 Bivalves inhabit the tropics , as well as temperate and boreal waters . A number of species can survive and even flourish in extreme conditions . They are abundant in the Arctic , about 140 species being known from that zone . The Antarctic scallop , Adamussium colbecki , lives under the sea ice at the other end of the globe , where the subzero temperatures mean that growth rates are very slow . The giant mussel , Bathymodiolus thermophilus , and the giant white clam , Calyptogena magnifica , both live clustered around hydrothermal vents at abyssal depths in the Pacific Ocean . They have chemosymbiotic bacteria in their gills that oxidise hydrogen sulphide , and the molluscs absorb nutrients synthesized by these bacteria . The saddle oyster , Enigmonia aenigmatica , is a marine species that could be considered amphibious . It lives above the high tide mark in the tropical Indo @-@ Pacific on the underside of mangrove leaves , on mangrove branches , and on sea walls in the splash zone . 
