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  • 101
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    Springer
    Potato research 21 (1978), S. 1-8 
    ISSN: 1871-4528
    Keywords: growth ; yield ; rhizosphere ; Arran Banner ; Compagnon ; Bintje
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Description / Table of Contents: Zusammenfassung Im Herbst 1975, im Frühjahr und im Herbst 1976 wurden in Tripolis. Libyen, drei Versuche durchgeführt, um den Einfluss der Inokulation von Pflanzkartoffeln mitAzotobacter auf das Wachstum und den Ertrag von drei Kartoffelsorten (Arran Banner, Bintje und Compagnon) zu untersuchen. Nur bei der Sorte Arran Banner ergab sich eine Beeinflussung durch die Inokulation mitAzotobacter (Tabelle 1 und 3). Der Ertrag war in den drei Versuchen um 42.6% 17.4% bzw. 8.5% gesteigert. Die stärkste Reaktion ergab sich im ersten Versuch. bei dem niedrige Temperaturen und Bewölkung vorherrschten und die Wachstumsbedingungen für die Kartoffeln im allgemeinen ungünstig waren. Die Sorten Bintje und Compagnon zeigten keine signifikante Steigerung des Ertrages nach der Inokulation. Die Inokulation erhöhte die Stengellänge, hatte aber keinen signifikanten Einfluss auf die Stengelzahl pro Pflanze (Tabelle 2). Zählungen im Boden der Rhizosphäre zeigten. dass nach Inokulation des Pflanzgutes mitAzotobacter die Population in der Wurzelzone anstieg (Tabelle 4). Die Ertragssteigerung nach der Inokulation scheint durch eine Anreicherung vonAzotobacter in der Rhizosphäre intokulierter Pflanzen hervorgerufen zu sein.
    Abstract: Résumé Trois expérimentations ont été menées à Tripoli en Libie afin d'étudier l'effet de l'inoculation de tubercules de semence avecAzotobacter sp. sur la croissance et le rendement de 3 variétés de pomme de terre (Arran Banner, Bintje et Compagnon). Ces essais se sont déroulés durant l'automne 1975, le printemps et l'automne 1976. Il n'y a eu que la variété Arran Banner qui a répondu de manière conséquente à l'inoculationd'Azotobacter sp. (tableaux 1 et 3). L'augmentation de rendement a été respectivement de 42.6%, 17.4% et 8,5% dans les 3 expériences. La meilleure réponse a été obtenue dans la première expérimentation où des températures basses et des jours couverts ont dominé et où les conditions de végétation ont été généralement défavorables à la pomme de terre. Les variétés Bintje et Compagnon n'ont pas montré d'augmentation significative du rendement avec inoculation. L'inoculation parAzotobacter sp, augmente la longueur des tiges, mais n'a pas d'effet significatif sur le nombre de tiges par plante (tableau 2). Les comptagesd'Azotobacter sp. dans la rhizosphère ont indiqué que l'inoculation de la semence augmentait la populationd'Azotobacter au niveau de la zone racinaire (tableau 4). Cela est probablement dû au fait que l'augmentation du rendement grâce à l'inoculation résulte d'une meilleure adaptationd'Azotobacter sp. au niveau de la rhizosphère des plantes inoculées.
    Notes: Summary When the potato cultivars Arran Banner, Bintje, and Compagnon were inoculated withAzotobacter chroococcum in Libya, only Arran Banner responded significantly; plant growth was stimulated and the yield of marketable tubers increased by 8.5–42.6% above the untreated control. The very large yield increase in one season was associated with unfavourable growing conditions.
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  • 102
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    Potato research 37 (1994), S. 365-371 
    ISSN: 1871-4528
    Keywords: Solanum tuberosum L. ; multiplication ; micropropagation ; growth ; leaf removal ; tissue culture variation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Removing the leaves from single node potato cuttings in vitro allows propagules to be placed in culture vessels at increased densities with the intent of saving resources and space. Under light intensities of 22 wattsm−2, the removal of the subtending leaf resulted in fewer nodes, shorter plantlets, smaller leaf area, and lower fresh and dry weights of 4-week-old plantlets of cvs Atlantic, Kennebec, Russet Burbank and Shepody. Fewer nodes and reduced plantlet height may result in inefficient multiplication protocols because fewer propagules are available and shorter internodes make dissection more difficult. The coefficient of variation for the various growth parameters was greater when propagules lacked leaves, indicating that the variability of the plant material for propagation was increased. A reduction of vigour and growth was still evident when plantlets of cv. Shepody were grown for 6–8 weeks.
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  • 103
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    Potato research 24 (1981), S. 183-186 
    ISSN: 1871-4528
    Keywords: growth ; yield ; fertilizer mixes ; solubilization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The growth of potato plants and yield of tubers were poor in plots fertilized with rock phosphate alone but the addition of pyrites so improved its efficacy that it outyielded superphosphate in one season. A mixture of rock phosphate and superphosphate, in equal proportions on a P basis, was found to be 85–93% as effective as suerphosphate in increasing tuber yield.
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  • 104
    ISSN: 1871-4528
    Keywords: sprouts ; food reserves ; growth ; branching
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Description / Table of Contents: Zusammenfassung Der Verlauf des Keimwachstums wurde mit Knollen, die in verschiedenen Abständen vom keimenden Auge verletzt waren. untersucht. Die Inkubation erfolgte bei 12°C im Dunkeln in feuchtem ‘University of California’ Kompost. Obwohl die Steigerung des Keimtrockengewichtes mit der Zunahme an verfügbarem Knollensubstrat erhöht wurde, hatte die Verletzung noch einen zusätzlichen steigernden Einfluss, sowohl auf das Keimtrockengewicht als auch auf das Längenwachstum, das noch stärker gefördert wurde (Abb. 1). Wahrscheinlich sind sowohl das Ausmass der Verletzung als auch der Abstand der Verletzung vom Keim wichtig in bezug auf den Wachstumseinfluss. Der Einfluss der Grösse der Knollenstücke auf das Keimwachstum wurde ebenfalls untersucht. Zusätzlich zu der positiven Wirkung des steigenden Knollenstückgewichtes auf die Erhöhung des Keimtrockengewichtes zeigte sich noch ein weiterer Einfluss durch eine Vergrösserung des Knollenstückdurchmessers (Abb. 2). Wurden die Knollenstücke in Kompost gepflanzt, zeigte sich in bezug auf das Längenwachstum sowohl der Haupt-als auch der Seitentriebe ein umgekehrtes Verhältnis zum Frischgewicht der Knollenstücke, aber ein positives zum Durchmesser der Knollenstücke bei konstantem Frischgewicht (Abb. 3). Die Zahl der Seitentriebe pro Auge war mit dem Frischgewicht der Knollenstücke positiv korreliert.
    Abstract: Résumé La cinétique de la croissance du germe a été étudiée à l'aide de tubercules blessés à différentes distances des yeux, en maintenant des explantats à 12°C et à l'obscurité, dans un compost humide mis au point à l'Université de Californie. Bien que l'accumulation de matière sèche dans le germe ait été stimulée par l'augmentation du substrat assimilable provenant des gros explantats, la blessure a provoqué un effet cumulatif sur la teneur en matière sèche du germe et, de façon plus conséquente, sur son élongation (fig. 1). Il semble que l'importance de la blessure ainsi que sa distance par rapport à l'oeil jouent un rôle déterminant sur le dégré de réponse du germe. Des expériences ont également été réalisées sur des fragments de tubercules pour déterminer l'effet de la dimension de l'explantat sur la croissance du germe. En plus de l'effet positif sur la teneur en matière sèche, dû à l'augmentation du poids de l'explantat, on a observé un effet favorable lorsque le diamètre de ce dernier était plus élevé (fig. 2). Après plantation dans le compost, le taux d'élongation du germe principal et des germes ramifiés tendait à être inversé par rapport au poids frais de l'expplantat mais restait positif par rapport à son diamètre, à poids frais égal (fig. 3). Le nombre de ramifications par oeil était en relation directe avec le poinds frais de l'explantat.
    Notes: Summary Sprout dry weight accumulation was stimulated by an increase in the amount of tuber substrate available. Wounding had an additional promotory effect on both dry weight accumulation and extension growth. Sprout dry weight accumulation from tuber cores of the same fresh weight was enhanced by an increase in the diameter of the core when samples were planted either in perlite or UC compost. In compost, elongation rates of both main and branch sprouts were inversely related to core fresh weight but positively related to core diameter when fresh weight was kept constant. The number of branch sprouts per eye was positively related to core fresh weight.
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  • 105
    ISSN: 1871-4528
    Keywords: Solanum tuberosum L. ; temperature stress ; growth ; nutrient deficiency ; tuber analysis ; tuber size ; glasshouse ; growth room
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary To determine calcium fertility and high temperature effects on internal brown spot development in potato, cv. Russet Burbank plants were fertilised with Hoagland's nutrient solution with or without calcium. Prevalence and severity of internal brown spot were greatest in tubers receiving no calcium fertilisation during growth. Internal brown spot was evident as early as tuber initiation. A high growth medium temperature (32°C) at tuber maturity with a lack of calcium increased internal brown spot incidence and severity. No tubers subjected to the high temperature and fertilised with calcium developed internal brown spot. Peel calcium concentration of tubers receiving no calcium fertilisation was lower (0.5–0.8 g/kg) than tubers receiving calcium (1.2–1.9 g/kg). Medullary tissue calcium concentration was similar under both calcium regimes. Calcium availability during early tuber growth was an influential factor in internal brown spot development, however high temperature effects may not be discounted in exacerbating the disorder.
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  • 106
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    Plant systematics and evolution 165 (1989), S. 227-237 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Eucalyptus ; Eudesmieae ; Floral morphology ; calyx ; corolla ; operculum ; growth ; allometry ; convergence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In theEudesmieae B eucalypts and inEucalyptus caesia, the perianth of the mature flower consists of a single, anatomically continuous, opercular structure that is crowned by the tips of the original free and separate calycine and corolline whorls. Ontogenetic and comparative evidence supports the hypothesis that this operculum is mostly corolline in composition, and that the calycine parts have been elevated distally onto the dorsal surface. In theEudesmieae B eucalypts this condition appears to be due to precocious initiation of the corolline primordia, followed by expansion and continuity of their growth centres which incorporates the areas at or below the base of the still differentiating calycine whorl. InEucalyptus caesia the corolline primordia are not precocious, but a similar situation is effected by a seemingly retarded increase in receptacle diameter relative to lateral expansion of the corolline growth centre(s). In these two examples the same final perianth form apparently derives from two different sets of growth processes which, nonetheless, result in the same allometric relationships within the developing flower. Although identical at maturity, the operculum form in these two taxa is best described in terms of convergence, rather than homology.
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  • 107
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    Plant systematics and evolution 196 (1995), S. 195-206 
    ISSN: 1615-6110
    Keywords: Pteridophyta ; Dryopteridaceae ; Dryopteris filix-mas ; Clonal gametophytes ; growth ; reproduction ; genetic and environmental effects ; phenotypic plasticity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Artificially formed clonal gametophytes ofDryopteris filix-mas (L.)Schott were able to grow and reproduce, although growth rates, proportions of hermaphrodites and reproductive efforts were low. Variable density and nutrient levels appeared to affect gametophytic life histories and they continued to influence the viability of the developing sporophyte generation. Differences between populations and sporophytes were discovered in life histories. Hermaphroditic gametophytes were considerably larger and possessed higher viability than did males. Clear differences between clones in the level of phenotypic plasticity in gametophyte size were observed. No neighbor effect on gametophyte sex expression was detected with the densities and nutrient levels used.
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  • 108
    ISSN: 1608-3237
    Keywords: poly-β-hydroxybutyric acid ; Yersinia pseudotuberculosis ; Listeria monocytogenes ; temperature ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A comparative investigation of the intracellular content of poly-β-hydroxybutyric acid showed that Yersinia pseudotuberculosis strains accumulated, on the average, lower amounts of this reserve substance than Listeria monocytogenes strains. The intracellular pool of poly-β-hydroxybutyric acid was responsible for the growth of the bacteria at low temperatures (4–6°C) in the absence of any exogenous carbon and energy source.
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  • 109
    ISSN: 1608-3407
    Keywords: Scenedesmus quadricauda ; growth ; cell size ; photosynthetic activity ; imazalil sulfate ; three-phase dose response
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Three-phase dose responses of biological systems of different levels of organization are often called “paradoxical” because the biological effects are clearly manifested under low- and high-intensity treatments, but are absent during moderate-strength treatments. In this work, we found anomalous changes in the cell number of a green alga Scenedesmus quadricauda (Turp.) Breb. grown in the presence of the fungicide imazalil sulfate. At low imazalil concentrations (2.5 × 10–9–2.5 × 10–6 M), the slow increase in the cell number as compared to an untreated culture was not related to cell death. As seen by the dynamics of the population structure and cell functional characteristics (photosynthesis, thermal stability of photosynthetic membranes, etc.), the decrease in the growth rate at low concentrations of imazalil (2–10 × 10–9 M) was due to a long-term arrest of cell division in a fraction of the cell population rather than to a decrease in the rate of division. The absence of a toxic effect or even a slight stimulation of culture growth at moderate concentrations (0.05–1.25 × 10–6 M) was due to the resumption of cell division after a temporal cessation. At these concentrations, imazalil induced cell stress and adaptive elevation of cell tolerance to the fungicide (acclimation). Cell death was observed only at a high fungicide content in the medium (6.25 × 10–6 and higher). Thus, the three-phase (bimodal) dose response corresponds to two regimes (steady-states) of cell functioning which differ in cell sensitivity to external stimuli. The low-sensitivity state, which is characteristic of cells that have experienced stress, is likely to be the state known as “hormesis.”
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  • 110
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    Aquatic ecology 19 (1985), S. 179-181 
    ISSN: 1573-5125
    Keywords: zebra mussels ; polystyrene ; settlement ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The growth of settled and metamorphosed larvae of the zebra mussel (Dreissena polymorpha) is clearly retarded when polystyrene plates are used as a substrate compared with the growth of those forms attached to PVC plates. Possibly, low molecular weight compounds are released into the aquatic environment by the polystyrene and these materials may have a strongly adverse effect upon the growth of young zebra mussels. There is no difference in colonization of young mussels between PVC and polystyrene plates if these plates are sufficiently overgrown with bacteria and algae.
