THYASIRIDAE (MOLLUSCA: BIVALVIA) FROM THE KEMP CALDERA HYDROTHERMAL SITE, SOUTH SANDWICH ISLANDS, ANTARCTICA

摘要

Two species of thyasirid bivalve are described from the Kemp Caldera hydrothermal site, South Sandwich Island back arc system, Antarctica. Spinaxinus caldarium n. sp. is chemosymbiotic and closely related to S. emicatus from the Gulf of Mexico with which it shares the same phylotype of symbiotic bacterium. Parathyasira cf. dearborni is not symbiotic and most closely resembles P. dearborni a widespread circum antarctic species. The gill anatomy is described for both species and molecular data on the bivalves and the symbiotic bacteria are presented.