Valvata cristata

Valvata cristata is a species of minute freshwater snail with an operculum, an aquatic gastropod mollusk or micromollusk in the family Valvatidae, the valve snails.

Distribution

 * Czech Republic - Bohemia and Moravia
 * Slovakia
 * Poland
 * Germany - (Arten der Vorwarnliste)
 * Netherlands
 * the British Isles: Great Britain and Ireland
 * Hungary
 * Kaliningrad Oblast, Russia
 * and other areas

Shell description
The shell of this exceeding small (2–4 mm) Valvata species is very flat in its coiling, and therefore it somewhat resembles a Planorbis shell. However, the shell is dextral in coiling and has an operculum. The shell is transparent, has 3-3.5 whorls in a circular aperture. The umbilicus is wide and open, more than 1/3 of shell diameter.

Ecology
This species lives in stagnant and slow-moving water.

Myzyk (2002) described life cycle of Valvata cristata.