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  • 111
    ISSN: 1573-5176
    Keywords: Debromolaurinterol ; growth ; Laurencia ; laurinterol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The growth of Laurencia okamurae and the content of laurinterol and debromolaurinterol were influenced by various factors. Temperature influenced growth raere te with a maximum at 25°C, regardless of daylength. Maturity depended on temperature rather than daylength; the plants grew without maturing at 15°C, while the plants matured within two weeks at 25°C. The plants were able to grow at salinities of 14–50‰ with maximum growth at 26‰. The salinities growth rash;50‰te reduced with decreasing concentration of nitrate below 1.2 × 10-3 M, and of total phosphate below 7.5× 10-8 M. Bromide concentration had no effect on growth, and the plants grew without bromide. Variation in temperature between 15–25°C and daylength produced no obvious change in laurinterol and debromolaurinterol contents. On the other hand, an increase in salinity led to an increase for both. The plants cultured in a completely artificial medium, modified ASP12NTA, showed a marked drop in their content of these metabolites. An increase in concentrations of nitrate, total phosphate or bromide did not restore the content.
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  • 112
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    Journal of applied phycology 10 (1998), S. 547-554 
    ISSN: 1573-5176
    Keywords: herbicide ; green alga ; growth ; nutrients ; photosynthesis ; it Protosiphon botryoides ; respiration ; Thiobencarb
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effects of the herbicide thiobencarb (Saturn) were tested on the growth and physiology of the chlorophyte Protosiphon botryoides isolated from an Egyptian paddy. Assays were conducted using 16-day batch cultures. Chlorophyll and dry weight biomass yields were significantly reduced at 2–3 mg L-1 thiobencarb, and dark respiration increased and protein decreased significantly at 3 mg L-1. Reductions in exponential specific growth rate (μ) were generally small, but in some cases significant. Thiobencarb also slightly, but significantly, reduced the 77 K fluorescence parameter Fv/Fm, an indicator of maximum photosynthetic efficiency. No consistent dose-dependent changes occurred in chlorophyll per unit dry weight, total carbohydrate or gross photosynthetic capacity. Whereas half of the added thiobencarb was recovered from control (uninoculated) medium, it was largely absent from cells and culture medium after sixteen days, indicating biodegradation by the alga or associated bacteria. P. botryoides recovered fully within sixteen days following subculture in thiobencarb-free medium. Independently varying phosphate and nitrate nine-fold had no clear effect on the sensitivity of P. botryoides to thiobencarb.
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  • 113
    ISSN: 1573-5176
    Keywords: agar ; Gracilaria tenuistipitata ; growth ; salinity ; seawater pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Acclimation responses of the red alga Gracilaria tenuistipitata var. liui collected on the northwest coast of Philippines were determined in laboratory setups and outdoor cultivation tanks in Haifa, Israel. Growth under laboratory conditions was influenced by all three variables studied, namely, temperature (20 or 30 °C), salinity (20, 30 or39‰) and seawater pH (6.5, 7.0, 8.0 or ≥ 9.0). In 250 mL flasks lacking pH control growth was influenced by temperature only at 20 ‰, whereas at 39 ‰, growth rates were similar at 20 or 30 °C. In 500 mL cylinders in which pH was controlled, growth rates were significantly different at a pH of 6.5 and 7.0 for all salinities, with maximal rates occurring in 39 ‰. At pH 8.0, and above, growth rates between salinities were similar and reduced to approximately 50% at a pH of 9.0 compared to rates at a pH of 6.5. Photosynthesis responses generally resembled growth responses both, in 250 mL and 500 mL cultures. In 40-L outdoor tanks, weekly growth and agar yields were apparently enhanced by increasing light intensities (up to full sunlight) and nutrient concentrations (up to 0.2 mM PO3 2- and 2.0 mM NH4 +), and rates averaged four times higher than rates determined in the smaller flask cultures. This study shows broad salinity tolerance of G. tenuistipitata var. liui and its ability to sustain growth rates that are among the highest measured for Gracilaria spp. in outdoor cultures.
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  • 114
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    Journal of applied phycology 12 (2000), S. 185-189 
    ISSN: 1573-5176
    Keywords: blue-green alga ; cyanobacterium ; carbon dioxide ; culture ; growth ; Nostocflagelliforme ; rehydration, watering
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The terrestrial blue-green alga (cyanobacterium), Nostoc flagelliforme, was cultured in air at variouslevels of CO2, light and watering to see theireffects on its growth. The alga showed the highestrelative growth rate at the conditions of highCO2 (1500 ppm), high light regime (219–414μmol m-2s-1) and twice daily watering,but the lowest rate at the conditions of low light(58–114 μmol m-2s-1) and daily twicewatering. Increased watering had little effect ongrowth rate at 350 ppm CO2, but increased byabout 70% at 1500ppm CO2 under high lightconditions. It was concluded that enriched CO2could enhance the growth of N. flagelliformewhen sufficient light and water was supplied.
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  • 115
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    Aquatic ecology 28 (1994), S. 453-458 
    ISSN: 1573-5125
    Keywords: filter-feeding ; energy cost ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract An overview of recent findings concerning filter-feeding inNereis diversicolor is given. It has been discovered that the facultative filter-feederN. diversicolor may meet its metabolic requirements on a pure diet of phytoplankton, just as a typical obligate filter-feeder. Consequently, this worm is likely to be a hitherto undervalued key organism in the control of phytoplankton production in many shallow brackish water areas.
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  • 116
    ISSN: 1573-5125
    Keywords: growth ; Azolla ; eutrophication ; mercury ; India
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The growth ofAzolla was stimulated in different water bodies in Burdwan. It depended on the PO4−P contents of the media. Biomass, chlorophyll and tissue phosphorus content ofAzolla were positively correlated with PO4−P of the different water bodies while chlorophyll content of the fern was positively correlated with conductivity. We concluded that the water bodies of Burdwan can be utilised as sites for large scale multiplication ofAzolla for fertilization purposes in rice cultivation, despite the presence of mercury.
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  • 117
    ISSN: 1573-5176
    Keywords: Porphyra columbina ; growth ; reproduction ; chemical composition ; seasonality ; Rhodophyceae ; New Zealand
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Changes in biomass and chemical composition, and the reproductive phenology ofPorphyra columbina Mont. were monitored at three sites in southern New Zealand over two growing seasons. Both temporal and spatial variations were found. Seasonal changes in biomass and chemical components were correlated with seawater nitrate concentrations and temperature. The summer decline in biomass was a result of the onset of unsuitable environmental conditions and the release of reproductive tissue. Under more suitable conditions, the decline in biomass was delayed. There was an inverse relationship between vegetative growth and reproduction. Reproductive plants first appeared in August at a time of increasing temperature, irradiance and daylength. Only larger plants which were mainly found in subsites low on the shore became reproductive. Plants sampled from high subsites had a shorter growth season, were generally smaller, had lower nitrogen and pigment content and were non-reproductive.
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  • 118
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    Journal of applied phycology 3 (1991), S. 61-82 
    ISSN: 1573-5176
    Keywords: Furcellaria ; morphology ; life history ; chemical constituents ; ecophysiology ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Information on the commercially utilized marine red alga Furcellaria lumbricalis is summarized from published sources. Biological aspects under discussion include: nomenclature, taxonomy, morphology, development and life history, distribution, phenology, ecophysiology, growth and resource management. A brief history of the utilization of this species, and an account of its chemical constituents including the hydrocolloid furcellaran are also presented.
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  • 119
    ISSN: 1573-5176
    Keywords: CO2 ; growth ; pH ; photosynthesis ; Porphyra yezoensis ; red alga
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Leafy thalli of the red algaPorphyra yezoensis Ueda, initiated from conchospores released from free-living conchocelis, were cultured using aeration with high CO2. It was found that the higher the CO2 concentration, the faster the growth of the thalli. Aeration with elevated CO2 lowered pH in dark, but raised pH remarkably in light with the thalli, because the photosynthetic conversion of HCO 3 − to OH− and CO2 proceeded much faster than the dissociation of hydrated CO2 releasing H+. Photosynthesis of the alga was found to be enhanced in the seawater of elevated dissolved inorganic carbon (DIC, CO2 + HCO 3 − + CO 3 − ). It is concluded that the increased pH in the light resulted in the increase of DIC in the culture media, thus enhancing photosynthesis and growth. The relevance of the results to removal of atmospheric CO2 by marine algae is discussed.
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  • 120
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    Journal of applied phycology 3 (1991), S. 319-327 
    ISSN: 1573-5176
    Keywords: Dunaliella viridis ; growth ; salinity ; temperature ; nitrogen concentration ; batch culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The growth of a strain ofD. viridis has been studied in batch culture under different combinations of temperature, salinity and nitrogen concentrations. Changes in these variables have a significant effect on cell division, biomass production, cell volume and pigment yield. This strain grows optimally at 1 M NaCl and 30 °C. Increasing salinity up to 4 M NaCl leads to a significant decrease of cell division rate and maximal population; growth at lower temperature decreases the rate of division of the cells but increases maximal cell density. Pigment yield decreases with increasing salinity and increases with increasing temperature. Nitrogen concentration has a large effect on total cell biomass and pigment production, but not on cell division rate. Saturation of growth occurs at 5 mM NO 3 − ; higher concentration (e.g. 10 mM) leads to a decrease of maximal cell density and photosynthetic pigment content.
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  • 121
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    Journal of applied phycology 6 (1994), S. 41-44 
    ISSN: 1573-5176
    Keywords: Prorocentrum ; semi-continuous culture ; okadaic acid ; growth ; suspension culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Clonal cultures ofProrocentrum hoffmannianum Faust (clone 882a) were grown under optimal environmental conditions for maximal okadaic acid production. The environmental conditions of 25 °C and 86 µmol photon m-2 s-1 were used to cultivateP. hoffmannianum in a semi-continuous 36-L culture vessel with continuous cell suspension and pH control. Using these conditions, a 3-fold increase in harvestable biomass and okadaic acid content was observed when compared to batch culture techniques.
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  • 122
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    Journal of applied phycology 9 (1997), S. 19-24 
    ISSN: 1573-5176
    Keywords: Chaetoceros ; growth ; neutral lipid ; total lipid ; nitrogen deprivation ; Nile Red
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Chaetoceros muelleri (Schütt) was cultured on a thermal gradient plate, subjected to two media types with a range of specific conductances, and evaluated for growth and neutral lipid accumulation. Growth was measured directly by daily changes in cell numbers and indirectly by changes in optical density at 750 nm. C. muelleri exhibited a growth rate of at least two doublings day-1 over broad temperature (20 to 35 °C) and conductance ranges (10 to over 60 mS cm-1) and the optimum growth rate approached 4.0 doublings day-1 at 30 °C and a conductance of 25 mS cm-1. Intracellular neutral lipid storage was evaluated with fluorometry and epifluorescent microscopy using the fluorochrome Nile Red. Gravimetric analysis revealed a total lipid content in nitrogen-depleted cultures of C. muelleri of over 400 mg L-1, five to seven times that observed in nitrogen-replete cultures. Based on its high growth rate, tolerance to a broad range of temperatures and specific conductances, and large quantity of intracellular lipid, C. muelleri may have potential for exploitation as a renewable precursor to liquid fuels or as a lipid source.
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  • 123
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    Journal of applied phycology 9 (1997), S. 437-444 
    ISSN: 1573-5176
    Keywords: Haematococcus pluvialis ; experimental design ; optimization ; culture medium ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A central composite rotatable design was used to examine the effects of five components of the medium on the growth of Haematococcus pluvialis in batch culture. The medium components considered were: sodium acetate,potassium nitrate, major elements, trace elements and vitamins. Within the range of the concentrations tested, a moderate concentration of the major elements significantly enhanced algal growth, both in terms of specific growth rate and cell dry weight, whereas the vitamins had no significant effect. Based on the response surface contour plots and the results of numerical analyses, the optimal nutrient concentrations for growth in terms of specific growth rate were 0.51 g L-1 sodium acetate, 0.25 g L-1 potassium nitrate, 0.63 mL L-1 of the major element stock solution and 0.2 mL L-1 of the trace element stock solution. The optimal nutrient concentrations for biomass production were 1.64 g L-1 sodium acetate, 0.37 g L-1potassium nitrate, 2.52 mL L-1 of the major element stock solution and 0.03 mL L-1 of the trace element stock solution.
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  • 124
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    Journal of applied phycology 9 (1997), S. 551-558 
    ISSN: 1573-5176
    Keywords: Spirulina ; Arthrospira ; growth ; salinity ; quantum yield ; nutrient status ; Chitu ; Ethiopia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Spirulina platensis (=Arthrospira fusiformis) was isolated from Lake Chitu, a soda crater lake in the Ethiopian Rift Valley, where it formsa dense and almost unialgal population. Growth experiments were run in turbidostats under constant light, to assess growth response and tolerance to salinity, as well as to the component anions. Salinity was tested over the range 13–88 g L-1 using additions of NaHCO3, NaCl or Na2SO4. A maximum specific growth rate (µmax d-1) of 2.14 was achieved at the lowest salinity, but quantum yield (Φ%) was highest between 33 to 51 g L-1. Increasing salinity of the medium reduced the specific growth rate (µ) to a minimum of 0.33 d-1, and Φ to 〈 0.5%. Growth response in terms of µ and Φ was best in HCO 3 - , less in Cl-, and least in SO 4 2- series. Cultures showed obvious differences in cellular morphology, pigment, nitrogen and phosphorus contents in response to treatment with the different anions. Results indicate that the species has a wide range of tolerance to salinity from NaHCO3. Some degree of tolerance is also shown to high concentrations of Cl- and SO 4 2 , but with an overall lower performance of cells in terms of growth rate, light utilization efficiency, and nutrient status to cells grown in high HCO 3 - concentrations and the same levels of salinity and light.
