Litiopa melanostoma, common name the brown Sargassum shell, is a species of very small sea snail, a marine gastropod mollusk or micromollusk in the family Litiopidae.
This species occurs in the Gulf of Mexico, the Caribbean Sea, the Lesser Antilles, Puerto Rico and off the Azores; in the North Atlantic Ocean, off Newfoundland.
Litiopa melanostoma (Sargassum Snail) has been found to have a maximum recorded shell length of 6 mm.[1]
The minimum recorded depth for this species is 0 m; the maximum recorded depth is 805 m.[1] The snail is known to live on floating beds of Sargassum.