Feeding biology of Ophiura sarsii Lutken, 1855 on Banquereau bank and the effects of fishing

Ophiura sarsii was collected in May/June from Banquereau Bank off Nova Scotia, Canada as part of the benthic fauna analyzed in a 2 year clam dredging-impact experiment. In total, 529 O. sarsii specimens were analyzed; 174 (33%) had stomach contents while the rest were empty. Ophiura sarsii is a trophic generalist feeding on at least 31 taxa (52% identified to species) drawn from four phyla: Arthropoda (81.8%), Annelida (13.2%), Mollusca (3%), and Cnidaria (1.5%). However, the diet was largely restricted to two amphipod families (Ampeliscidae and Lysianassidae), accounting for 54-70% of stomach contents at any one sampling period. This diet provides indirect evidence for carnivory. Limited spatial and temporal heterogeneity in the proportion of animals feeding showed no consistent pattern. Where diet composition differed (ANOSIM) it was attributed to the proportion of lysianassid and ampeliscid amphipods consumed. Dredging introduced new dietary items, although diet composition was not significantly altered.