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  • 125
    ISSN: 1573-5125
    Keywords: eutrophication ; feeding ; growth ; Mytilus edulis ; validation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract EMMY is an ecophysiological model of the growth and reproduction of a single mussel (Mytilus edulis L.). It contains feedback loops in the uptake and metabolism of food and in the partitioning of carbon and nitrogen to the internal state variables somatic tissue, storage, organic shell matrix and gametes. In this paper EMMY is used to simulate individual mussel growth in a series of mesocosm experiments with different inorganic nutrient loads (N and P). The experiments explore the impact of eutrophication reduction scenarios on mussel growth under defined and controlled conditions. In earlier studies EMMY was calibrated using expert knowledge on growth and reproduction during a period of 5 years. The resulting calibrated model was validated for system inputs and observations of three ecosystems with significantly different food and silt concentrations. EMMY reproduced the mussel growth sufficiently accurate in ecosystems with moderate or high food concentrations. In this study EMMY was adapted in order to cope with low food concentrations, then recalibrated (using the original calibration data and procedure) and applied without further calibration to 3 replicated mesocosm experiments. The EMMY simulations in this study show the ecophysiological response of mussels to different food (phytoplankton and detritus) concentrations. It is concluded that the mussels can adapt to significantly reduced food concentrations, due to inorganic nutrient load reduction, and still maintain growth.
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  • 126
    ISSN: 1573-5176
    Keywords: cyanobacteria ; blue-green algae ; biosynthesis ; growth ; gamma linolenic acid
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    Topics: Biology
    Notes: Abstract The total lipid and fatty acid content ofSpirulina platensis UTEX 1928 was 7.2 and 2.2% respectively of cellular dry weight under controlled conditions supporting high growth rates. With increases in irradiance from 170 to 870 μmol photon m−2 s−1, growth rate increased, total lipid decreased, and fatty acid composition was unaffected. At 1411 μmol photon m−2 s−1, total lipid increased slightly and percent composition of the fatty acid gamma linolenic acid increased. Growth and total lipid content ofS. platensis were affected by changes in growth temperature from 25 to 38 °C. With increased growth rate, total lipid content increased. This suggests that the storage of carbon increases at temperatures supporting high growth rates. The degree of saturation increased with temperature. Although the percent composition of gamma linolenic acid was higher at lower growth temperature, production was still primarily a function of growth rate. The effect of temperature on fatty acid content and degree of saturation was of secondary importance. Nitrogen starvation increased total lipid content but decreased fatty acid content as a percentage of dry weight; composition of the fatty acids was unaffected. N-starvation appeared to suspend synthesis of long chain fatty acids inS. platensis, suggesting that some other compound stores fixed carbon when nitrogen is limiting. It was concluded that fatty acid production inS. platensis is maximized by optimizing culture conditions for growth.
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  • 127
    ISSN: 1573-5176
    Keywords: fluorescence ; growth ; pigments ; phytoplankton ; population dynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In applied water ecology several methods for estimating the biomass or activity of phytoplankton depend on the proportion of accessory pigments (xanthophylls) to chlorophyll a. Therefore, changes in pigmentation during growth and stationary phase were investigated in four different species (Amphidinium klebsii, Euglena gracilis, Prymnesium parvum, Cryptomonas ovata) typical representatives of the major algal groups. The ratios of the different xanthophylls to chlorophyll a depended not only on the growth phase, but also on the species. InAmphidinium andEuglena, the ratio of xanthophylls to chlorophyll rises continuously during the growth phase and declined during the stationary phase. InPrymnesium, quantitative pigmentation was found to be nearly independent of the growth phase. InCryptomonas, however, this ratio was relatively constant during growth, but increased in the stationary phase. In contrast to higher plants, in which the breakdown of chlorophylls occurs before that of the xanthophylls, in three of the species both pigment classes were reduced in parallel when the cultures were in the stationary phase. AgingCryptomonas, however, exhibited a pigment breakdown pattern similar to higher plants. The use of these findings for the widely applied biomass determination by chlorophyll fluorescence and for other pigment-based methods is discussed.
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  • 128
    ISSN: 1573-5176
    Keywords: fluorescence ; growth ; pigments ; phytoplankton ; population dynamics
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    Topics: Biology
    Notes: Abstract In applied water ecology several methods for estimating the biomass or activity of phytoplankton depend on the proportion of accessory pigments (xanthophylls) to chlorophyll a. Therefore, changes in pigmentation during growth and stationary phase were investigated in four different species (Amphidinium klebsii, Euglena gracilis, Prymnesium parvum, Cryptomonas ovata) typical representatives of the major algal groups. The ratios of the different xanthophylls to chlorophyll a depended not only on the growth phase, but also on the species. InAmphidinium andEuglena, the ratio of xanthophylls to chlorophyll rises continuously during the growth phase and declined during the stationary phase. InPrymnesium, quantitative pigmentation was found to be nearly independent of the growth phase. InCryptomonas, however, this ratio was relatively constant during growth, but increased in the stationary phase. In contrast to higher plants, in which the breakdown of chlorophylls occurs before that of the xanthophylls, in three of the species both pigment classes were reduced in parallel when the cultures were in the stationary phase. AgingCryptomonas, however, exhibited a pigment breakdown pattern similar to higher plants. The use of these findings for the widely applied biomass determination by chlorophyll fluorescence and for other pigment-based methods is discussed.
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  • 129
    ISSN: 1573-5176
    Keywords: integrated culture ; kelp ; salmon ; growth ; economics ; nutrient uptake
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    Topics: Biology
    Notes: Abstract The technical and economical feasibility of farmingLaminaria saccharina for a food base product near a salmon sea cage farm was evaluated. Suitability of kelp for nutrient removal was also analyzed. A computer model of a conceptualized system was developed in order to make the assessments. Kelp growth was modelled as a linear function of temperature and background dissolved inorganic nitrogen concentration, and it was partially experimentally validated. Based on model simulations, aLaminaria farm containing 10,60 m ropes on each end of a salmon sea cage farm is fertilized by the salmon farm and yields annually 1600 kg of dried kelp. The payback period for the initial investment of $61 × 103 is 6 years after which an annual net profit of 20 × 103 Canadian dollars ($16.68 × 103 US) can be achieved. The net present worth of the kelp farm was positive for a rate of return up to 25%. Kelp production on multiple salmon farms or at a higher kelp density could increase the overall revenue. The kelp farm does not appreciably affect background nutrient or oxygen levels. With a few modifications in the model,Nereocystis andMacrocystis farming can be substituted and evaluated for feasibility and nutrient removal efficiency.
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  • 130
    ISSN: 1573-5176
    Keywords: Haematococcus pluvialis ; ethylene ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In the freshwater ChlorophyceaeHaematococcus pluvialis, precursors of ethylene biosynthesis cycle are the same as those of higher plants: L-methionine → S-adenosylmethionine → 1-aminocyclopropane-1-carboxylic acid → ethylene. However, the enzymatic complex of the last step of ethylene synthesis-ACCoxidase-differs from that of higher plants. It is stimulated by Co2+ (at least 10-5 M), Mn2+ (at least 10-6 M) and Ag2+ (at least 10-4 M), inhibited by Cu2+ (at least 10-5 M) and not affected by Zn2+, Fe2+ or Mg2+. ACCoxidase is also inhibited by salicylhydroxamic acid and by dark. Ethylene production is more important in young, mobile, green cells in active growth phase than in old, encysted and red cells in stationary growth phase. No peaks in ethylene production or respiration were observed during batch culture, as opposed to the situation with climacteric fruits.
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  • 131
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    Journal of applied phycology 4 (1992), S. 339-345 
    ISSN: 1573-5176
    Keywords: temperature ; growth ; red algae mariculture ; Brazil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Data are presented on temperature responses, based onin vitro growth performance, of eight species of colloid-producing red algae; these include the five most important commercial species of agarophytes in South America. The temperature optima do not conform strictly to geographic distribution, and intolerance to high temperature is not the factor that controls the spreading of temperate species ofGracilaria to warmer areas. WithinPterocladia capillacea (Gmelin) Bornet et Thuret, populations from two distinct localities had different responses to temperature optima. Data suggest that the disjunct distribution of this species in the American Atlantic is due to its poor performance at temperatures above 26 °C. The fastest maximum growth rate was observed inHypnea cornuta (Lamouroux) J. Agardh (doubling time 2.8 d), and the slowest inP. capillacea from Cabo Frio (doubling time 50.0 d). All the species studied, including the valuable Chilean and Argentinean species ofGracilaria, could tolerate the temperature regimes of the Brazilian waters.
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  • 132
    ISSN: 1573-5176
    Keywords: Gracilaria chilensis ; growth ; nutrient pulses ; epiphyte abundance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of nutrient pulse concentration and frequency onGracilaria chilensis Bird, McLachlanet O Oliveira growth and epiphyte abundace was investigated for plants grown in an indoor culture facility. The frequency of nutrient pulses (which ranged from 1 pulse to 4 pulses per 14 days) had a strong influence on plant growth, while pulse concentration (from 72 to 143 µM as ammonium) had a lesser influence. Growth became a function of total N flux only when plants received nutrient pulses at least twice per 14 days. Both pulse frequency and pulse concentration affected the abundance of epiphytic algae found attached toGracilaria thalli, but pulse frequency was the more significant of the two factors. Their effects could be combined into the single factor, total N flux. Both reasonableG. chilensis growth and low levels of epiphytes were achieved under these conditions (20 °C, 25 µ mol photon m−2 s−1 PAR) if ammonium was pulsed at relatively high concentrations (up to 150 µM) once every 7 days into otherwise nitrogen-depleted seawater.
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  • 133
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    Journal of applied phycology 5 (1993), S. 547-549 
    ISSN: 1573-5176
    Keywords: Trentepohlia odorata ; Dunaliella bardawil ; light intensity ; nitrogen ; growth ; carotenogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract AxenicTrentepohlia odorata was cultured at three different NH4Cl levels (3.5 × 10−2, 3.5 × 10−3, 3.5 × 10−4 M) and three different light intensities (48, 76, 122 µmol m−2 s−1). Chloride had no effect on growth over this range of concentration. High light intensity and high NH4Cl concentration enhanced the specific growth rate. The carotenoid content increased under a combination of high light intensity and low N concentration. WhenD. bardawil was exposed to the same combination of growth conditions, there was an increase in its carotenoid content. The light saturation and the light inhibition constants (K s andK i, respectively) for growth, and the saturation constant (K m) for NH4Cl were determined. TheK s andK i values were higher inT. odorata (66.7 and〉 122 σmol m−2 s−1, respectively) than inD. bardawil (5.1 and 14.7 µmol m−2 s−1, respectively). TheK m value determined at 122 µmol m−2 s−1, however, was lower inT. odorata (0.048 µM) than inD. bardawil (0.062 µM).
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  • 134
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    Journal of applied phycology 5 (1993), S. 563-571 
    ISSN: 1573-5176
    Keywords: CO2 ; Gracilaria ; growth ; nitrate ; 18O2 ; photorespiration ; photosynthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The influence of elevated CO2 concentrations on growth and photosynthesis ofGracilaria sp. andG. chilensis was investigated in order to procure information on the effective utilization of CO2. Growth of both was enhanced by CO2 enrichment (air + 650 ppm CO2, air + 1250 ppm CO2, the enhancement being greater inGracilaria sp. Both species increased uptake of NO3 − with CO2 enrichment. Photosynthetic inorganic carbon uptake was depressed inG. chilensis by pre-culture (15 days) with CO2 enrichment, but little affected inGracilaria sp. Mass spectrometric analysis showed that O2 uptake was higher in the light than in the dark for both species and in both cases was higher inGracilaria sp. The higher growth enhancement inGracilaria sp. was attributed to greater depression of photorespiration by the enrichment of CO2 in culture.
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  • 135
    ISSN: 1573-5176
    Keywords: Dunaliella viridis ; subsidiary energy quantification ; growth ; carotenoids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract An account is given of the influence of different levels of mechanical energy, in the form of bubbling, on the growth of the microalgaDunaliella viridis when other variables (e.g. temperature, nutrient supply, photon fluence) do not change. The extra energy was quantified accurately through the application of the classical equations of mass and energy conservation providing a method for the calculation of the energy efficiency of primary production related to the total energy input, in which photon fluence was found to be the most important. The specific growth rate (μ) of the population vs the input of auxiliary energy fits to a second order polynomial function with a maximum growth rate at 0.63 W m−2. The increase of maximal cell density follows a hyperbolic saturation kinetics, with saturation at those same values of extra energy. Both primary production and the efficiency of energy transformation inD. viridis vs the variation of total energy input fit to hyperbolic functions, reaching a maximum efficiency for primary production of 0.85%.
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  • 136
    ISSN: 1573-5176
    Keywords: deep seawater ; micro-algae ; growth ; yield
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Deep seawater (DSW; seawater under the euphotic layer), obtained from Deep Seawater Laboratory in Muroto, Japan, was applied to the culture ofDunaliella tertiolecta, D. salina, Nannochloropsis oculata, N. salina, Porphyridium cruentum, Tetraselmis tetrahele, andChaetoceros ceratosporum. DSW supported the exponential growth of every species. The growth yields were at 14.7 (±2.3 SD) mg dry weight per liter, and could be heightened by the addition of nitrate to DSW.
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  • 137
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    Journal of applied phycology 8 (1996), S. 421-430 
    ISSN: 1573-5176
    Keywords: Gracilaria gracilis ; suspended cultivation ; vegetative propagation ; South Africa ; yield ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Rope rafts were used to evaluate the growth of localGracilaria gracilis at Saldanha Bay, on the west coast of South Africa, over four years. The plants were grown on horizontally-suspended ropes or netting lines. Relative Growth Rates (RGR) of plants on ropes with low stocking weights often exceeded 10% d−1 in (austral) summer, and fell to between 6 and 7.5% d−1 in winter. Commercial-style lines of plastic netting stocked at 400 g m−1 and placed 0.75 m apart yielded a mean of about 2 kg m−2 30 d−1, with a mean RGR of about 5% d−1 over a two-year period. Various methods of improving yields were tested, including attaching floats to individual lines and optimising stocking weight. In Saldanha Bay in late summer, warm, oligotrophic water can severely reduce growth. Growth was optimised by growing the plants as close as possible to the surface (0.2 m), where water motion, and by implication, nutrient uptake, are higher. Agar content and gel strength generally remained high all year round. The potential for commercial production is evaluated in the light of these results.
