The diet of Ophiosparte gigas (Echinodermata: Ophiuroidea) along the Antarctic Peninsula, with comments on its taxonomic status

Analyses of stomach contents of 121 adult Ophiosparte gigas Koehler 1922, collected along the western coast of the Antarctic Peninsula in 1981–1983, show that this species is an active predator and scavenger whose diet consists of representatives of at least 10 phyla. The top five prey groups are sponges, ophiuroids, bivalves, polychaetes and crustaceans by percentage frequency of occurrence, and ophiuroids, bivalves, polychaetes, amphipods and sponges by fullness relative volume. Rankings of prey by various frequency and volume measures vary among different sites suggesting that Ophiosparte gigas is an opportunistic feeder. Significant differences in diet, feeding behavior and morphological characteristics related to feeding, and others, including composition of the integument and structure of the oral and dental plates, show the conventional placement of the monotypic genus Ophiosparte in the Ophiacanthidae is not justified. We suggest placement in the Ophiomyxidae but formal designation within a subfamily must await a thorough revision of the suborder Ophiomyxina.