FEEDING OF ONCAEA-CURVATA (POECILOSTOMATOIDA, COPEPODA)

Oncaea curvata is one of the dominating copepod species of the Antarct ic 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 ecos ystem. The experiments of this study show that O. curvata females pref er large, nonmotile food particles such as aggregates or gelatinous Ph aeocystis colonies. Up to 18% of their body carbon was ingested daily from a Phaeocystis cf, pouchetii culture at natural concentrations, an d up to 35 % from a Phaeocystis bloom, which consisted of gelatinous c olonies with other flagellate species and diatoms. The highest ingesti on rates of about 300 % of their body carbon per day were measured whe n feeding on a Phaeocystis bloom at higher than ambient concentrations . Diatoms were an acceptable food as well. The daily carbon uptake amo unted to 2-26% of O. curvata's body carbon at natural chlorophyll a co ncentrations. Accordingly this species may have as much influence on p hytoplankton stocks as calanoid copepods. In contrast to many other On caeidae, O. curvata females were not carnivorous and did not feed on m otile food (copepods or flagellates).