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  • 138
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    International journal of anthropology 8 (1993), S. 1-9 
    ISSN: 1824-3096
    Keywords: growth ; anthropometric characteristics ; sexual dimorphism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A mixed longitudinal study of growth and development has been conducted, centering on an analysis of differences based on sex between the ages of 8 and 18 years for a series of 12 anthropometric indicators. The sample consisted of 50 girls and 63 boys. Proceeding from the specific differences, the variables can be divided into four groups with identical structures of differences. The first group comprises measurements of body height, body mass, shoulder width and pelvic span, all of which have higher values in boys between 8 and 10 and between 14 and 18. Between the ages of 11 and 13 girls are taller, heavier, with broader shoulders and pelvises. The second group covers measurements of subcutaneous fat. which are higher for girls throughout the period under review. The third group of indicators comprises the diameters of the joints of the extremities, i.e. of elbows and knees. Throughout the period under observation, these measurements are higher in boys, with the absolute differences between the sexes being the same at the age of 8 and ten years later. The fourth group consists of circumferences measurements of the extremities. It was found that calf circumferences manifested a specific inversion of the curves between 14 and 15, with girls showing a larger calf circumference up to the age of 14, and boys from the age of 15. The effect of earlier onset of puberty in girls was found to be reflected only on the inversion of the curve flow of the variables from the first group.
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  • 139
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    International journal of anthropology 1 (1986), S. 107-112 
    ISSN: 1824-3096
    Keywords: growth ; shape and size ; Spanish population
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    Topics: Biology
    Notes: Abstract In this work the analogies and differences in shape and size between a rural school population (6–14 aged) of the Lozoya-Somosierra region (Madrid) and several recent and past Spanish populations from different environments have been studied. The results show the growth trend as well as the influences of ecological and socioeconomical factors.
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  • 140
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    International journal of anthropology 6 (1991), S. 257-265 
    ISSN: 1824-3096
    Keywords: Children somatotyping ; Spanish population ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Using the Heath-Carter (1972) method modified byHebbelinck et al. (1973), the somatotypes ina Spanish school-age population were determined. The study shows an evolution in the components of the somatotype with age, and a distribution of somatoplots in the somatochart which presnts peculiar characteristics in both sexes.
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  • 141
    ISSN: 1573-0778
    Keywords: batch culture ; conditioned medium ; growth ; hybridoma ; inoculum ; protein productivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Apart from gas concentrations, temperature, and pH, generally only the initial conditions can be manipulated in batch culture. Inoculum size and initial conditioned medium concentration represent two important considerations for optimal batch production. Two hybridoma cell lines were used to assess the impact of these initial conditions on population growth and monoclonal antibody productivity in suspension batch culture. Varying initial cell concentration over the range of 1.0 × 105 cells mL-1 to 3.0 × 105 cells mL-1 did not affect maximum product titre or maximum volumetric cell-hours attained. Initial percent of conditioned medium up to 40 percent strongly impacted on population growth and productivity, with initial levels of 30 to 40% conditioned medium reducing or eliminating lag phase and increasing average viable cell density. However, specific productivity and product titre declined with increasing initial percent conditioned medium, even on a per volume of fresh medium basis. Glutamine and glucose depletion or ammonia toxicity could cause depressed product titres when conditioned medium is used. Glutamine and glucose levels can easily be replenished in conditioned medium at minimal cost, and ammonia can be removed. Specific productivity was higher during cyclic batch operating mode than during batch operating mode. This may be because cyclic batch operating mode results in an incidental volume of conditioned medium at the beginning of each cycle. A two stage, cyclic-batch/batch operating mode can be employed to fully utilize medium and maximize product titre.
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  • 142
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    Aquatic ecology 34 (2000), S. 19-27 
    ISSN: 1573-5125
    Keywords: adaptation ; fitness ; food quality ; growth ; reproduction ; temporary ponds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Temporary pond Daphnia flourish on relatively poor-quality food, suggesting adaptation to stringent temporary pond conditions. We conducted laboratory life history experiments on populations of Daphnia obtusa from a shaded woodland temporary pond (short hydroperiod, dystrophic) and an open farmland temporary pond (long hydroperiod, eutrophic), and compared a suite of physical/chemical conditions in the ponds to evaluate habitat conditions. We hypothesized that the shaded woodland pond population would be more fit in terms of life history variables for individuals (age and size at first reproduction, mean brood size, mean number of neonates) and populations (generation time, net reproductive rate R 0, and intrinsic reproductive rate r) given a standard, low-quality food (trout chow and yeast). Life history traits of woodland pond animals were mixed, relative to farm pond animals, and consistent with bet-hedging for an unpredictable habitat. Values of life history traits rivaled or exceeded those of other studies using phytoplankton as food, and were influenced by the pond water used for our study. Life histories clearly differ among local and regional temporary pond Daphnia obtusa populations, and should be valuable for examining the relative influences of local selection and metapopulation dynamics on population structure.
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  • 143
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    Journal of applied phycology 11 (1999), S. 293-299 
    ISSN: 1573-5176
    Keywords: organismic determinants ; Gracilaria gracilis ; Rhodophyta ; regeneration ; growth ; mariculture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The growth of Gracilaria gracilis (Stackhouse) Steentoft, Irvine et Farnham was examined by studying the effect of organismic determinants such as thallus length, position along the thallus and branching. Knowledge of these factors is essential in order to increase production from suspended seaweed rafts seeded with vegetative G. gracilis fragments. Seeding netlons with seaweed material freshly collected from subtidal populations provided up to 30% higher relative growth rates than seaweed maintained on the netlons for successive months. Initial seedstock length greatly affected growth rates and yields such that 30-cm thalli fragments resulted in growth rates 14% higher than for 10-cm fragments. This difference is suggested to be due to the higher contribution to overall biomass by growth of lateral branches. Comparisons of the growth of apical and basal fragments suggest that growth takes place over the entire length of the thallus, but that the apex contributes more to overall elongation than does the proximal part. The removal of apical meristems resulted in an enhanced branching frequency with production of four times as many branches as intact fragments. Evidence is also provided for extensive morphological differentiation following long periods of rapid growth. These thalli have very high frequency of branching, are hollow due to the disintegration of medullary cells and are considered to be completely senescent. These factors have implications for the successful cultivation of G. gracilis on commercial mariculture systems.
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  • 144
    ISSN: 1573-5176
    Keywords: desiccation ; growth ; growth model ; inorganic carbon ; nutrients ; photoperiod ; photosynthesis ; pigments ; Porphyra linearis ; PPF ; respiration ; temperature ; water velocity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of environmental parameters on the growthof Porphyra linearis gametophytes was examinedunder controlled conditions, and related to themultilinear regression growth model recently developedfor this seaweed under coastal conditions in theeastern Mediterranean. Growth chambers, a gradienttable, special culture devices and analytical methodswere combined for this culture study.The major factors significantly controlling thegrowth rate of the P. linearis gametophytein glass dishes were: photoperiod, temperature, agein culture, photosynthetic photon flux (PPF), salinityand water dynamics. Maximal growth occurred underdaylength of 12 h, medium temperature (15–20 °C), low PPF (70–140 μmol photon m-2s-1), ambient salinity (30–40 ppt), 1–3 h ofdaily air exposure, and water velocity of 4 cm s-1.Photosynthesis and respiration rates weredominantly affected by daylength and temperature,while the concentration of pigments was dominantlyaffected by PPF and temperature.These conditions correspond well to the optimalnatural growth environment of this local species andare in agreement with the optimum estimated throughthe recently developed outdoor mathematical growthmodel.
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  • 145
    ISSN: 1573-5125
    Keywords: Marenzelleria ; Polychaetes ; macrozoobenthos ; abundance ; biomass ; population dynamics ; growth ; secondary production ; Baltic Sea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The propagation of an immigrant from North America, viz. the spionid Marenzelleria cf. viridis in the Darss-Zingst Bodden (DZB) (southern Baltic Sea), was studied at three stations from March 1992 to December 1995. Highest mean abundances (over 28 000 ind. m-2) and wet weights (400 g m-2) were recorded at station 2 in 1994. The spionid also reached its highest dominances in terms of biomass (40 to 90%) at this station, which was selected for the population dynamics, growth and secondary production studies. The spionid has a life span of about 3 years, and many individuals achieved sexual maturity after one year. Their growth curve is steepest during the first year of life, during which the animals grow to a length of about 180 segments. However, growth depression was observed during the ripening of the gametes in April, May and June. Secondary production was in the region of 55 to 85 g AFDW m-2 y-1. Productivity (P/B) varied considerably from generation to generation, ranging between 0 and 4.8 with an average between 1.2 and 1.6.
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  • 146
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    Journal of applied phycology 3 (1991), S. 319-327 
    ISSN: 1573-5176
    Keywords: Dunaliella viridis ; growth ; salinity ; temperature ; nitrogen concentration ; batch culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The growth of a strain ofD. viridis has been studied in batch culture under different combinations of temperature, salinity and nitrogen concentrations. Changes in these variables have a significant effect on cell division, biomass production, cell volume and pigment yield. This strain grows optimally at 1 M NaCl and 30 °C. Increasing salinity up to 4 M NaCl leads to a significant decrease of cell division rate and maximal population; growth at lower temperature decreases the rate of division of the cells but increases maximal cell density. Pigment yield decreases with increasing salinity and increases with increasing temperature. Nitrogen concentration has a large effect on total cell biomass and pigment production, but not on cell division rate. Saturation of growth occurs at 5 mM NO 3 − ; higher concentration (e.g. 10 mM) leads to a decrease of maximal cell density and photosynthetic pigment content.
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  • 147
    ISSN: 1573-5176
    Keywords: CO2 ; growth ; pH ; photosynthesis ; Porphyra yezoensis ; red alga
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Leafy thalli of the red algaPorphyra yezoensis Ueda, initiated from conchospores released from free-living conchocelis, were cultured using aeration with high CO2. It was found that the higher the CO2 concentration, the faster the growth of the thalli. Aeration with elevated CO2 lowered pH in dark, but raised pH remarkably in light with the thalli, because the photosynthetic conversion of HCO 3 − to OH− and CO2 proceeded much faster than the dissociation of hydrated CO2 releasing H+. Photosynthesis of the alga was found to be enhanced in the seawater of elevated dissolved inorganic carbon (DIC, CO2 + HCO 3 − + CO 3 − ). It is concluded that the increased pH in the light resulted in the increase of DIC in the culture media, thus enhancing photosynthesis and growth. The relevance of the results to removal of atmospheric CO2 by marine algae is discussed.
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  • 148
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    Journal of applied phycology 4 (1992), S. 311-313 
    ISSN: 1573-5176
    Keywords: Kappaphycus ; cage culture ; growth ; production
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Kappaphycus alvarezii var.tambalang was cultured in a 3 × 3 m bamboo raft installed inside a 4 × 4 m floating net cage ofLates calcarifer (sea bass) broodstock at SEAFDEC Sub-station Igang, Guimaras, Philippines, from December 1989 to May 1990. Growth and production ofK. alvarezii var.tambalang was influenced by the culture months. The highest growth rate and production were recorded in January and May, respectively, while the lowest growth rate and production were observed in March. Average growth rate (wet weight) ranged from 3.72 to 7.17% day-1, while production ranged from 575.5 to 2377 g m-1 line-1. A total production of approximately 123 t (fresh) or 37 t (dried) ha-1 in the 5-month harvest season was produced from this culture system. Cultivation ofK. alvarezii var.tambalang in cages is possible, which indicates that seaweeds can be grown with carnivorous finfish, a practice which is still untapped.
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  • 149
    ISSN: 1573-5176
    Keywords: nitrate uptake ; growth ; immobilized cells ; alginate bead ; Chlorella vulgaris
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Growth and nitrate uptake were studied on free-living and immobilizedChlorella vulgaris cells cultivated in medium containing different nitrate concentrations. First, the effect of nitrate concentrations on growth indicated that cells can live in the presence of high concentrations as high as 97 mM. Although no lethal effect on cells was observed such concentration a slow down in growth and a decrease in biomass produced was observed. The rate of nitrate uptake increased with the nitrate concentration in the medium. The maximum uptake rate was reached in first days of culture in both free-living and immobilized cells. The rate dropped more rapidly for cells growing in 2 mM nitrate than for cells growing in higher nitrate concentration. The maximum rate was very much the same for free-living and immobilized and was within the order of 0.45 to 0.57 μg NO3 h−1 10−6 cells. Immobilization modified the changes of nitrate uptake rate for concentration higher than 2 mM.
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  • 150
    ISSN: 1573-5176
    Keywords: Rhodophyceae ; Calliblepharis jubata ; growth ; carrageenan
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Study of the seasonal variation in the quality and content of iota carrageenan inCalliblepharis jubata from the Normandy coast of France shows that seasonal fluctuation of the environment affects the growth and chemical composition of this red alga. Growth increases during winter, when there is little synthesis of carrageenan and floridean starch is accumulated. When inorganic nitrogen content decreases, growth also decreases and stops (May to August); with high light intensity, the metabolism is oriented towards a synthesis of parietal carrageenans to the detriment of the reserve products such as floridean starch.
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  • 151
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    Journal of applied phycology 8 (1996), S. 87-103 
    ISSN: 1573-5176
    Keywords: Ascophyllum nodosum ; growth ; harvesting effects ; reproduction ; season ; survival
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Although populations ofAscophyllum nodosum are harvested commercially, little is known about the effects on demographic vital rates (growth, reproduction, survival). This study examines the effects of harvesting season and harvesting intensity on growth, reproduction and mortality of intact fronds in four size classes and in fronds truncated by the harvest. Knowledge of size-specific vital rates was used to evaluate the response of the population to harvesting. Harvesting season and harvesting intensity did not exert a significant effect on growth. Growth in plots not subject to harvesting was less than in harvested plots. No major differences in growth, reproduction and survival between intact and severed fronds emerged. The number of fronds attaining reproduction was enhanced by increased harvesting intensity and by cutting in summer. Harvesting did not seem to induce breakage, and breakage appeared higher in the uncut plots. Most harvesting treatments did not influence survivorship and survivorship was similar among all size classes. Growth rates were inversely related to sizes of fronds. Assessment of variation across size classes yielded more accurate estimates of growth rates than those of previously used methods. Accurate size class specific-growth rates will be a useful criterion when regulating intervals between harvests. Furthermore, assessment of size-specific vital rates allows identification of the frond size classes most relevant to the preservation of resources. Because of their fast growth rates and abundance, fronds in class 1, and, to a lesser extent, class 2, are responsible for most of the population regrowth after harvest. In contrast, classes 3 and 4 contribute little to recovery. This finding provides a strong basis for a harvesting strategy that targets the largest fronds.
