New insights on elasipodids and dendrochirotids from South Western Atlantic Ocean (0-3500 m).

MARIANO IGNACIO MARTINEZ; PABLO ENRIQUE PENCHASZADEH

Conferencia; 15 th International Echinoderm Conference; 2015

In the last decade new species reports of echinoderms has been increasing exponentially, and particularly for South Atlantic the production of new reports has been more and more common. Since 2009 extensive benthic faunal explorations has been conducted on board the O/V Puerto Deseado from Argentina, which allow shallow and deep-sea sampling. New fauna has been discovered and echinoderms, in particular holothurians, where not the exception. From the first look and beyond, in Elasipodida and Dendrochirotida were the most important discoveries, with new fauna and distribution extensions for the South Western Atlantic Ocean. After 3 deep-sea cruises, last year was described a new elasipodid, Benthodytes violeta. This species has eigth dorsal appendages up to the half of the body and ossicles compose by crosses with three and four arms and primary crosses with central bipartite apophysis. Some specimens belonging to family Elpidiidae have been identified and others belonging to Scotoplanes genus at 3000 m in front of Argentine coast. While Elasipodida show deep-sea new reports, dendrochirotids reports were more extended, from shallow to deep-sea waters. Apart from the already known new genus and species Thandarum hernandezi and the new species Havelockia pegi from Argentine shallow waters, there were identified some specimens of Psolus patagonicus up to 500 m and Cladodactyla crocea up to 1000 m. These both species has been reported from shallow waters and probably deserve molecular studies for this extent distribution, in particular for been known as brooders. Also for Psolidae, Psolus murrayi was identified which the only description was from Théel in 1886.