Aspects of the feeding biology of the brittle star Ophiura texturata

Abstract

Ophiura texturata was examined for its food habits at Ellekildehage in the Øresund and the Isefjord, Denmark. Food occurred in 51 % of the O. texturata examined from the Øresund and 55 % of the brittle stars from the Isefjord. The ophiurid ingests at least 41 small epifaunal and infaunal taxa, a variety of miscellaneous items, and sediment. Food analyses suggest that O. texturata is a potential predator of meiofauna, recently settled larvae, and small benthic macrofauna. In both areas, O. texturata utilized common, accessible prey items. In the Isefjord, where recently settled bivalve mollusks were numerous, the ophiurid fed intensively on them. Polychaetous annelids were also important in the latter area. Echinoderms, (primarily ophiurids), small crustaceans, and mollusks (gastropods, bivalves), in decreasing order of importance, were taken in the Øresund. The suggestion that omnivorous species such as O. texturata may be more destructive to newly settled young than are specialized predators, e.g. Natica spp, is reaffirmed. The potential importance of sediment and associated detrital material; items commonly observed in stomachs of O. texturata is discussed. No differences in feeding intensity by O. texturata in the Øresund were detected between spring, summer, and fall periods. A reduction in feeding occurred in winter.

Laboratory observations are presented for O. texturata on feeding behavior, prey acceptability, maximum size of food ingested, and retention time for food items ingested.