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  • 152
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    Cytotechnology 20 (1996), S. 13-22 
    ISSN: 1573-0778
    Keywords: insect tissue culture ; cell-specific lines ; survival ; growth ; cell differentiation ; applications
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Conclusion Current methods of insect cell culture have produced a limited variety of cell types in an ever expanding list of insect cell lines. In developing midgut epithelial cell lines, we found that traditional methods in insect cell culture failed to provide healthy cells from mature tissues. Examination of mammalian cell culture literature for this particular cell type provided the insight required to successfully develop a cell-specific line (Baines et al., 1994). The potential applications for cell-specific lines from insects are numerous. This paper is a compilation of ideas that will hopefully enable other researchers to develop additional cell-specific lines.
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  • 153
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    Aquatic ecology 21 (1987), S. 141-147 
    ISSN: 1573-5125
    Keywords: Phaeocystis pouchetii ; P.globosa ; temperature tolerances ; colony shapes ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract An Arctic clone ofPhaeocystis pouchetii LAGERHEIM was compared toPhaeocystis globosa SCHERFFEL isolated from the southern North Sea with regard to temperature tolerance and colony shapes. Already youngP.pouchetii colonies (〈100 μm) show the typical distribution of the cells in groups, separated from each other by wide zones of cell-free mucilage; the maximum colony size is ca 2 mm in diameter.P.pouchetii colonies form clouds with bubble-like vesicles, spherical colony-shapes are seldom found.P.globosa colonies are spherical up to a size of 2 mm; the cells are distributed homogeneously over the periphery of the colonies. A ‘pouchetii’-like distribution of cells never occurs either in the spherical young colonies or in the pear-shaped old colonies (size up to 8 mm). A development from the colony shape of the ‘globosa’-type to the ‘pouchetii’-type or vice versa was never found. Therefore the colony shape has to be considered a constant distinctive character. Single cells ofP.pouchetii andP.globosa cannot be separated from each other by using the light microscope; this also holds for the flagellates and the non-motile cells.P.pouchetii grows well between 0°C and 14°C,P.globosa between 4°C and 22°C, respectively. Because of the distinctive differences in the morphology of the colonies and the differences in temperature tolerances we propose thatPhaeocystis globosa should no longer be considered conspecific withPhaeocystis pouchetii.
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  • 154
    ISSN: 1573-5125
    Keywords: crayfish ; Procambarus alleni ; growth ; Florida Everglades ; hydroperiod
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Environmental conditions influence crustacean growth by affecting molt intervals and incremental increases in length and weight. In the seasonally-flooded marl prairie wetlands of eastern Everglades National Park, U.S.A., hydropattern exerts considerable influence on aquatic primary productivity, and so may influence the availability of food resources for higher trophic levels. The seasonal hydroperiod has been drastically altered by anthropogenic factors, but the impacts on the aquatic community are not well known. We studied whether differences in growth of crayfish Procambarus alleni could be detected in habitats with different hydroperiods. We first described growth patterns based on incremental increases in length and weight of crayfish on a high protein diet in the laboratory. Regression analyses indicated that growth patterns in males and females were similar. Although the intermolt period increased with age, the proportional increases in length and weight were similar through successive molts. The relationship between length and weight of crayfish was best described by a power equation for allometric growth. We then compared growth curves for crayfish subpopulations from different areas of the marl prairie. In habitats with the longest hydroperiods, crayfish weight-at-size was not significantly different from that in laboratory crayfish on the high protein diet. However, weight gain per unit increase in length in short hydroperiod sites was significantly less than in long hydroperiod sites or in the laboratory. These results indicate that crayfish productivity may be associated with hydroperiod in these stressed wetlands, and this may contribute to observed source-sink population regulation.
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  • 155
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    Journal of applied phycology 11 (1999), S. 551-558 
    ISSN: 1573-5176
    Keywords: Nodularia ; growth ; hepatotoxin production ; nodularin ; salinity ; irradiance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The objective of this work was to determine the influence of total dissolved solids/salinity (TDS mgL-1) on growth and biomass specific rates of nodularin (hepatotoxin) production by Nodularia spumigena 001E isolated from Lake Alexandrina, South Australia. Maximum biomass yield (dry matter, chlorophyll a and particulate organic carbon/POC) at 80 μmol photon m-2 s-1 was recorded at 3300 mg TDS L-1 and decreased at salinities above or below this value (p 〈 0.05). The maximum biomass yield (dry matter and chlorophyll a) at 30 μmol m-2 s-1 occurred at a higher salinity of 9900 mg TDS L-1. Cultures grown at 80 μmol m-2 s-1, at a TDS〉 6600 mg L-1, had significantly (p 〈 0.05) lower nodularin content (ml-1 medium) than cultures grown at the same salinities at 30 μmolm-2 s-1. The maximum total toxin concentration (mL-1 medium) occurred at 9900 and 3300 mg TDS L-1 at 30 μmol m-2 s-1and 80 μmol m-2 s-1 respectively. Toxin per unit biomass, expressed as dry matter, chlorophyll a and POC was similar for cultures grown at 30 μmol m-2 s-1 or 80 μmol m-2s-1 at salinities 〈 6600 mg TDS L-1. At salinities 〉 9900 mg TDS L-1 the toxin content per unit biomass decreased at both irradiances, however, cultures grown at 30 μmol m-2s-1 had a higher toxin content than those grown at 80 μmol m-2 s-1. The results indicate that not only do changes in irradiance and salinity directly influence growth and toxin production but that changes in irradiance affected the influence of salinity.
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  • 156
    ISSN: 1573-5176
    Keywords: Gracilaria ; strain selection ; growth ; photosynthesis ; rubisco ; agar
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    Topics: Biology
    Notes: Abstract A strain selection procedure using Gracilaria verrucosa gametophytic sporelings was found to be an efficient tool for the improvement of Gracilaria strains. Two strains, C-2 and A-18, which were isolated and grown clonally, showed higher growth rates under high and low temperature conditions, respectively, than the local Gracilaria conferta. Growth rate, photosynthesis and chlorophyll, which were measured under different temperature and photon flux densities, demonstrated an overall advantage of the selected strains over the wild type strains of both G. verrucosa and G. conferta. Growth rates were also generally in positive correlation with the carboxylase activity of Rubisco. The G. verrucosa wild type also had a 40% higher agar content than G. conferta. The selected strains thus showed higher potential for outdoor cultivation than local wild type populations.
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  • 157
    ISSN: 1573-5125
    Keywords: Marenzelleria cf. viridis ; Polychaetes ; food limitation ; food selection ; growth ; gut passage time ; food quality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Phytoplankton 〈 20 µm was a principal dietary component of the larvae of Marenzelleria cf. viridis. Maximum ingested particle size increased as animal size increased, reaching a maximum diameter of 80 µm for larvae with 6 to 10 setigers. The larvae started ingesting particulate matter at the 1-setiger stage and were able selectively to ingest phytoplankton and polystyrene particles of various sizes. Larvae in the 6 to 10-setiger size group did not differ from those in the 11 to 17-setiger size group in respect of size selectivity for polystyrene particles. The gut passage time for Chlorella vulgaris was ≥ 20 min. The ingestion rate was limited by food concentrations even at concentrations much higher than those encountered in the natural biotope, saturation being reached at a concentration of 28.5 times 106 cells ml-1 (117.7 mg C l-1. The low maximum filtration rate of only 1.19 µl ind.-1 h-1 indicates that the filtering capacity of the larvae is low. The larvae are still capable of food uptake at 1 °C. Further experiments demonstrated that larval growth and survival were strongly dependent on both food concentration and quality. Larval growth was food-limited under biotope conditions of the Darss–Zingst Boddens and even more so under Baltic Sea conditions. The results indicate that Marenzelleria cf. viridis is a species adapted to eutrophic conditions prevailing in brackish waters.
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  • 158
    ISSN: 1573-5176
    Keywords: Botryococcus braunii ; exopolysaccharide biosynthesis ; temperature profiles ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Temperature profiles (range 20–33 °C) were obtained for growth and exopolysaccharide (EPS) biosynthesis of the microalga Botryococcus braunii strain UC 58 under photoautotrophic conditions. The maximum temperature for growth was 32 °C and the temperature dependence of the specific growth rate was described by the Hinshelwood equation based on the Arrhenius relationship. The optimal range of temperatures for growth and extracellular EPS synthesis (25–30 °C) concurred and production of 4.5–5 g l−1 of EPS was obtained routinely, leading to high broth viscosities. Below 23 °C EPS biosynthesis was negligible, although the specific growth rate maintained high values. At supraoptimal temperatures EPS biosynthesis decreased, accompanying the increase in doubling time. The polymers formed at temperatures within the optimal range for production, when dissolved in water, produced solutions (2 gl−1) with the highest viscosity, suggesting that their molecular weight showed the highest values. The degree of polymerization of the EPS synthesized at suboptimal and supraoptimal temperatures was significantly below the values within the optimal range.
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  • 159
    ISSN: 1573-5176
    Keywords: Dunaliella salina ; Chilean strains ; culture ; growth ; carotenogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A study was made of growth and carotenogenesis in eight strains of the green algaDunaliella salina collected from salt ponds at Salar de Atacama (23° 30′ S; 68° 15′ W) and Antofagasta (23° 39′ S; 70° 24′ W), Chile and kept in unialgal cultures at the Laboratorio Cultivo de Algas, University of Concepcion. The algae were grown in Erdschreiber medium supplemented with 12.5% w/v NaCl, under a continuous photon flux density of approximately 150 μmol m-2 s-1 at 25 ± 4 °C without aeration. When growth reached the stationary phase, the amount of NaCl was increased to 25%. Total carotenoid content was measured during the exponential growth phase and 20 days after the addition of salt. Strain CONC-001 (Laguna La Rinconada, Antofagasta) exhibited the highest growth rate (k = 0.32 div d-1) and the lowest total carotenoid content (7.2 and 13.7 mg l-1 at 12.5 and 25% NaCl, respectively). Strain CONC-007 (Salar de Atacama) had the lowest growth rate (k = 0.14 div d-1) and yielded the highest total carotenes per volume unit (23.1 and 35.6 mg 1-1 at 12.5 and 25% NaCl) and per cell (ca. 42 pg at 25% NaCl). Total carotenoid synthesis did not increase in strains CONC-001 and CONC-006 with the increase of salinity. These strains had the greatest increase of total carotenoid-to-chlorophyll ratio (4.5- and 9.3-fold, respectively). The seven strains from Salar de Atacama had higher total carotenoid contents than the strain from Antofagasta. Cell size also varied. Strain CONC-001 cells were smallest; strain CONC-006 had the largest cells. There was an inverse correlation between maximum cell density and mean cell size.
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  • 160
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    Aquatic ecology 32 (1998), S. 261-279 
    ISSN: 1573-5125
    Keywords: phosphorus ; fatty acid ; growth ; life history ; food limitation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Evidence suggests that marine and freshwater zooplankton generally experience food levels above subsistence values in terms of carbon. However, the quality of this food may be poor due to an insufficiency of other essential nutrients. In this review, we examine recent progress in three main areas of food quality research: (1) elemental (especially P) limitation, (2) digestion resistance, and (3) biochemical (especially fatty acids) limitation. We evaluate laboratory and field evidence in each of these areas, look at new evidence about the life history implications of the elemental limitation hypothesis, and suggest future avenues for research. From a rather large number of seemingly heterogeneous studies, a single consistent picture of food quality emerges: both P and essential fatty acids are predicted to be important dietary factors, but at different places and times. Nevertheless, despite an abundance of valuable laboratory studies, our knowledge of food quality limitation in the field is still poor.
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  • 161
    ISSN: 1573-5176
    Keywords: microalgae ; temperature ; growth ; total lipids ; fatty acids ; tropical mariculture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of temperature from 10 °C to 35 °C on the growth, total lipid content, and fatty acid composition of three species of tropical marine microalgae, Isochrysis sp., Nitzschia closterium, N. paleacea (formerly frustulum), and the Tahitian Isochrysis sp. (T.ISO), was investigated. Cultures of N. closterium, Isochrysis sp. and T.ISO grew very slowly at 35 °C, while N. closterium did not grow at temperatures higher than 30 °C or lower than 20 °C. N. paleacea was low-temperature tolerant, with cells growing slowly at 10 °C. N. paleacea produced the highest percentage of lipids at 10 °C, while the other species produced maximum amounts of lipid at 20 °C. None of the species maintained high levels of polyunsaturated fatty acids (PUFAs) at high growth temperature and there was a significant inverse relationship between the percentage of PUFAs and temperature for N. paleacea. A curved relationship was found between temperature and percentage of PUFA for N. closterium and tropical Isochrysis sp., with the maximum production of PUFA at 25 °C and 20 °C, respectively. The two Nitzschia species produced higher levels of the essential fatty acid eicosapentaenoic acid [20:5(n-3)] at lower growth temperatures, but the two Isochrysis species had little change in percentage of 20:5(n-3) with temperature. Only T.ISO had the highest percentage of 22:6(n-3) at lowest growth temperature (11.4% total fatty acids at 10 °C).
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  • 162
    ISSN: 1573-5176
    Keywords: Lyngbya wollei ; paralytic shellfish poisons ; growth ; toxin production
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Collections of Lyngbya wollei were taken from Guntersville Reservoir, Alabama, over a period of three years. Healthy filaments were isolated and transferred to agar plates of Z-8 and LM6E media. Unialgal isolates were cultured for the study of growth and paralytic shellfish poison (PSP) production. Filaments were extracted and the toxins were detected using high performance liquid chromatography (HPLC) with post column oxidation followed by fluorescence detection. HPLC profiles show that laboratory cultures of L. wollei produced decarbamoyl gonyautoxin 2 and 3, plus several other PSP like toxins whose structures are under investigation. At 26 °C and a light intensity of 11 or 22 µmol m-2 s-1 optimum production of both biomass and toxins occurred. A decrease or increase in temperature or light flux caused a reduction in dry weight or toxicity. Compared to control levels, lower PO4-P and NO3-N and higher calcium levels gave rise to higher biomass and toxicity. Lower calcium, calcium- or PO4-P deficient medium and high NO3-N or PO4-P caused a large decrease in dry weight and toxicity.
