Feeding of Calanus finmarchicus and Oithona similis on the microplankton assemblage in the Irminger Sea, North Atlantic

Claudia Castellani, Xabier Irigoien, Daniel Justin Mayor, Roger P. Harris, David Wilson

Research output: Contribution to journalArticle

44 Citations (Scopus)

Abstract

The present investigation reviews published data on the feeding rates and prey selection of Oithona similis females, Calanus finmarchicus nauplii and females in the Irminger Sea in April/May and July/August 2002. Our aim was to examine how the feeding rates and prey selection of these three copepod stages respond to concomitant changes in microplankton community composition and prey abundance. Copepods typically ingested prey overall according to its ambient concentration although significant species and stage-specific differences in prey-type ingestion and selection were apparent. Despite being of comparable weight, the ingestion rates of C. finmarchicus nauplii were always higher than those of the O. similis females. Moreover, C. finmarchicus nauplii and O. similis females fed preferentially on diatoms and ciliates respectively, whereas adult female C. finmarchicus showed limited prey selectivity. Copepod grazing impact on total and on ciliates/dinoflagellates standing stock was < 0.5 and < 2%, respectively. We attribute this result to a combination of low grazing rates, low copepod abundance and low microplankton biomass, all of which are indicative of the non-bloom conditions under which these experiments were conducted. The differences in copepod feeding rates and prey selection we report reflect species and stage-specific eco-physiological adaptations, which may act as important driving forces for marine ecosystem structuring and functioning.

Original languageEnglish
Pages (from-to)1095-1116
Number of pages22
JournalJournal of Plankton Research
Volume30
Issue number10
Early online date23 Jul 2008
DOIs
Publication statusPublished - Oct 2008

Keywords

  • copepod acartia-tonsa
  • marine ecosystems
  • egg-production
  • trophic interactions
  • coastal waters
  • cell-volume
  • West-Coast
  • phytoplankton
  • predation
  • prey

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