Bithynia tentaculata

Mean snout snail ( Bithynia tentaculata )

The common muzzle snail ( Bithynia tentaculata ) is a freshwater snail from the family of Bithynias ( Bithyniidae ) that is made to the order of Caenogastropoda. It is widespread in Europe.

Features

The housing is hochkonisch and has 5.5 turns which increase relatively quickly. They are moderately rounded and offset from each other by a distinct suture. The housing is high up to 11 mm and has a max. Thickness or width of 8 mm. The navel is usually not visible. The estuary is approximately oval but pointed at the upper end. The operculum fits exactly in the mouth and is constructed concentrically around a core. The body is dark with yellow speckles

Way of life

The animals are usually 12 to 27 months old. Probably about is a small part of the population another winter and will slightly larger than the rest of the population ( Bithynia tentaculata f producta ). After mating, the female lays 20-40 eggs on stones or any other hard surface, arranged in spawning cords of three eggs in a transverse row. The young hatch, depending on the water temperature after 14 to 20 days. The development of the eggs takes place at temperatures 13-26 ° C. The animals live in stagnant or weakly flowing waters. They feed as grazers and Detritusfiltrierer. Mostly this involves the filtering of life.

Dissemination

The species is widespread throughout Europe with the exception of northern Scandinavia and Greece. In the east, the range extends to western Siberia. In many parts of central Europe the congregation nose screw is one of the most common freshwater snails. She was abducted in the 1870s in the Great Lakes and is now also available in many parts of North America.

System

There are several forms of distinction, but their status is unclear.

• Bithynia tentaculata f codia ( Habitat: Alpine foothills lakes)
• Bithynia tentaculata f gigas ( Occurrence: Denmark and Sweden)
• Bithynia tentaculata f excavata ( Occurrence: United Kingdom, Denmark and Sweden)
• Bithynia tentaculata f bottnica ( Occurrence: Sweden)
• Bithynia tentaculata f producta ( Occurrence: in the range of the species )