Gyraulus crista

Gyraulus crista, commonly called the Nautilus ramshorn, is a minute species of freshwater snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails.

Subspecies

Subspecies include:

Distribution

The distribution of this species is Holarctic, and includes:

Shell description

The minute shell is nearly planispiral in its coiling, but the spire is actually considerably sunken rather than raised (which is usually the case with gastropods).

The shell has regular transverse ridges which form points extending beyond the main curve of the periphery of the shell.

The shell color is a translucent yellowy-brown. The maximum shell dimension is about 3 mm.

Ecology

This snail lives on water plants in freshwater.

This minute species, although technically a pulmonate gastropod, does not use air for respiration but instead absorbs oxygen through its mantle cavity which is full of water.