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Showing 1 to 20 of 126 for “"copepods"”.
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The ecology of some Harpacticoid copepods of a California sand flat
… ecology of eight species of harpacticoid copepods over a period of one year with emphasis on the effects of physical interactions and biotic factors on these populations. The species were: Amphiascopsis sintus (Claus) 1866, Stenhelia (D.) oblonga Lang, 1965, Heterolaphote variables Lang, …
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From single species to mesocosms: responses of freshwater copepods and their community to PCP
… C. lucasi was the most sensitive of the three copepods with 48 h LC50 values of 52 and 106 μg.L⁻¹ PCP for nauplii and adults respectively. B. delicata nauplii and M. leuckarti adults were least sensitive (227 and 173 μg.L⁻¹ respectively). Summer collected C. lucasi adults at 22°C were least …
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Temperature impact on reproduction and development of congener marine copepods: a key to distribution patterns?
The life cycles of four copepod species of the genera Temora and Centropages, which differentiate in their geographical and/or seasonal distribution patterns, were investigated particularly with regard to temperature effects on population dynamics and distribution. In the field, reproduction was …
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Biodiversity assessment of groundwater-dependent ecosystems in Malta : evaluating copepods as bioindicators of groundwater health
… ecosystems (GDEs) in Malta, focusing on copepods as bioindicators of groundwater health. Groundwater is essential in sustaining GDEs, yet these ecosystems remain underexplored, particularly in terms of local biodiversity. The aim of this research is to assess the biodiversity of …
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The pelagic copepods of Lambert's Bay : an ecological study of a west coast fishing ground
… ratios. Among the zooplankton, copepods were singled out for special attention because of their importance as food for larval fish. Only six species comprised 83% of the copepod community. These species displayed different spatial and temporal distribution, which appeared to be …
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Comparative ecology of the copepods calanoides carinatus and calanus agulhensis in the Southern Benguela and Agulhas Bank ecosystems
The aim of this study was to investigate the niche separation between these two species, using zooplankton net samples collected during biannual hydroacoustic surveys of pelagic fish between 1988 and 2000, as well as results from ship- and laboratory-based egg production and feeding experiments. C. …
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Temporal and spatial changes in the abundance and size structure of copepods in the southern Benguela : 1988 to 2000
… in abundance and community structure of copepods in the southern Benguela, by estimating changes in abundance (No. mol) of individual species and size-classes. The relative abundance of Calanus agulhensis, Calanoides carinatus, Centropages brachiatus, Metridia lucens. Oithona spp., On cae …
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Genetic diversity and structure of calanoid copepods: Molecular evolutionary patterns in coastal estuaries (Acartia tonsa) and the open ocean (Calanus spp)
<p>Calanoid copepods are an important part of marine and estuarine ecosystems. However, it has been difficult to study their life histories, population structure, and evolution because they share a conserved morphology that complicates species identification. A primary focus of this study was the …
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Seasonal and spatial distribution of the mesozooplankton of Southampton Water with particular reference to the contribution of copepods and barnacle larvae to pelagic carbon flux
… of the major components and identifying calanoid copepods and barnacle larvae as the major elements. Despite the number of studies, almost all knowledge about species composition, dominance and succession patterns of the mesozooplankton as a whole, is described from only a few studies, usually …
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Food Selectivity of Bigmouth Buffalo (Ictiobus cyprinellus, Valenciennes) in Lake Poinsett, South Dakota
… comprised 68.5% by volume and cyclopoid copepods 29.7%^ of the diet from April to July. Summer (July to October) samples showed ingestion of D. pulex adults and juveniles (36.9%), Anacystis sp. (22.3%), and Daphnia galeata mendotae (16.0%). Fall (October) samples showed ingestion of D. …
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Biological control of Culex mosquitoes using multiple predators
… the management of vector mosquito populations. Copepods have been particularly successful biocontrol agents for mosquitoes. However, the efficacy of biological control agents is mediated by context-dependencies, which are often poorly understood. A functional response (FR) approach is frequently …
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Variability of copepod abundance and growth in the southern Benguela upwelling system and implications for the spawning of the Cape anchovy
… strategy requires continual ingestion of copepods, which dominate the diet of anchovy at this time. This thesis investigates the spatial and temporal variability of copepod abundance and growth, and their impact upon the spawning of anchovy. Sampling was conducted monthly between …
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Interactions between calanoid copepod hosts and their associated microbiota
Zooplankton, such as copepods, are highly abundant environmental reservoirs of many bacterial pathogens. Although copepods are known to support diverse and productive bacterial communities, little is understood about whether copepods are affected by bacterial attachment and whether they can …
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An investigation of the growth and feeding responses of oligotrich ciliates to food types and concentrations : an approach to assessing the potential of marine planktonic ciliate blooms
… in a non-steady state, where ciliates and copepods encountered a patch of water with a defined initial algal concentration. The model indicated: 1) ciliates bloom over 10-20 d, when copepods are rare (<1 L4) and algae are initially abundant (>103 mL4); 2) ciliate blooms can provide 40-50% …
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The relative role of protozoans in the flux of phytoplankton nitrogen through pelagic food webs
… microplanktonic compartments leading to copepods. Uptake of nitrate and ammonium by three different size classes of phytoplankton (net-, nano-, and picoplankton) was measured using ¹⁵N isotope techniques. Microzooplankton grazing on autotrophic picoplankton and nanoplankton was quantified …
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Parasite abundance in Atlantic cod (Gadus morhua) in shallow and deep waters around Iceland
… I found that certain groups of parasites like copepods, nematodes and acanthocephalans appear to infect the ecotypes differently in terms of abundance and diversity of parasites. Deep-water cod had a mean abundance of 95.2 (SD = 68.4) nematodes, 2.2 (SD = 2.17) acanthocephalans and 3.8 (SD = …
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Distribution of Free Marine Viruses of Lower Chesapeake Bay and Their Effects on Life-History Parameters of the Estuarine Copepod <i>Acartia tonsa</i> Dana
… egg hatching success, and mortality of copepods were measured. Elevated VLP concentrations were obtained by concentrating the virus-size fraction of fresh seawater or water from copepod cultures. Across six experiments, no detrimental effects of viruses on copepods were demonstrated. …
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Feeding Ecology of Fishes in a South Dakota Power Plant Cooling Reservoir
… spp., while they negatively selected cyclopoid copepods, Ceriodaphnia spp., and Tanypodinae larvae. Chironomid larvae were positively selected by bluegills mm, but were negatively selected by those >50 mm. Fishes and chironomid larvae were the major food items of 105 black bullheads >120 mm TL; …
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