Melanopsids are medium-sized freshwater snails, with ovate to elongate conical shells that either have a smooth surface or may be ornamented with often nodulous ribs. The aperture is usually narrow, pointed above and usually with truncated columella. The operculum is corneous and pausispiral, with a basal nucleus. The posterior oviduct is open, the cerebralpedal connectives are short, the osphradium is less than half the etenidial length.
Species in this family are native to southern and eastern Europe, northern Africa, parts of the Middle East, New Zealand, and freshwater streams of some large South Pacific islands.
These snails first appeared in the Late Cretaceous and are closely related to Potamididae. As well as unidirectional evolutionary change from one species to the next over time, the process of hybridization plays a major role in the appearance of new Melanopsidae species.
A total of 36 species assigned to the family Melanopsidae are currently listed in the ICUN Red list, 10 as critically endangered, 6 as endangered, 2 as vulnerable, 1 as near threatened, 8 as least concerned and 6 as data deficient, implying that half the taxa in the family are threatened with extinction as all freshwater species.