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  • 163
    ISSN: 1573-5176
    Keywords: seaweed ; Agardhiella ; carrageenan ; phosphorus ; cultivation ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Gas liquid chromatography, chemical analyses, and infrared and13C-NMR spectroscopies indicated that phycocolloids extracted fromAgardhiella subulata had a dominant ι-carrageenan feature with less deviant ι-carrageenan and υ-carrageenan. The presence of methylated galactose and a small contamination by xylose were registered. Unattached plants were cultivated for 4 weeks in tanks receiving seawater enriched with 53.5 µM nitrate and 0 to 20 µM phosphate (Pi) week−1. The growth was phosphorus (P)-limited up to a tissue P content of 0.14 ± 0.03% dry weight. Maximal specific growth rate and carrageenan content were observed with enrichments of 6 µM Pi and 3 µM Pi, respectively. Hence carrageenan production was promoted in the range of 3–6 µM Pi. Further Pi enrichment was useless. This phenomenon, observed with P nutrition, is comparable to the ‘Neish effect’ in nitrogen nutrition studies.
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  • 164
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    Bulletin of experimental biology and medicine 103 (1987), S. 699-703 
    ISSN: 1573-8221
    Keywords: capillary ; colchicine ; proliferation ; cornea ; growth
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    Topics: Biology , Medicine
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  • 165
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    Bulletin of experimental biology and medicine 98 (1984), S. 1159-1161 
    ISSN: 1573-8221
    Keywords: motor response ; growth ; catecholamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
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  • 166
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    Journal of pharmacokinetics and pharmacodynamics 10 (1982), S. 335-348 
    ISSN: 1573-8744
    Keywords: pharmacokinetics ; bioavailability ; growth ; literature growth ; logistic function
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The literature growth in pharmacokinetics and bioavailability between the years 1964 and 1980 is analyzed. During much of this period, the literature doubled approximately every 1.6 years. However, during the period 1978–1980, little or no growth was observed. During the period 1950–1967, the total chemical literature increased exponentially with a half-life of 8.28 years; between 1968 and 1980, the half-life was 12.4 years. Thus, the pharmacokinetic literature increased at a much more rapid pace than did the total chemical literature in general. The subject of growth is considered in a general context, particularly as influenced by psychological, sociological, political, and economic factors. It is concluded that while mathematical functions may adequately describe past literature trends, they have little if any utility in predicting future trends in specific research areas such as pharmacokinetics.
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  • 167
    ISSN: 1573-8477
    Keywords: amphibian ; body size ; clonal ; genetic compatibility ; growth ; hybridogenesis ; local adaptation ; metamorphosis ; Rana esculenta ; tadpole
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Hybridogenetic species possess a hybrid genome: half is clonally inherited (hemiclonal reproduction) while the other half is obtained each generation by sexual reproduction with a parental species. We addressed the question of whether different hemiclones of the hybridogenetic water frogRana esculenta are locally adapted for genetic compatibility with their sexual parental hostRana lessonae. We artificially crossedR. esculenta females of three hemiclones (GUT1, GUT2 and GUT3) from a pond near Gütighausen, Switzerland and one hemiclone (HEL1) from near Hellberg, Switzerland each toR. lessonae males from both populations. We also created primary hybrids by crossing the sameR. lessonae males from both populations toR. ridibunda females from Poznań, Poland (POZ). Tadpoles were then reared in the laboratory at two food levels to assess their performance related to early larval growth rate, body size at metamorphosis and length of the larval period. Tadpoles from hemiclones GUT1, GUT3 and POZ had higher growth rates than those from hemiclones GUT2 and HEL1 at the low food level, but at the high food level all growth rates were higher and diverged significantly between hemiclones GUT2 and HEL1. Tadpoles from the intrapopulational crosses GUT2 × GUT and HEL1 × HEL were larger at metamorphosis than those from the interpopulational crosses GUT2 × HEL and HEL1 × GUT. A high food level increased the size at metamorphosis in all tadpoles. A high food level also decreased the days to metamorphosis and tadpoles from GUT1, GUT3 and POZ had the shortest larval period whereas those from GUT2 and HEL1 had the longest. These results indicate that the differential compatibility of clonal genomes may play an important role in hybridogenetic species successfully using locally adapted sexual genomes of parental species and that interclonal selection is likely important in determining the distribution of hemiclones among local populations.
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    Water resources management 13 (1999), S. 73-84 
    ISSN: 1573-1650
    Keywords: chlorophyll ; growth ; rice crop ; spectral reflectance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geography
    Notes: Abstract Relations among spectral reflectance, chlorophyll ‘a’, and growth of rice plants grown on irrigated light textured soil in a semi arid region are presented here. There was a linear relation between spectral reflectance and rice plant height (r = 0.97), for band 1 (0.45–0.52 μm) reflectance values. On the other hand, in bands 2 (0.52–0.60 μm) and 3 (0.63–0.69 μm), reflectance values decreased until 70 days after planting (DAP) and then increased during the reproductive phase of the crop. The near infrared band 4 (0.76–0.90 μm) showed a maximum reflectance at 59 DAP (panicle initiation stage) and a decline in reflectance thereafter through maturity. The peak value of IR/R ratio was 16.39 at 62 DAP during the early reproductive phase; thereafter, it declines gradually with the maturity of the crop. Chlorophyll ‘a’ concentration was high during early growth (vegetative and early reproductive stages) and decreased during the flowering and maturity stages. The rice plant canopy show a high chlorophyll ‘a’ concentration at 64 and 59 DAP for sites A and B, respectively. Chlorophyll ‘a’ concentration is higher in site A plant canopies than it is in site B during the entire crop cycle. A good inverse correlation (r = 0.91) has been found between chlorophyll ‘a’ and band 1, while the IR/R ratio and the normalised difference vegetation index (NDVI) showed a relationship (r = 0.78) with the chlorophyll ‘a’ concentration during the crop cycle. Band 2, 3 and 4 radiance values show a biphasic linear relationship with chlorophyll ‘a’ concentrations, negative for early growth and positive for flowering and maturity stages. Results indicate that the period between 66 to 70 DAP is most suitable for the assessment of rice crop yield, based on chlorophyll ‘a’ concentration.
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  • 169
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    Aquaculture international 7 (1999), S. 251-260 
    ISSN: 1573-143X
    Keywords: bacterial biofilm ; common carp (Cyprinus carpio) ; growth ; rohu (Labeo rohita) ; Tilapia (Oreochromis mossambicus)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Experiments were conducted to enhance the growth of common carp (Cyprinus carpio), rohu (Labeo rohita) and Mozambique tilapia (Oreochromis mossambicus) through use of sugarcane bagasse as substrate. Bagasse was suspended in water with or without supplementation with fertilizers. Bagasse supplemented with cattle dung and urea favoured higher zooplankton production and significantly (p 〈 0.05) increased fish growth by over 50% compared to bagasse or fertilizers on their own. This higher production of fish is attributed to bacterial biofilm promoted on the substrate which, apart from forming food for zooplankton and fish, contributed to improved water quality by lowering ammonia.
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  • 170
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    Aquaculture international 8 (2000), S. 159-168 
    ISSN: 1573-143X
    Keywords: emersion ; growth ; Pecten maximus ; scallop spat ; survival ; transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Scallop spat production normally requires transfer between growthsystems. Simulated transport experiments were carried out in April, June,December and February to evaluate effects of transport time on greatscallop (Pecten maximus) spat growth and survival. The spat (1.7–1.8 mm in shell-height and 21–25 µg ash free dry weight [AFDW]) wereheld in moist coffee filters at a temperature of 10 °C for up to 24 h,before being replaced into sieves in rearing tanks at 15 °C. The studyshowed that by increasing air emersion time, survival and growthdecreased. No significant difference in the results between 0 and 4 h of airemersion was found, while the effects after 12 and 24 h differed betweenspat groups. Survival and growth rates showed seasonal differences. Meansurvival was 35–71% in April and 77–99% from June to February. In Junemean growth rates attained were 115–128 µm shell-height and 15–18µg AFDW per day compared with 49–69 µm and 3.8–7.0 µgper day for the other spat groups. Great scallop spat may survive atransfer time of 24 h, but transportation for longer than 12 h is notrecommended if subsequent high survival and growth rates are to beensured.
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  • 171
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    Aquaculture international 8 (2000), S. 207-225 
    ISSN: 1573-143X
    Keywords: growth ; mortality ; Pecten maximus ; suspended culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Growth and mortality of the king scallop, Pecten maximus, werecompared when grown in cages and by ear hanging in suspended culturein Fuengirola, Malaga, in southern Spain. Seed (juveniles) used in theexperiment was collected in September 1997 that had settled on collectorsin April-June, of that year. Culture in suspended cages began in January1998 when the seed measured 42.7 (3.3) mm shell height and ended inFebruary 1999. Significantly faster growth was found at a minimum culturedensity (16 scallops/cage) than at two other densities (24 and 36scallops/cage). Depth (1, 5 and 10 m from the bottom) influenced growth,poorest growth occurred closest to the bottom. Under optimum growingconditions, 16 scallops/cage suspended 10 m from the bottom, scallops grewto 10 cm shell length (legal size) by February 1999.In ear hanging culture, ropes were moored in April (51.3 (4.5) mm),June (58.2 (4.5) mm) and November 1998 (64.3 (4.9) mm).Initially, rapid shell growth was observed in all three cultures.Subsequently, the shells became covered with barnacles, Balanus sp.,that possibly caused total mortality of the April culture and led to highmortalities in the two other cultures.
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  • 172
    ISSN: 1573-143X
    Keywords: growth ; silver perch (Bidyanus bidyanus) ; size grading ; size variation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract This study presents two experiments addressing growth and size variation in fingerling silver perch (Bidyanus bidyanus. In the first experiment, fish close to mean population size were raised either in the presence or absence of five larger fish for 60 days. Mean specific growth rate (SGR) and increases in the coefficient of variation and skewness were lower in the presence of larger fish, indicating a negative effect of large fish on the growth of smaller ones. In the second experiment, fingerlings were graded into groups smaller and larger than the median size of the population and raised in size-sorted groups of 60 large or small fish and mixed groups of 30 fish of each size category, for 60 days. There was no difference in mean SGR among groups, nor between the mixed group ad the weighted mean of the small and large groups. Biomass gain was higher in the mixed groups than in the weighted small-and-large groups, probably due to a slightly lower survival in the groups comprised of large fish. The fact that the effect of large fingerlings on the growth of smaller ones was evident in the first, but not the second, experiment may be attributed to higher size disparity between large and small fingerlings in the first experiment.
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  • 173
    ISSN: 1573-143X
    Keywords: 17 β-estradiol ; fish meal ; gonadal development ; growth ; Nile tilapia (Oreochromis niloticus) ; plant proteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract This study was conducted to evaluate theeffect of plant protein‐based diets on gonadaldevelopment and plasma 17 β-estradiol (E2) levelin female Nile tilapia Oreochromis niloticus.Fish with a mean body weight of 6.7 (0.1) g were fedfour different diets with the same digestible protein(DP) and digestible energy (DE) containing gradedlevels of a mixture of plant ingredients as partial ortotal replacement of fish meal protein for 20 weeks.The control diet (D0) was based on fish meal, twodiets containing 33% (D33) and 66% (D66) of plantprotein, and one diet containing only plant protein(D100). Fish were sampled at 12 and 20 weeks. Nosignificant differences were found in different stagesof oocyte development and plasma E2 levels betweentilapia fed diets D0 and D100 at 12 weeks. Eight weekslater tilapia fed diet D0 showed a higher (P 〈 0.05)level of E2 than the D100 group. This difference andthe reduced proportion of vitellogenic and matureoocytes demonstrated that diets containing only plantprotein are less efficient in terms of tilapia growthand consequently ovarian development.
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  • 174
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    Aquaculture international 8 (2000), S. 455-461 
    ISSN: 1573-143X
    Keywords: floating cages ; growth ; pink dentex (Dentex gibbosus) ; sparids (Dentex dentex, Sparus aurata, Spondyliosoma cantharus, Diplodus puntazzo)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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  • 175
    ISSN: 1573-143X
    Keywords: Convict cichlid (Cichlasoma nigrofasciatum ; environmental UV effects ; growth ; ultraviolet radiation ; UVA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The long term (two generations) effect an enhanced (5%) sub-lethal ultraviolet-A (320–400 nm) irradiation on growth and survival rate of a convict cichlid (Cichlasoma nigrofasciatum is presented. Two UVA irradiated populations (G1-UVA and G2-UVA) and two control populations (G1-control and G2-control) were observed from age 60 to 403 days. The UVA populations were exposed to enhanced UVA irradiation from 4 months of age (G1-UVA and from egg's state (G2-UVA). The specific growth rates (daily weight and length increase) and the condition factors of the populations were not affected by the enhanced UVA, it depended more on the population size. At the adapted temperature range (27–29 °C) the survival rate of those populations was not affected by enhanced UVA. A combined effect of enhanced UVA and increased temperature (31–32 °C) was responsible for a high mortality rate in the GI-UVA. A total of 67% of the G1-UVA population died just within a week of exposure to high temperature.
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  • 176
    ISSN: 1573-143X
    Keywords: body composition ; dietary protein ; fecundity ; gonad maturation ; growth ; Nile tilapia (Oreochromis niloticus)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Six-week-old Nile tilapia (Oreochromis niloticus) fry with an average weight (SD) of 0.51(0.2) g were reared for 140 days on five formulated, isocaloric diets of different protein levels (25, 30, 40 and 45% by dry weight). Fish fed diets of higher protein levels (40 and 45%) showed better growth and feed conversion ratio than those on lower protein levels. Fast-growing fish matured earlier. Maturation rate was affected by the dietary protein levels. Males matured earlier than females: the first mature males were recorded when they were 14 weeks old, whereas the females matured after 18 weeks. In both sexes, mean percentage of mature fish rose with increasing dietary protein level, the percentage of mature males being higher than that of the females. Similarly, the percentage of mature fish rose with the increasing age of fish, with more than 50% males and females mature at the age of 22 and 24 weeks, respectively, the exception being the 25% protein diet fed fish, where the percentage of mature fish was below 50%. In all treatments, spawning was initiated when the fish were 22 weeks old. Smallest size at spawning of males and females was 9.2 cm (13.1 g) and 8.1 cm (8.9 g), respectively, and dietary protein levels influenced the size of fish at first maturity. For both sexes, no difference was found in the gonado-somatic index (GSI) among different treatments. Fecundity increased with increasing dietary protein levels, but significant differences were found only between 40–45% and 25–35% dietary protein levels. The relative fecundity (eggs g−1 female) was higher at the lower dietary protein levels (25–35%) than at the higher dietary protein levels (40–45%). The dietary protein levels did not have any significant influence on the size and weight of mature eggs. The chemical composition of fish and mature ovaries was significantly influenced by the dietary protein level.
