Heleobia stagnorum is a species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of small freshwater snail

Freshwater snail

A freshwater snail is one kind of freshwater mollusc, the other kind being freshwater clams and mussels, i.e. freshwater bivalves. Specifically a freshwater snail is a gastropod that lives in a watery non-marine habitat. The majority of freshwater gastropods have a shell, with very few exceptions....

 with a gill

Gill

A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water, afterward excreting carbon dioxide. The gills of some species such as hermit crabs have adapted to allow respiration on land provided they are kept moist...

 and an operculum

Operculum (gastropod)

The operculum, meaning little lid, is a corneous or calcareous anatomical structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...

, an aquatic

Aquatic animal

An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...

 gastropod mollusk in the family Cochliopidae

Cochliopidae

Cochliopidae is a family of small freshwater snails with gills and an operculum, aquatic gastropod mollusks.This family is in the superfamily Rissooidea and in the clade Littorinimorpha ....

.

The exact classification of this species on a generic level is uncertain. Giusti & Pezzoli in 1984 moved it to Heleobia. Previously the species was placed in several different genera: Hydrobia, Semisalsa, Ventrosia, Heleobia and Ecrobia Stimpson, 1865.

Distribution

This species occurs in:

• Great Britain
• The Netherlands
• Germany