Prochaetodermatidae of the Indian Ocean collected during Soviet VITYAZ cruises 1959–1964 (Mollusca : Aplacophora)

Abstract

Four new aplacophoran mollusc species of Prochaetodermatidae (Prochaetoderma arabicum n. sp., Chevroderma lusae n. sp., Chev. javanicum n. sp., and Chev. vityazi n. sp.) and three new records (Chev. turnerae Scheltema, Chev. paradoxum Ivanov & Scheltema, Claviderma laticarinatum Ivanov & Scheltema) are added here to those described earlier for the western Indian Ocean and Arabian Sea and Atlantic Ocean. One of the species, the abyssal Chev. turnerae, is cosmopolitan throughout the Atlantic Ocean and is here reported from the eastern and western Indian Ocean. Prochaetoderma arabicum n. sp. is the only species in the genus Prochaetoderma that has been collected in the Indian Ocean/Arabian Sea. Two eastern Indian Ocean species, both with a curiously long narrow posterium, are superficially similar; one, Chev. javanicum, occurs at hadal depths in the Java Trench and the other, Chev. vityazi, was collected from the lower continental slope. So far, no prochaetodermatid species has been collected from the Indian Ocean at depths less than 1000 m.