Cryptofissurella

Cryptofissurella is a genus of small, freshwater snails with a gill and an operculum, an internal shell that covers the aperture. They are part of the family Hydrobiidae and are commonly found in slow-moving or stagnant freshwater habitats. The genus was first described by the German malacologist Friedrich August von Quenstedt in 1858.

The shells of Cryptofissurella are typically small, ranging from 1.5 to 3.5 millimeters in height, and have a globose to slightly elongated shape. They are usually brown or reddish-brown in color, with a smooth or slightly sculptured surface. The aperture is rounded and slightly oblique, with a thin, translucent peristome.

Cryptofissurella species are known for their ability to tolerate a wide range of environmental conditions, including low oxygen levels and high levels of pollution. They are often found in habitats that are disturbed or degraded, such as urban streams and polluted ponds.

The genus Cryptofissurella is currently represented by three species: C. crypta, C. fissurella, and C. subfissurella. All three species are found in Europe, with C. crypta and C. fissurella also occurring in North America. The taxonomy of the genus is still under study, and new species may be discovered in the future.

Cryptofissurella snails are an important part of the freshwater ecosystem, serving as a food source for various predators and contributing to the overall biodiversity of their habitats. However, their populations are threatened by habitat loss and degradation, as well as pollution. Conservation efforts are needed to protect these small but important freshwater snails.