ИСТИНА

From four currently known starfishes of the family Caymanostellidae established by Belyaev (1974) based on 13 specimens found on sunken wood collected from the Cayman Trench, Caribbean Sea at the depths 6740-6780 m. and all referred to a new species Caymanostella spinimarginata Belyaev, 1974, only this species, C. spinimarginata, is known from the Atlantic Ocean, the others are recorded from the Indian Ocean and South Pacific. Three specimens of Caymanostella were recently sampled on sunken wood along with other taxa associated with this special habitat during the joint German–Russian expedition KuramBio II from the abyssal plain adjacent to the Kuril-Kamchatka Trench at the depths 5101–5134 m. Surprisingly, these new specimens were very similar to the C. spinimarginata, the most geographically distant species. Comparison of the KuramBio II specimens and the type material of C. spinimarginata showed that they share the main morphological characters of this species. Some differences occured rather point at intraspecific than interspecific variability. Multi-gene molecular data was obtained for the enigmatic family Caymanostellidae for the first time due to a good preservation of the KuramBioII specimens (only single 595 bp fragment of 16S rRNA gene was known for Caymanostella sp. up to date). Preliminary phylogenetic analyses of ribosomal COI and 16S rRNA, and nuclear 18S rRNA gene sequences (total length ~3123 bp) place caymanostellids into a basal polytomy among representatives of six orders of the class Asteroidea. Thus, additional data from other genetic markers is needed to clarify the phylogenetic position of the family Caymanostellidae.