The ecology and reproductive biology ofCherbonniera utriculusandMolpadia blakeifrom the N.E. Atlantic

Abstract

The Molpadiida is an order of sea cucumbers identified by their stout body, the posterior region narrowing to simulate a tail and the absence of tubefeet. Typically they inhabit muddy environments from shallow water to abyssal depths. In the past the great variability in the taxonomic characters of this order has led to the formation of many genera and species (Heding, 1931, 1935), but more recently it has become apparent that many diagnostic characters change markedly during the life history of these holothurians and as a result fewer species are now recognised (Deichmann, 1940; Pawson, 1977). In a revision of the Atlantic molpadiids Deichmann (1940) recorded just three species from the north-east Atlantic (Molpadia blakei, M. musculusandHedingia albicans)with a further three species from the Arctic Ocean and Norwegian Sea (M. arctica, M. borealisandEupyrgus scaber). To these Sibuet (1974) added the new genus and speciesCherbonniera utriculusfound in the Bay of Biscay.