, almost 150 freshwater snails are known from Lake Baikal, including 117 endemic species from the subfamilies Baicaliinae (part of the Amnicolidae) and Benedictiinae (part of the Lithoglyphidae), and the families Planorbidae and Valvatidae. All endemics have been recorded between , but the majority mainly live at shallower depths. About 30 freshwater snail species can be seen deeper than , which represents the approximate limit of the sunlight zone, but only 10 are truly deepwater species. In general, Baikal snails are thin-shelled and small. Two of the most common species are "Benedictia baicalensis" and "Megalovalvata baicalensis". Bivalve diversity is lower with more than 30 species; about half of these, all in the families Euglesidae, Pisidiidae, and Sphaeriidae, are endemic (the only other family in the lake is the Unionidae with a single nonendemic species). The endemic bivalves are mainly found in shallows, with few species from deep water.