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  • 177
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    Aquaculture international 7 (1999), S. 179-187 
    ISSN: 1573-143X
    Keywords: feeding ; growth ; larvae ; micro-algae ; pearl oyster (Pinctada margaritifera L.) ; survival
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract This paper reports on an experiment to determine growth and survival of blacklip pearl oyster, Pinctada margaritifera (L.), larvae fed a 1:1 mixture of Isochrysis aff. galbana clone T-ISO and Pavlova salina at six different densities (1, 2, 5, 10, 20 and 30 × 103 cells ml-1. Larval growth and survival were assessed every four days over a 20–day period. Exponential and logistic regression models were fitted to the growth and survival responses, respectively. Overall growth of larvae fed ≥5 × 103 cells ml-1 was significantly greater (p 〉 0.01) than growth of larvae reared at other algal densities. The optimal food ration for maximum larval growth was 20 × 103 cells ml-1, which resulted in larvae with antero-posterior shell length of 230 μm after 20 days. These larvae were significantly larger (p 〉 0.05) than those in all other treatments at the end of the experiment. Survival of larvae fed 0, 1 and 2 × 103 cells ml-1 was significantly lower than that of larvae in all other treatments at the end of 15 days (p 〉 0.01). Maximal survival (8%) over the 20 day period was shown by larvae fed 10 × 103 cells ml-1, while lower survival was shown by larvae fed 2 × 103 cells ml-1 (2%) and 1 × 103 cells ml-1 (0%).
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  • 178
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    Aquaculture international 7 (1999), S. 201-205 
    ISSN: 1573-143X
    Keywords: fingerlings ; growth ; light regimes ; photoperiod ; silver catfish (Rhamdia quelen) ; survival
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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  • 179
    ISSN: 1573-143X
    Keywords: gilthead sea bream (Sparus aurata) ; growth ; hybridization ; red porgy (Pagrus pagrus) ; survival
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Hybridization between gilthead sea bream, Sparus aurata, and red porgy, Pagrus pagrus, was undertaken and viable hybrids were produced by an artificial hormonal-induced cross. The hybrids, from the cross of female red porgy and male gilthead sea bream (Pp × Sa), survived through the yolk-sac larval stage. The hybrids produced from the cross of female gilthead sea bream and male red porgy (Sa × Pp) presented higher mortality in the larval stage (98.4%) compared to gilthead sea bream (80.0%) and red porgy (92.5%). Afterwards, the Sa × Pp hybrid was compared to the offspring of its parental species under the same rearing conditions (tanks of 500 l capacity, natural light, ambient temperature, self-feeding with commercial feed) in a 40–week experiment. In this comparative study, the Sa × Pp hybrid had intermediate mortality rate (6%), compared to gilthead sea bream (0%) and red porgy (21%). The growth profile of this hybrid resembled the slow growing phases of its parents (red porgy in warm period and gilthead sea bream in cold period). The feed conversion ratio between fish forms was not significantly different (1.54–1.84 in the Sa × Pp hybrid, 1.53–1.56 in the maternal species and 1.33–1.40 in the paternal one). The body weight variation in the Sa × Pp hybrid was quite high (31.7–37.9%), compared to that in gilthead sea bream (19.7–24.7%) and red porgy (18.0–31.3%). With respect to body coloration, the Sa × Pp hybrid was distinguishable and classified into groups of red porgy-like (55.1%), gilthead sea bream-like (40.6%), and intermediate forms (4.3%). The preliminary results of this study proved that the produced Sa × Pp hybrid had too low a performance for aquaculture use, but the interesting consequent hereditary potential could be a useful tool in fish hybridization practice.
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  • 180
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    Aquaculture international 7 (2000), S. 369-382 
    ISSN: 1573-143X
    Keywords: growth ; haddock (Melanogrammus aeglefinus) ; larvae ; light intensity ; photperiod ; tank colour
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In two separate experiments, haddock (Melanogrammus aeglefinus) larvae were raised under different photoperiods (24L : 0D or 15L : 9D), or different combinations of tank colour (black or white) and light intensity (1.1 μmol s−1 m−2 or 18 μmol s−1 m−2). Growth (0.8% day−1 in standard length; 2.9% day−1 in body area) and survival (2%) were not significantly different between photoperiod treatments after 35 days. Larval survival was greater in white versus black tanks after 41 days (2% versus l%, respectively). Growth of larvae was impaired in black tanks at low (1.1 μmol s−1 m−2) light intensity (0.8% day−1 in standard length and 2.2% day−1 in body area versus 1.1% day 21 in standard length and 3.1% day−1 in body area, for all other treatments). Transmission and reflection of light was low in black tanks at low incident light, and there was very little upwelling light. The resultant poor prey to background contrast probably resulted in larvae being unable to consume sufficient food to sustain a level of growth comparable to that in other treatments.
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  • 181
    ISSN: 1573-143X
    Keywords: bivalve ; fouling ; growth ; Newfoundland ; nursery ; sea scallop (Placopecten magellanicus) ; spat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Hatchery-reared sea scallop (Placopecten magellanicus) spat weremonitored for growth and recovery in three experiments to determine themost suitable system for nursery culture. In Experiment I, four size classesof nursery-sized spat held at two depths from October to July exhibiteddeclining growth rates over the winter period and increased growth ratesin the spring. Overall, season, depth and initial size had a significantinfluence on the absolute and specific growth rates of scallops. Recovery,defined as number of scallops remaining after mortality and loss of spatthrough gear mesh, was influenced by season and initial size, but notdepth. Scallops in the 3.0 mm+ size class had higher growth rates andrecovery than those in the 1.4–1.6 mm, 1.7–1.9 mm and 2.0–2.9 mm sizeclasses. In Experiment II, two gear types containing similar size spat werecompared. Growth rates were significantly higher in 3.0 mm pearl nets thanin 3.0 mm collector bags, although recovery was similar between the twoequipment types. Experiment III, two stocking densities of nursery-sizedspat were compared in collector bags. Neither growth rate nor recoverywere significantly different for the two densities (2600 and 5200spat/collector bag) tested. Overall, these studies indicated that importantparameters for optimizing the growth and recovery of scallops in a farm-based nursery system include season, initial spat size, deployment depthand gear type.
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  • 182
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    Aquaculture international 8 (2000), S. 381-389 
    ISSN: 1573-143X
    Keywords: Arctic charr (Salvelinus alpinus) ; growth ; low temperature ; stocking density ; time restricted feeding,/kwd〉
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effects of time restricted feeding, possibility of bottomfeeding and stocking density on the growth of Arctic charr(Salvelinus alpinus L.) were examined in fish held at lowtemperature (〈2 °C). Fish fed for a restricted time (1 h) hadsignificantly (p 〈 0.05) lower specific growth rate (0.15 vs0.32% per day) than those fed the same ration over an extendedtime period (12 h). Increasing stocking densities had a positive andsignificant effect (p 〈 0.05) on growth with SGR increasing from 0.27to 0.52% per day at 2–30 kg m-3. Fish withaccess to feed on the tank floor had a significantly higher (p 〈0.05) growth rate (0.3 vs 0.13% per day) than those without thepossibility to feed from the bottom. When fish were held underconditions without access to the bottom a doubling of the feed rationdid not result in a significant (p 〉 0.05) increase in growth rate(0.13 vs 0.12%percnt; per day).
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  • 183
    ISSN: 1573-1448
    Keywords: anaesthetic ; growth ; Haemulidae ; 2-phenoxyethanol ; Pomadasys commersonnii
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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  • 184
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    Aquarium sciences and conservation 2 (1998), S. 9-19 
    ISSN: 1573-1448
    Keywords: Barbus tetrazona ; nutrition ; dietary requirement--phosphorus ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effects of increasing dietary concentrations of phosphorus on growth, feeding efficiency and body composition were studied in the tiger barb (Barbus tetrazona) (Bleeker, 1855). Juvenile tiger barbs (initial weight 0.33 ± 0.02 g) were fed purified diets containing graded levels of KH2PO4 to provide 0.17--1.57% available dietary phosphorus for 8 weeks in freshwater glass aquaria. The weight gain, feeding efficiency and mineral composition of the whole body and bone were significantly (p 〈 0.05) affected by dietary phosphorus. Growth response data calculated by broken line analysis showed that the minimum dietary phosphorus level required for maximum growth was 0.52%. The carcass protein, fat and ash contents but not moisture were affected by various dietary phosphorus levels. Fish fed a low-phosphorus diet had high body crude fat
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  • 185
    ISSN: 1573-5117
    Keywords: grapsid crabs ; detritivory ; growth ; survival ; assimilation efficiency
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The growth performance of adult individuals of the detritivorous mangrove grapsid crabs Chiromanthes bidens and Parasesarma plicata common in the Mai Po marshes, Hong Kong, was followed in a long-term laboratory rearing experiment (10 months). Individual crabs' moulting frequency, growth increment and mortality when fed four kinds of leaf litter available in their natural habitats, viz. brown (two weeks of decomposition) and yellow (fresh litter) Kandelia candel, and brown and yellow Avicennia marina were followed. The survival period was strongly related to litter type when the data from both crab species were pooled, being longest for crabs fed with brown Avicennia marina, followed by brown Kandelia candel 〉 yellow Avicennia marina 〉 yellow Kandelia candel. A higher proportion of crabs moulted twice when yellow Avicennia marina was supplied, but more crabs moulted for a third time when fed with brown Avicennia marina. The growth increment of the two species of crabs after moulting was found to be significantly related to their pre-moult size (ANOVA, P〈0.05), but effects of the four treatments were non-significant. Increment of Chiromanthes bidens was significantly greater than that of Parasesarma plicata under the brown Kandelia candel treatment. Litter treatment has no effect on the time taken for the crabs to moult, only in the case of the yellow Avicennia marina treatment did Parasesarma plicata take a longer time to moult a second time.
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  • 186
    ISSN: 1573-5117
    Keywords: Mangrove ; Kandelia candel ; seedling ; growth ; wastewater ; pollution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A greenhouse experiment wad performed to evaluate the effects of synthethic wastewater in three different strengths, NW, MW and CW, on the growth of the one-year old Kandelia candel (L.) Druce plants. NW had the characteristics and strength similar to natural municipal wastewater while MW and CW contained five and ten times of the nutrients and heavy metals in NW, respectively. Artificial seawater was used as the control. During one year wastewater treatment experiment, Kandelia were found to withstand wastewater of high strength and toxic symptoms were not detected in all plants. Synthethic wastewater with strength similar to the natural municipal sewage (NW) stimulated plant growth. The plants treated with NW had significantly higher aerial and root biomass, taller stem than those found in the CW, MW and the control. Maximum growth, in terms of both stem height and total biomass, of all plants occured in summer months, from June to September. With respect to the physiological and biochemical activities, CW and MW treated plants had significantly lower levels of chlorophyll a, total chlorophyl and catalase activity than those found in NW and control groups. In contrast, the proline content of plants treated with wastewater was similar to that of the control. These result suggest that normal wastewater (NW), attributed to its nutrients and trace elements, enhanced plant growth. The medium (MW) and concentrated wastewater (CW) supported similar amount of plant growth as the control but the physiological and biochemical parametes indicate that these treated plants might have been exposed to some kind of stress, probably due to the heavy metals present in MW and CW.
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  • 187
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    Hydrobiologia 319 (1996), S. 15-21 
    ISSN: 1573-5117
    Keywords: brachyuran crab ; fecundity ; growth ; Metopograpsus messor ; reproduction ; seasonal changes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The annual cycle of a Metopograpsus population (Muzhupilangad estuary) had three distinct periods: (1) growth-reproduction (January–May), when crabs were involved in moult and reproduction; (2) inactive period (June–July), and (3) reproductive period (August–December). Usually, spawning was immediately followed by another vitellogenic cycle, paralleled by the embryogenesis of prehatch eggs in the brood. Moulting was seemingly an annual event. In the programming of moult and reproduction, the species deviated from the common brachyuran pattern, inasmuch as the postmoult females engaged in active vitellogenesis. The synchrony in the stages of maturation and spawning, and the precision with which the physiological events are programmed, make this highly fecund species an ideal model for an integrated study of the physiology of growth and reproduction.
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    Hydrobiologia 325 (1996), S. 39-46 
    ISSN: 1573-5117
    Keywords: roach ; pike ; chub ; growth ; river zones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Variation in the growth patterns of roach, Rutilus rutilus (L.), pike, Esox lucius L., and chub, Leuciscus cephalus (L.) was examined along the upper Warta River, where human impact (mostly pollution) has influenced the longitudinal zonation on the fish assemblage. Significant differences were found in the exponent of weight-length relationships for roach and chub populations occupying different zones of the river, but no such variation was observed in pike. Moreover, pike growth was isometric, whereas roach and chub grew allometrically, with regression coefficients (slope) above 3. Although the length-at-age data were similar for each zone, the von Bertalanffy parameters (L inf, K and t 0) suggest that there may exist some inter-zone variation in the overall growth patterns of these species. All the species grew better in the zone where the index of relative abundance (relating dominance of a particular species to its maximum abundance in river system) achieved its highest value. The results suggest that a relative abundance index expressed in this way can be a good index of ‘habitat quality’.
