Molluscan diversity in shallow water hydrothermal vents off Kueishan Island, Taiwan

Abstract

Hydrothermal vents are among the most ‘extreme’ habitats in the marine ecosystem, with increased water temperature, drastically different pH to the surrounding water, and richness in toxic substances such as hydrogen sulphide and methane. Although perhaps better recognised as deep-sea habitat, vents actually occur in shallow water within SCUBA diving range in various parts of the world. Kueishan Island, Taiwan is one location where these shallow vents occur, and with a pH as low as 1.52 it is one of the most ‘extreme’. Although the faunal composition of shallow Kueishan vents have been previously reported, some molluscan species, however, were misidentified. Here we present a corrected and updated list of molluscs inhabiting hydrothermally influenced areas off Kueishan Island, a total of 13 species including six new records. Documentation of biodiversity is key in understanding ecosystem functioning, and we briefly discuss the potential significance of the apparent abundance of carnivorous and suspension feeding molluscs in Kueishan vents.