ABSTRACT: Oncaea curvata is one of the dominating copepod species of the Antarctic in terms of numbers, and in the vicinity of the shelf often also in terms of biomass. However, little is known about its role in the ecosystem. The experiments of this study show that O. curvata females prefer large, non-motile food particles such as aggregates or gelatinous Phaeocystis colonies. Up to 18% of their body carbon was ingested daily from a Phaeocystis cf. pouchetii culture at natural concentrations, and up to 35% from a Phaeocystis bloom, which consisted of gelatinous colonies with other flagellate species and diatoms. The highest ingestion rates of about 300% of their body carbon per day were measured when feeding on a Phaeocystis bloom at higher than ambient concentrations. Diatoms were an acceptable food as well. The daily carbon uptake amounted to 2-26% of O. curvata's body carbon at natural chlorophyll a concentrations. Accordingly this species may have as much influence on phytoplankton stocks as calanoid copepods. In contrast to many other Oncaeidae, O. curvata females were not carnivorous and did not feed on motile food (copepods or flagellates).

KEY WORDS: Copepod · Oncaea curvata feeding · Antarctic

Published in MEPS Vol. 169 (1998) on August 6
ISSN: 0171-8630. Copyright © Inter-Research, Oldendorf/Luhe, 1998