Onoba grisea is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae. Distribution Description The maximum recorded shell length is 2.52 mm. Habitat Minimum recorded depth is 0 m. Maximum recorded depth is 102 m. References Ponder, W. F. (1983) Rissoaform gastropods from the Antarctic and sub-Antarctic: the Eatoniellidae, Rissoidae, Barleeidae, Cingulopsidae, Orbitestellidae and Rissoellidae (Mollusca: Gastropoda) of Signy Island, South Orkney Islands, with a review of the Antarctic and sub-Antarctic (excluding southern South America and the New Zealand sub-Antarctic islands) species. British Antarctic Survey, Scientific Reports 108: 1-96 Rissoidae Gastropods described in 1885