Oasisia sp. SBJ-2009 is a species of tube worm in the family Siboglinidae, found in deep-sea hydrothermal vents and cold seep ecosystems. This species thrives in extreme environments by relying on a symbiotic relationship with sulfide-oxidizing bacteria housed in its trophosome, a specialized organ. These bacteria convert hydrogen sulfide into organic compounds, providing the worm with essential nutrients. Oasisia sp. SBJ-2009 plays a crucial role in deep-sea ecosystems by contributing to nutrient cycling and supporting diverse microbial and faunal communities.