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  • 189
    ISSN: 1573-5117
    Keywords: β-carotene ; baker's yeast ; growth ; survival
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Coloration of phyllopods varies from place to place and from one life stage to another. It ranges from translucent or whitish through gray, blue, green, orange, and reddish. Here, we present experimental evidence for a food- dependent color pattern inThamnocephalus platyurus Packard. The presence or absence of the synthetic pigment trans — β — carotene in a baker's yeast diet was the controlling factor. All the 24 old larvae used in the experiment were whitish in color. From day 6 until the end the experiment (day 11), 100% of the shrimps under a diet with synthetic trans — β — carotene (treatment 1) exhibited a characteristic color pattern which consisted of an orange color in the cercopods, and in all theracopods; the rest of the body exhibited no particular color. In comparison, 100% of the shrimps under a diet without synthetic trans — β — carotene (treatment 2) were whitish throughout the body. In females from treatment 1, the ovaries and oocytes were green-bluish, while in females from treatment 2 the ovaries and oocytes were whitish. No significant differences in survival and growth were found, except that at day 9, there was a significant difference in growth, the females with the synthetic trans — β — carotene group growing faster.
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  • 190
    ISSN: 1573-5117
    Keywords: Thamnocephalus ; Branchinecta ; growth ; filter-feeders ; feeding ; clay ; silicium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We designed and standardized a culture method for freshwater anostracans using diets free of live algae.Thamnocephalus platyurus andBranchinecta lindahli were used as test organisms. We used baker's yeast as basic food and added inert particles (clay or amorphic silicium dioxide) to improve the digestion of the yeast. A flow-through culture system was used, according to a fixed feeding schedule, to supply separately, culture medium (tap water), food, and inert particle suspensions. Three variants with baker's yeast as basic, food were compared for survival, growth, and reproduction. A diet of solely baker's yeast (diet 1) or baker's yeast supplemented with vegetal oil containing ß-carotene (diet 2) was unsuitable for reproduction ofT. platyurus. Cyst production was only achieved when diet 2 was supplemented with fish oil andSpirulina powder (diet 3). This suggests that not only a digestibility problem, but also nutritional deficiencies are present in baker's yeast.
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  • 191
    ISSN: 1573-5117
    Keywords: Anostraca ; algal food ; temperature ; conductivity ; water quality ; growth ; maturation ; survival
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Food concentration (0.5 × 103 − 5 × 105 Scenedesmus cells m1−1) significant influenced the somatic growth, maturation and survivorship ofS. proboscideus larvae. A density of 5 × 104 cells m1−1 was optimal for early larval stages. Of four temperature tested (20–35 °C), 30 °C resulted in the best growth and survival. Maturation time was inversely related to temperature, and was size- rather that age-dependent. Larvae were tolerant of a wide conductivity range, but optimal growth and survival were observed at 260 µS cm−1. Nitrate-Nitrogen (NO2-N) caused a larval mortality of 50% after 24 h at 0.58 mg1−1.
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  • 192
    ISSN: 1573-5117
    Keywords: Rutilus lemmingii ; age ; growth ; reproduction ; fecundity ; life-history tactics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The age, growth and reproduction ofRutilus lemmingii (Steindachner, 1866), an endemic cyprinid from the Iberian Peninsula, was studied for over a period of two years in a small seasonal tributary of the Guadalquivir river basin. Approximately 65 % of the total growth in length occured in the first year of life. Males reached a maximum age of 3+ yr (Fork Length, F.L. = 114 mm) and females 4+ yr (F.L. = 144 mm). Both sexes matured during their second year of life (1 +). The overall sex ratio (334 males to 389 females) differed significantly from unity. Somatic condition decreased markedly during the reproductive period of March to May.R. lemmingii is a multiple spawner and releases two batches of eggs per female each year. Mean egg diameter of the first batch was larger than the second one. The regression between fecundity and Fork Length (mm) was: Fec = 0.014 F.L.Z.2.858 Compared with available information, thisR. lemmingii population, located at a lower latitude, is characterized by fast growth, early maturity, high level of reproductive effort, and a short life-span. These life-history characteristices are typical of species in unstable environments, where adult mortality is high, variable or unpredictable.
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  • 193
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    Hydrobiologia 338 (1996), S. 163-172 
    ISSN: 1573-5117
    Keywords: lake smelt ; vendace ; bream ; pikeperch ; spawning ; fecundity ; feeding ; growth ; fisheries management
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Lake Peipsi is a large (3558 km2) and relatively shallow (up to 15.3 m) productive smelt-bream-pikeperch lake on the territories of Estonia and Russia. 34 fish and lamprey species inhabit this lake permanently, the main commercial fishes being smelt, perch, ruffe, roach, bream, pike, up to the 1990s also vendace and lately pikeperch. The second-rate commercial fishes are burbot, whitefish, white bream and bleak. In general, the spawning and feeding conditions of fishes are more or less favourable in the lake. Bream and pike grow fast, the majority of the other investigated fish species passably. The total catch of fish has usually been 9000–12000 t (25–34 kg ha−1) a year. As a result of the intensive use of trawls and fine-meshed Danish seines, the stock of pikeperch was strongly suppressed for a long time. After trawls were prohibited and the number of Danish seines considerably restricted, the stock and catches of pikeperch began to grow rapidly; pikeperch has become one of the main commercial fishes in the lake. During the last years the abundance of vendace has sharply decreased, and it has lost (we hope, temporarily) its economic importance. This is probably caused, first of all, by the high mortality of its eggs on the spawning grounds during successive mild winters of the last years. An increasing pressure from pikeperch (a big predator) has also contributed to strong decline of the stock of vendace. It would be reasonable to begin a regular introduction of elvers into the lake.
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  • 194
    ISSN: 1573-5117
    Keywords: Phragmites australis ; reed decline ; growth ; biomass allocation ; nutrient uptake ; eutrophication
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Performance of young Phragmites australis plants was examined after 7 weeks on an artificial nutrient-enriched inorganic substrate and on the same substrate to which an organic sediment from a eutrophic lake was added, at three different water depth treatments. Growth decreased, and proportional allocation of biomass to roots increased, with the addition of sediment. These differences were significant in shallow and deep water, but not at a medium depth. Concentrations of phosphorus and nitrogen in plant biomass decreased, and concentration of iron increased, with addition of sediment. The effects of sediment addition may have resulted from a decreased availability of nutrients in the substrate or from an impaired root functioning. Nutrient exhaustion in the substrate, due to a fast plant growth, can explain the relatively strong effects in shallow water. Deep water, on the other hand, probably restricted oxygen transport to the roots, resulting in an impaired root functioning in the low-redox sediment environment. The results show that, especially in relatively deep water, growth of undisturbed plants of P. australis may be inhibited by eutrophication of sediments, probably because of an impaired root functioning in sediments containing reduced toxic compounds (e.g. ferrous iron).
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  • 195
    ISSN: 1573-5117
    Keywords: Chironomus tentans ; growth ; emergence ; sediment toxicity assessment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A laboratory study was conducted with Chironomus tentans to assess the significance of growth retardation of third-to fourth-instar larvae over a 10-d test period on long-term survival, adult emergence, and ovipositing success. Data were intended to provide interpretive guidance for the commonly used growth endpoint in 10-d sediment bioassays with C. tentans. Larval growth was controlled by using six feeding levels ranging from 0.2 to 5.9 mg dry weight Tetrafin® fish food per day. Mean 10-d survival was ≥88% at all feeding levels, but larval growth decreased significantly (p〈0.05) with each decrease in feeding level. Cumulative successful emergence of adult C. tentans decreased significantly with decreasing larval growth. Mean times to emergence always increased with decreasing growth rates and effects were generally more pronounced for females than males. At the lowest 10-d mean growth where successful emergence occurred (0.27 mg), the times to emergence doubled relative to the times observed at the highest 10-d mean growth (1.03 mg). Ten-day larval growth retardation was strongly correlated with reduction in adult emergence success (r 2 = 0.96). Growth retardations ≥64% resulted in 86–100% reductions in adult emergence. Growth retardation in the range of 35 to 50% equated with comparable percent reductions in adult emergence success. Although fewer females successfully emerged at 10-d growths of 0.37 and 0.74 mg relative to the highest 10-d growth (1.03 mg), ovipositing success of these females did not appear to be adversely affected by either their slower growth rates or their lower mean dry weights (0.62 and 0.99 mg, respectively). Growth of second generation larvae did not appear to be affected by maternal growth rate, but rather appeared to be solely correlated with their own feeding level.
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  • 196
    ISSN: 1573-5117
    Keywords: exploitation rate ; recruitment ; mortality ; growth ; sex ratios
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Monthly length-frequency data of green tiger prawns from April 1985 to August 1990 were analyzed to estimate the von Bertalanffy growth curves and related parameters. The mean asymptotic carapace lengths (L ∞) and growth constants (K) over 5 seasons were 36.6 mm and 1.6 yr−1 for males and 51.2 mm and 1.7 yr−1 for females, respectively. Annual total mortality rates (Z) from 1985/86 to 1989/90 ranged from 2.7 to 6.5 yr−1 for males and from 2.8 to 6.8 yr−1 1 for females. The mean exploitation rates calculated using the mean natural mortality rates (M) of 2.5 yr−1 for males and 2.4 yr−1 for females showed that the male green tiger prawns in Kuwait waters were under exploited, whereas the catch of females was very close to the sustainable yield. Chi-square tests indicated that the sex ratio was close to one for adults (CL ≽ 26 mm), but significantly favoured males for recruits (CL 〈 26 mm). A major recruitment was detected from June/July in all seasons and a minor recruitment in some seasons in August/September. The relative yield-per-recruit (Y'/R) reached the optimum at the length-at-first capture (L c) of 25 mm CL for males, and increased as L c increased for females. The observed mean L c, values were 23.4 mm for both males and females. The Y'/R under the current exploitation level is close to the maximum sustainable yield for females, but lower for males. More fishing effort could be exerted to exploit males, but doing so may not be biologically or commercially possible with current trawling practices.
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  • 197
    ISSN: 1573-5117
    Keywords: Daphnia ; diapause ; growth ; maturity ; clutch size ; intrinsic rate of increase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Laboratory and field investigations revealed that the life history traits of exephippial and parthenogenetic generations of Daphnia differ substantially. Daphniids hatching from resting eggs grow faster and their definitive body sizes are bigger than of hatchlings from subitaneous eggs. Size at maturity for exephippial animals is significantly larger. In spite of this, they mature a few days earlier than parthenogenetic females. In this study, the difference was 3–4 days for the laboratory experiments and 1–3 days for the field. Fecundity of the exephippial generation is markedly higher. Here, the clutch size for this generation was up to 3.5–4.0 times as large as for the parthenogenetic generation. Moreover, obtained results suggest that the relationship between clutch size and body length for both generations differ significantly. Estimates of the intrinsic rate of increase for field Daphnia populations demonstrated that life history traits of exephippial animals lead to a two or threefold higher rate of increase in the conditions of invertebrate predation pressure. Under moderate fish pressure, obtained r values for the daphniids hatching from resting eggs were larger than those from subitaneous. High growth rate of exephippial females is disadvantageous only under the conditions of severe pressure by fish. Obtained results suggest that hatchlings from diapausing eggs an acceleration of population increase by several times during the beginning of the development of a population with periodical re-establishment from resting eggs.
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  • 198
    ISSN: 1573-5117
    Keywords: microcrustacean zooplankton ; tropical limnology ; laboratory cultures ; growth ; development rates ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Length growth, instar durations, fecundity and mortality rates of fivespecies of microcrustacean zooplankton from a tropical reservoir weremeasured in relation to food quantity and temperature in laboratorycultures. Three cladocerans (Ceriodaphnia cornuta, Moina micrura,Diaphanosoma excisum), one calanoid copepod (Heliodiaptomus viduus), and onecyclopoid copepod (Mesocyclops thermocyclopoides) were studied. Filteredseston (45 µm mesh) from a local pond was used for food. Two foodconcentrations were employed: (1) 10 µg chlorophyll l−1(ca 0.25 mg Cl−1), and (2) 50 µg chlorophylll−1 (ca 1.25 mg C l−1). Food levels and watertemperature (22.5, 27.5, and 32.5 °C) used, roughly covered the rangesfound in the reservoir. Although all the three growth parameters were oftenaffected to some degree by temperature and food, the quantitative responseof the species differed. Also, the species reacted differently to the threepossible interactions (i.e. food × temperature,food × instar, andtemperature × instar). This contributed to the overalldifferences in the species responses. For the cladocerans, instar durationswere always affected by temperature. The food did not affect the durationtime of the adults and that of the combined juvenile instars, the latterexcept in one case significantly. For the two copepods food level affectedthe duration times of naupliar and copepodite instars, but the effect oftemperature was only significant for H. viduus. The development timesobserved for H. viduus were extraordinary long compared with values reportedin the literature for other tropical calanoids. This suggests that foodconditions in our culture were adversely affecting its growth rates.
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  • 199
    ISSN: 1573-5117
    Keywords: Sediment bioassay ; Oligochaeta ; Tubifex tubifex ; Branchiura sowerbyi ; growth ; reproduction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Two tubificid oligochaetes, Branchiura sowerbyi and Tubifex tubifex, were evaluated as potential test organisms for sediment bioassays. We attempt to reproduce the sediment bioassay proposed by Reynoldson et al. (1991) using his strain of Tubifex tubifex and his reference sediment and to compare this technique using Branchiura sowerbyi. This species was chosen because it is more common and dominant in tropical and subtropical environments than Tubifex tubifex. Data on survival and reproduction were obtained for both species, and growth estimates were obtained for B. sowerbyi. The sublethal bioassay with T. tubifex confirmed earlier estimates of a test duration of 4 weeks at 22.5 °C. B. sowerbyi cultures can produce usable estimates in 21 days at 30 °C.
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  • 200
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    Hydrobiologia 334 (1996), S. 207-217 
    ISSN: 1573-5117
    Keywords: haplotaxids ; helical muscles ; ultrastructure ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract There are two different muscle fiber types in haplotaxids. The pseudo-circomyarian type is typical of Haplotaxis gordioides and the flattened circomyarian type of Pelodrilus leruthi. The mechanisms of growth in fiber size and in fiber number of the two fiber types in the hindmost region of adult specimens have been studied ultrastructurally. The increase in length and girth of the muscle fiber is always the result of the insertion of new myofilaments in the peripheral zones of the muscle cells. The increase in the number of fibers seems to be due to division of differentiated muscle cells.
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