First record of the sponge genera Crambe and Discorhabdella for the eastern Pacific, with description of three new species

Abstract

Three new sponge species are described from the Pacific coast of Panama, namely Crambe panamensis n. sp., Discorhabdella urizae n. sp. and Discorhabdella littoralis n. sp. This is the first record of the genera Crambe and Discorhabdella for the eastern Pacific, which represents not only a considerable expansion in their known biogeographical distribution, but also empirical support for their Tethyan origin. The new species provide a better understanding of the skeletal evolution in these peculiar genera, representing a lineage in which aster-derived spicules occur within a typical poecilosclerid skeleton. The skeleton of C. panamensis consists of ectosomal subtylostyles, choanosomal tylostyles with smooth tyle, basal desmas of astroclone type only, and anchorate isochelae. The skeleton of D. urizae consists of ectosomal subtylostyles, choanosomal tylostyles with tuberose tyle, basal acanthostyles with aster-like tyle, anchorate isochelae, sigmas, and distinctive twisted microxeas. The skeleton of D. littoralis consists of ectosomal tylostyles, choanosomal tylostyles that occasionally show remains of tubercles in the tyle, basal acanthostyles with a tyle intermediate between aster-like and regular morphology, and sigmas. The skeletal affinities of Crambe and Discorhabdella with the genera Lithochela and Monanchora are discussed, and a new family concept based on all four genera is proposed. The name Crambeidae is proposed for such a family, to replace the pre-occupied name Crambidae.