Description of a New Deep-Water Calcareous Sponge (Porifera: Calcarea) from Northern California

Abstract

A new species, Sycon escanabensis Duplessis & Reiswig, is described from material retrieved by submersible from 3500 m depth in the Escanaba Trough, central Gorda Ridge, off northern California. The species differs from all other members of the genus by the combination of conspicuous tripartite body organization and slender, lancet-head diactins that ornament the external surface and the oscular margin. This is the first deep-water (> 1000 m) calcareous sponge described from the North Pacific Basin.