Food of winter flounder Pseudo-pleuronectes americanus in a sea urchin dominated community in eastern Newfoundland

Abstract

Gut contents were analysed from 63 winter flounder collected off eastern Newfoundland from rocky bottoms dominated by green sea urchins Stronglyocentrotus droebachiensis. Availability of prey items consumed was determined in the field. After removal from the analysis of items too large for the flounder to eat, and of those from cryptic microhabitats, it is evident that winter flounder are not selecting their food species. They do, however, select those prey items which are near the maximum size which they can consume, rather than the most abundant size. Predation by winter flounder may be large enought to influence the abundance of 2 important prey taxa, Metridium senile and Acmaea testudinalis. Comparison of gut contents of winter flounder from smooth and rough bottoms suggests that winter flounder predation on the green sea urchins themselves is unlikely to be improtant except on smooth bottom lacking cryptic microhabitat.