Polynoid polychaetes of the Mid-Atlantic Ridge and a new holothurian association

Presented here is a new deep-sea association between the polynoid, Eunoe bathydomus (Ditlevsen, 1917) and the holothurian Deima validum validum Theel, 1879 from the Mid-Atlantic Ridge, North Atlantic. For the first time in the deep-sea two polynoid specimens have been found on a single holothurian host. Genetic data in this study show that E. bathydomus has a distribution ranging across the Mid-Atlantic Ridge over a distance of 72 km, which could have been facilitated by hitchhiking on holothurians, although the main ecological benefits for being associated with a host remain unclear. Additional taxonomic records of polynoid species recovered during remotely operated vehicle Isis sampling during the RRS James Cook cruise JC48 in summer of 2010 are also presented.