Choanomphalus aorus

Choanomphalus aorus is a species of freshwater air-breathing snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails, or planorbids.

Distribution
This species is found in Lake Baikal, Russia and in Angara River.

Description
The width of the shell is 5 mm; the height of the shell is 3 mm.