1432-0495
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract The Bunker Hill Mine in Idaho's Coeur d'Alene mining district produces approximately 10 m3/minute of acid water containing high concentrations of heavy metals. Field and laboratory studies indicate that much of the acid water is produced in a single ore body in the upper part of the mine. The ore of this body contains mainly sphalerite, galena, and pyrite in a siderite-quartz gangue. Ground water recharges this ore body through a near-vertical zone of high permeability, which is the result of mining by the caving technique. Ore samples from the caving area contained oxidized forms of iron and produced acid in a laboratory leaching test. Leaching experiments with several ore samples from the mine also indicated that the ratio of pyrite to calcite in the samples strongly controlled the resultant pH values. Oxidation of pyrite to sulfuric acid and compounds of iron is apparently responsible for the production of acid water in the mine. In contrast, dissolution of calcite in water results in a basic solution, with pH around 8.3, that can neutralize the acid produced by the oxidation process. Methods for prevention of acid mine drainage in this and other similar mines are noted.
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  • 4
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Decapod larvae and early post-larvae were extracted from detailed vertically stratified samples taken during research cruises in the Irish Sea from April to early June 1988 and in the North Sea in June 1989. The total dry weight of decapods was 4 to 106 mg m-2 which represented 0.5 to 8.6% of the total dry weight of zooplankton. The vertical distributions of abundant species were examined in relation to physical and biological variables.Nephrops norvegicus andPagurus bernhardus were found nearer to the surface during the spring bloom in April than after the bloom in May. In the near-surface waters of the North Sea in June, larvae ofLiocarcinus spp. were more abundant than those of other decapods. Diel migrations varied, apparently due to differences in the physical structure of the water column and the distribution of potential food. Conventional migrations were modified or absent in stratified areas when near-surface concentrations of chlorophyll were present and in well-mixed water. Few significant ontogenetic variations were found. The most striking case was ofLiocarcinus spp. larvae during the day in stratified water in the North Sea, where the early zoeal stages (at a mean depth of 〈6 m), the fifth zoeae (15.5 m mean) and the megalopas (26.7 m mean) occupied different positions in the water column.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Marine biology 79 (1984), S. 63-73 
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The vertical distribution and migration (seasonal, diel and ontogenetic) of Calanus helgolandicus are described from the shallow (100 m) shelf-seas to the south-west of the British Isles. In 1978 and 1979, the overwintering population of C. helgolandicus consisted primarily of Stage V copepodites and adults. By late winter/early spring the copepodites had moulted to adult females (〉90%), which matured and bred the first cohorts of the year, prior to onset of the spring phytoplankton bloom in April/May. C. helgolandicus reached a peak of numerical abundance in August of 20x103 copepodites m-2 (over the depth range sampled -0 to 70 m), which was 200 times the population in winter. The seasonal peak of abundance occurred 4 mo after the peak of the bloom of phytoplankton in spring. The yearly development of the copepod was not always out of phase with the diatom bloom, as seen when the data from 1978 was placed in the context of a longer time-series collected at 10 m over 22 yr (1960–1981, inclusive). Large vertical migrations were observed in the younger copepodites (CI and II) in May from below to above the thermocline. In the remainder of the year, the CI and CII stages behaved differently and were located above the thermocline within the euphotic zone. The largest vertical displacements of biomass were seen in the summer months due to the migrations of the CV stages and adults, which had developed from the spring cohorts. It was contended that the seasonal and vertical migrations of C. helgolandicus are part of a more complex pattern of inherent behavior than has been reported previously and that, however difficult this is to discern in the natural populations, it always expresses itself.
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  • 6
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Sprat (Sprattus sprattus) eggs and larvae were sampled from plankton and the Irish Sea in 1988 and 1989 and analysed forl-ascorbic acid (Vitamin C) content, which is considered an index of the nutritional well being and thus indicative of the status of the population in relation to environmental (physical and biological) structures. In one month, the Vitamin C content of larvae in different developmental stages decreased from 800 to 300µg g−1 in the youngest larvae (4 to 14 mm) and to 250µg g−1 in the oldest larvae (14 to 28 mm). No significant differences in the Vitamin C content per unit weight were found between larvae collected at four sites located in western stratified waters, central stratified, central mixed and eastern mixed waters. The mean Vitamin C content per larva, as well as mean length and wet weight of larvae were lowest in central mixed and eastern mixed waters in May–June. The estimated increases in Vitamin C, length and weight of individuals in the population of larvae varied significantly from April to June and between western stratified and eastern mixed areas. Highest rates coincided with stratified water conditions and with suitable quantity and quality of food, which seemed to constitute the most favourable environmental conditions for abundance and growth of sprat larvae.
