NAKED IN TOXIC FLUIDS - A NUDIBRANCH MOLLUSK FROM HYDROTHERMAL VENTS

A new species of the nudibranch genus Dendronotus (Mollusca, Opisthobr anchia) is reported from a hydrothermal vent at the Lucky Strike area, on the Mid-Atlantic Ridge. This is the first species of nudibranch re corded with certainty from a vent site. Other species of Dendronotus a re distributed in temperate waters on the continental shelf of the nor thern hemisphere. Two factors that probably account for the occurrence of a nudibranch in this hydrothermal field are that the Lucky Strike area presents potential hydroid prey, and that nudibranchs apparently inhabit a lower activity area. It is hypothesized that the new species , which lacks eyes, is a permanent resident of vent fields on the Mid- Atlantic Ridge, but is probably not restricted to that environment. (C ) 1998 Elsevier Science Ltd. All rights reserved.