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Full-Text Articles in Life Sciences

Impact Of Bythotrephes Invasion On Zooplankton Communities In Acid-Damaged And Recovered Lakes On The Boreal Shield, Angela L. Strecker, Shelley E. Arnott Oct 2005

Impact Of Bythotrephes Invasion On Zooplankton Communities In Acid-Damaged And Recovered Lakes On The Boreal Shield, Angela L. Strecker, Shelley E. Arnott

Environmental Science and Management Faculty Publications and Presentations

Invasive species introductions into freshwater ecosystems have had a multitude of effects on aquatic communities. Few studies, however, have directly compared the impact of an invader on communities with contrasting structure. Historically high levels and subsequent reductions of acid deposition have produced landscapes of lakes of varying acidity and zooplankton communitystructure. We conducted a 30-day enclosure experiment in Killarney Provincial Park, Ontario, Canada, to test the effects ofBythotrephes longimanus, an invasive invertebrate predator, on two contrasting zooplankton communities at different stages of recovery from acidification: recovered and acid damaged. Bythotrephes significantly decreased zooplankton biomass and abundance in both communities but …


Daphnia Lumholtzi, An Exotic Zooplankton, Invading A Nebraska Reservoir, Brian C. Peterson, Nicolas J. Fryda, Keith D. Koupal, Wyatt Hoback Mar 2005

Daphnia Lumholtzi, An Exotic Zooplankton, Invading A Nebraska Reservoir, Brian C. Peterson, Nicolas J. Fryda, Keith D. Koupal, Wyatt Hoback

The Prairie Naturalist

A limnological assessment project by the University of Nebraska at Kearney and the Nebraska Game and Parks Commission collected weekly vertical zooplankton tows during May through September 2002 at Harlan County Reservoir in Nebraska. Beginning on 5 August 2002, the exotic Daphnia lumholtzi (Cladocera: Daphniidae) appeared at a density of 0.04 1.1 in one of fifteen standardized sampling stations. By 6 September 2002, D. lumholtzi was found in all fifteen stations at an average density of 2.17 ± 3.10 1.1 with a site maximum density of 11.43 1.1 • Length measurements of D. lumholtzi ranged from 0.80 mm to 5.66 …


The Role Of Feeding Behavior In Sustaining Copepod Populations In The Tropical Ocean, J. D. Wiggert, A. G. E. Haskell, G.-A. Paffenhofer, E. E. Hofmann, J. M. Klinck Jan 2005

The Role Of Feeding Behavior In Sustaining Copepod Populations In The Tropical Ocean, J. D. Wiggert, A. G. E. Haskell, G.-A. Paffenhofer, E. E. Hofmann, J. M. Klinck

CCPO Publications

A fundamental question regarding marine copepods is how the many species coexist and persist in the oligotrophic environment (i.e. Hutchinson’s paradox). This question is addressed with a stochastic, object-oriented Lagrangian model that explicitly simulates the distinct foraging behaviors of three prominent tropical species: Clausocalanus furcatus, Paracalanus aculeatus and Oithona plumifera. The model also individually tracks all prey cells. Each particle’s motion combines sinking, turbulent diffusion and active swimming when applicable. The model successfully simulates observed size partitioned carbon uptake rates. Based on the model results, the wide-ranging translational ambit employed by C. furcatus is best suited for the acquisition …


Zooplankton Of Two Drinking Water Reservoirs In Central Anatolia: Composition And Seasonal Cycle, Ni̇lsun Demi̇r Jan 2005

Zooplankton Of Two Drinking Water Reservoirs In Central Anatolia: Composition And Seasonal Cycle, Ni̇lsun Demi̇r

Turkish Journal of Zoology

Comparative studies were performed on the zooplankton composition and some physical and chemical properties of the Kurtboğazı and Çamlıdere reservoirs. Zooplankton abundance, conductivity, organic matter, hardness and orthophosphate concentrations were lower and Secchi depth was higher in Çamlıdere than in Kurtboğazı (P < 0.01). Rotifera species such as Polyarthra dolichoptera, Keratella quadrata, Asplanchna priodonta and Ascomorpha saltans showed peaks, particularly in spring, summer and late summer. Diaphanosoma lacustris, Bosmina longirostris and Ceriodaphnia quadrangula of Cladocera species increased in late summer whereas Bosmina longirostris and Daphnia spp. were prominent in spring. The cyclopoid copepod Cyclops vicinus was dominant in Kurtboğazı and calanoid Acanthodiaptomus denticornis in Çamlıdere.