|Hirtopelta tufari sp. n., a new gastropod species from hot vents at the East Pacific Rise (21° S) harbouring endocytosymbiotic bacteria in its gill (Gastropoda: Rhipidoglossa: Peltospiridae)|
Beck, L.A. (2002). Hirtopelta tufari sp. n., a new gastropod species from hot vents at the East Pacific Rise (21° S) harbouring endocytosymbiotic bacteria in its gill (Gastropoda: Rhipidoglossa: Peltospiridae). Archiv. Molluskenkd. (2004) 130(1-2): 249-257, 17 figures
In: Archiv für Molluskenkunde (2004). Schweizerbart: Stuttgart. ISSN 1869-0963, more
A new limpet-shaped deep sea gastropod, Hirtopelta tufari sp.n., is examined in this study. Eleven specimens of the new taxon were collected from hot vent sites with active "blacksmokers" at the East Pacific Rise (21°S, 2802 m depth) during the German OLGA I-cruise in 1989. Based on morphological evidence of the shell, the soft parts, and the radula the new species is distinguished from the sister taxon Hirtopelta hirta McLean 1989 and assigned to the Peltospiridae. In comparison to other archaeogastropods, the gill is transformed and extremely enlarged showing two cell-layers of bacteriocytes at the gill leaflets. Histological evidence based on transmission elektron microscopy revealed numerous oval-longish, probably non-methanotrophic microorganisms of 0.5 µm length and 0. 1 5 µm diameter. These bacteria are arranged in vacuoles in the outer two thirds of the bacteriocytes. The highly specialized endocytosymbiosis, the unusual dimension of the gill as well as sampling from Alvinella-tubes at active black smokers let us assume that the nutrition of Hirtopelta tufari sp.n. relies almost entirely on the support of endosymbiotic bacteria.