Brittle stars (Echinodermata: Ophiuroidea) from seamounts in the Andaman Sea (Indian Ocean): first account, with descriptions of new species

Abstract

Brittle stars were collected on two seamounts in the Andaman Back-arc Basin. Of the six species, two were new to science and are described herein as Ophioleuce longispinum sp. nov. and Ophiophyllum minimum sp. nov., in the family Ophiuridae, subfamilies Ophioleucinae and Ophiurinae, respectively. Skeletal details were studied and documented by scanning electron microscopy. Morphological similarities between related species are discussed in detail. Ophioleuce longispinum sp. nov. is particularly interesting, because it combines characters typical for its genus with those otherwise only known from Ophiophyllum, such as a limpet-like disc, a fringe of marginal disc papillae or spines, and a paddle-like modified lower arm spine. The remaining species, Astrophiura cf. tiki, Ophiactis perplexa, Ophiolimna antarctica and an unidentified Ophiura, are new records for the Andaman Sea.