Inter-Research > MEPS > v262 > p193-200  
Marine Ecology Progress Series

via Mailchimp

MEPS 262:193-200 (2003)  -  doi:10.3354/meps262193

Feeding of Calanus finmarchicus nauplii in the Irminger Sea

Xabier Irigoien1,*, Josefin Titelman2,4, Roger P. Harris2, Derek Harbour2, Claudia Castellani3,5

1AZTI (Fisheries and Food Technological Institute), Herrera Kaia Portualdea, 20110 Pasaia, Spain
2Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK
3Southampton Oceanography Centre, European Way, Southampton SO14 3ZH, UK
4Present address: Department of Fisheries and Marine Biology, University of Bergen, Bergen 7800, 5020 Norway
5Present address: Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK

ABSTRACT: Recent studies have shown that the passage from nauplius to copepodite is a key event in the population dynamics of Calanus finmarchicus. As a first step towards understanding if and how trophic interactions influence this event, we investigated the feeding of C. finmarchicus nauplii IV-VI in the Irminger Sea during spring and summer in a series of incubation experiments. Generally, feeding efficiencies were highest on large cells, whereas small flagellates were ingested at very low rates. Colonies of Phaeocystis sp. were not ingested. Among the larger cells, the diatoms Chaetoceros pelagicus and Tropodineis sp. and the ciliate Strombidium sp. were the main food sources. We observed a negative relationship between the percentage of diatoms in the food environment and the filtration rate on Strombidium sp. We therefore suggest that the combination of low feeding efficiency on small cells and the generally low concentrations of ciliates in oceanic waters explains why C. finmarchicus relies on phytoplankton blooms for recruitment from nauplius to the first copepodite stage.

KEY WORDS: Calanus finmarchicus nauplii · Feeding · Phytoplankton · Microzooplankton

Full text in pdf format