Seasonal differences in the content of Oikopleura vanhoeffeni and Calanus finmarchicus faecal pellets: illustrations of zooplankton food web shifts in coastal Newfoundland waters

Faecal pellet contents from Oikopleura vanhoeffeni and Calanus finmarchicus were examined in the spring, summer, fall and winter.Contents varied seasonally, resembling available particles in the water column.This indicated a temporal succession from a diatom-based food chain in the winter and spring to one based on the microbial loop in the summer and fall.Bacteria, cyanobacteria, Anabaena sp., choanoflagellates, ciliates, and heterotrophic dinoflagellates were found in the faeces, suggesting a direct link between the microbial loop and both crustaceans and pelagic tunicates.