Webbläsaren som du använder stöds inte av denna webbplats. Alla versioner av Internet Explorer stöds inte längre, av oss eller Microsoft (läs mer här: * https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Var god och använd en modern webbläsare för att ta del av denna webbplats, som t.ex. nyaste versioner av Edge, Chrome, Firefox eller Safari osv.

Size-selective predation on pelagic microorganisms in Arctic freshwaters

In English

Författare

Summary, in English

Herbivorous zooplankton may have a pronounced influence on pelagic microorganisms in Arctic freshwaters. We quantified experimentally the size-selective feeding of several zooplankton groups on pelagic microorganisms in high Arctic tundra systems. Our experiments and field study focused on dominant herbivores in Arctic freshwaters, including the cladoceran Dophnia, the copepod Diaptomus and the anostracan Branchinecta, and their effects on prey ranging in size from bacteria to large phytoplankton. Grazing experiments showed that Dophnia were effective predators on all types of prey, whereas Diaptomus grazed preferentially on larger phytoplankton with low clearance rates for bacterial cells. Further analysis by flow cytometry indicated that Diaptomus grazed selectively on the largest bacteria. In contrast to the results obtained in the controlled experiments, Arctic lakes and ponds with a zooplankton community dominated by Dophnia had a higher bacterial production and abundance than systems not dominated by this grazer. This may indicate that the stimulatory effect of grazers on bacterial growth is more pronounced in natural systems, or that factors other than zooplankton grazing are more important in regulating bacterial abundance and production in natural systems. Although Arctic waters differ considerably from temperate systems with respect to temperature and light regime, herbivore-prey dynamics as well as the bacterial response to temperature appear to be similar between the climatic regions.

Publiceringsår

2003

Språk

Engelska

Sidor

621-631

Publikation/Tidskrift/Serie

Journal of Plankton Research

Volym

25

Issue

6

Dokumenttyp

Artikel i tidskrift

Förlag

Oxford University Press

Ämne

  • Ecology

Status

Published

Forskningsgrupp

  • Aquatic Ecology

ISBN/ISSN/Övrigt

  • ISSN: 0142-7873