Synopsis of the deep-sea groups of Triphoroidea (Gastropoda)

Abstract

ABSTRACTThe marine gastropod superfamily Triphoroidea is composed of three families: Triphoridae and Cerithiopsidae are usually associated with shallow waters, and Newtoniellidae is historically associated with the deep sea. We provide an extensive review of the literature and delineate the groups within the three families that are truly linked to the deep sea, with reference to their developmental mode. Two genera of Triphoridae, Strobiligera and Inella, are commonly found in deep waters, and Metaxia presents some species with apparently wide depth ranges. Some deep-sea genera currently placed in Cerithiopsidae, such as Ektonos and Krachia, are very similar to Newtoniellidae; a phylogeny of the superfamily is needed to clarify the distinction of the two families. The majority of Triphoroidea species from the deep sea undergo non-planktotrophic development, although planktotrophy is not uncommon.