A new species of Pyropelta (Gastropoda: Pyropeltidae) from hydrothermal vents in the Okinawa Trough, southwestern Japan

Abstract

A new species of the genus Pyropelta (Pyropeltidae) was collected from hydrothermal vents in the Okinawa Trough, Japan. The generic assignment is confirmed by shell, radular morphology and several anatomical characters of the animal. Comparison of shell microstructural characters with other molluscs revealed possible new diagnostic characters of Pyropelta: (1) an irregular laminate sculpture associated with multiple insertion of thin prismatic sublayers, (2) a thick myostracum attaining whole shell thickness, (3) microtubules penetrating the myostracum completely and (4) internal position of shell growth front. At species level, P. ryukyuensis n. sp. is distinguished from other Pyropelta species by eight characters of the shell, shell microstructure and radula. © The Author 2008. Published by Oxford University Press on behalf of The Malacological Society of London, all rights reserved.