"The mainstream river snail, also known as the onyx rocksnail, scientific name Leptoxis praerosa, is a species of freshwater snail with a gill and an operculum, an aquatic gastropod mollusk in the family Pleuroceridae. This species is endemic to the United States."@en . . "Mainstream river snail"@en . . . . . "IUCN2.3" . . "VU" . .