CORALLIOPHILINE DIVERSITY AT MID-ATLANTIC SEAMOUNTS (NEOGASTROPODA, MURICIDAE, CORALLIOPHILINAE)

摘要

Eleven species of the Coralliophilinae were identified on seamounts of the NE Atlantic and in the Azores. The species-level taxonomy is reviewed with emphasis on the protoconch species-specific characters. The Meteor group of seamounts yielded six species (plus two unidentified), with 3-6 species found sympatrically. Babelomurex atlantidis is described as new, Coralliophila aedonia (Watson, 1886), Babelomurex sentix (Bayer, 1971) and B. dalli (Emerson and D'Attilio, 1963) are reported for the first time in the mid-North Atlantic. Species which were found either abundant (C. aedonia, B. sentix, B. atlantidis) or reproducing (B. dalli) are assumed to form established populations on the mid-Atlantic seamounts. In the Lusitanian group of seamounts only Gorringe yielded more than one species; all species are shared either with the European mainland or with the Canary Islands, and there is no evidence for established populations. The coralliophiline species found on the seamounts showed evidence of planktotrophic larval development; at least two are amphiatlantic, which illustrates the role of the seamounts as stepping stones in transoceanic dispersal. Some species are not known outside the seamounts, but this may be explained by the increased availability of bathyal hard bottoms rather than by limitations to dispersal.