Crinitostella laguardai, new genus and species of wood-dwelling deep-sea sea-star (Asteroidea: Caymanostellidae) from the Gulf of Mexico

Abstract

The Caymanostellidae is a family of rarely encountered wood-dwelling deep-sea sea-stars, with only six species, in two genera, described to date. During the COBERPES 5 expedition on board the RV ‘Justo Sierra’, off Tabasco, Gulf of Mexico in 2013, 12 specimens were recovered from a single piece of sunken wood. Herein we describe a new genus and species of caymanostellid, Crinitostella laguardai gen. nov., sp. nov. This species represents the shallowest known caymanostellid (418–427 m depth), and the first known occurrence of the Caymanostellidae from the Gulf of Mexico. The family Caymanostellidae displays affinities with several groups, such as Asterinidae and Korethrasteridae, making it difficult to infer its phylogenetic position evidenced by the myriad of contrasting phylogenetic hypotheses proposed. In an attempt to shed some light on the phylogenetic relationships of the family, sequences of nuclear and mitochondrial DNA of the new species were generated and combined with published data. As previously suggested, caymanostellids seem to be part of valvatacean polytomy rather than velatids.