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Marine biology 108 (1991), S. 373-385 
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The vertical distribution of chlorophylla, copepods, dissolved free amino acid concentration and the fixation of14C by phytoplankton were monitored in the springs of 1983, 1987 and 1988 in the Ushant front region, shelf edge of the Celtic Sea and central Irish Sea, respectively. In each area, two stations characterized by mixed and stratified water conditions were compared. Vertical distributions of amino acids coincided with the distribution of copepods. A positive and significant correlation was found between the abudance of copepods and the concentration of amino acids dissolved in seawater. A negative and significant correlation was found between chlorophylla and the concentration of amino acids. Enrichment of amino acids (≥ 20 to 500 nM l−1 at specific depths) due to aspartic and glutamic acids, glutamine and ornithine, was assumed to reflect copepod feeding activity and faecal production. At these depths, the natural concentration and diversity of amino acids, including aspartic acid, glutamic acid, asparagine, serine, histidine, glutamine, arginine, threonine, glycine, alanine, tyrosine, valine, phenylalanine, ornithine and lysine, were high enough and in the correct proportions for triggering feeding and swimming and swarming behavior of copepods, as well as their remote detection of food at the micro- and meso-scales (1 to 10 m). This accumulation of amino acids also constitutes a potential additional source of organic nitrogen for bacteria and phytoplankton.
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  • 8
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Samples taken in the northern North Sea with the Continuous Plankton Recorder (CPR), the Undulating Oceanographic Recorder (UOR), the Longhurst Hardy Plankton Recorder (LHPR) and by our colleagues from other participating Institutes during the Fladen Ground Experiment (FLEX 76) were used to describe the vertical distribution and population dynamics of Calanus finmarchicus (Gunnerus) and to provide estimates of the production and carbon budget of the population from 19 March to 3 June, 1976. Total production of the 19 March to 3 June, 1976. Total production of the nauplii and copepodite stages (including adults), during the exponential growth phase in May, was estimated to be in the range of 0.49 to 0.91 g C m-2 d-1 or 29.0 to 55 g dry wt m-2 (14.5 to 27.8 g C m-2) for the three successive 10 d periods in May. Two gross growth efficiencies (K 1) (20 and 34%), together with the lower value of C. finmarchicus production, were used to calculate the gross ingestion levels of algae as 2.45 and 1.44 g C m-2 d-1 (73.5 and 43.2 g C m-2 over the May period). These ingestion levels, together with the algae ingested by other zooplankton species, are greater than the estimated total phytoplankton production of 45.9 g C m-2 over the FLEX period. A number of factors are discussed which could explain the discrepancies between the production estimates. One suggestion is that the vertical distribution of the development stages of this herbivorous copepod and their diel and ontogenetic migration patterns enable it to efficiently exploit its food source. Data from the FLEX experiment indicated that the depletion of nutrients limited the size of the spring bloom, but that it was the grazing pressure exerted by C. finmarchicus which was responsible for the control and depletion of the phytoplankton in the spring of 1976 in the northern North Sea.
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  • 9
    Electronic Resource
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    Springer
    Marine biology 60 (1980), S. 57-61 
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The vertical distributions of the spring populations of Calanus finmarchicus (Gunnerus) and C. helgolandicus Claus are described and compared. The differences we observed between the two species have probably confused the understanding of the vertical distribution and development of the populations of Calanus spp. in the shelf seas around the United Kingdom where the species occur together. The results imply that these two congeneric species have different behaviour patterns which minimise interspecific competition where the species have sympatric distributions. C. finmarchicus has its younger development stages overlying the older stages in the water column. In C. helgolandicus the converse is true; i. e., the majority of the populations of Stage I and II copepodites of the first spring generations are found below the thermocline. It is also suggested that the different behaviour patterns lead to different feeding regimes and strategies.
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  • 10
    Electronic Resource
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    Springer
    Marine biology 87 (1985), S. 297-306 
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Zooplankton species diversity in the Celtic Sea in August 1982 was low; two species of copepod and two species of euphausiid accounted for 90 to 95% of the biomass sampled by a 280 μm-mesh net. Some 75% of the primary production was by phytoplankton smaller than 5 μm. The demands of both the macrozooplankton and the microzooplankton have been examined. If it is assumed that macrozooplankton cannot efficiently graze particles smaller than 5 μm, there was insufficient primary production to meet the demands of the copepods and euphausiids; however, there would have been sufficient if these animals could graze phytoplankton 5 to 1 μm. Ciliates were in competition with the macrozooplankton for phytoplankton and could not have been significant grazers of bacterial biomass. The majority of microflagellates were autotrophic; less than 10% of the population did not possess a chloroplast and were presumably heterotrophs. Bacterial production was low and was insufficient to meet the demands of the heterotrophic microflagellates, but there was sufficient production by the picophytoplankton to meet microflagellate requirements. The data do not appear to support the ideas of a significant flow of energy through the “microbial loop” in the Celtic Sea in August.
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