Wikipedia
Alviniconcha
Alviniconcha is a genus of deep water sea snails, marine gastropod mollusks in the family Provannidae. These snails are part of the fauna of the hydrothermal vents in the Indian and Western Pacific Ocean. These and another genus and species within the same family ( Ifremeria nautilei) are the only known currently existing animals whose nutrition is derived from an endosymbiotic relationship with proteobacteria: a member of bacteria from class Epsilonproteobacteria occurs as an endosymbiont of the gills of Alviniconcha hessleri.