As of September 2016, the International Union for Conservation of Nature (IUCN) lists 507 endangered mollusc species. 7.0% of all evaluated mollusc species are listed as endangered. The IUCN also lists nine mollusc subspecies as endangered.
No subpopulations of molluscs have been evaluated by the IUCN.
For a species to be considered endangered by the IUCN it must meet certain quantitative criteria which are designed to classify taxa facing "a very high risk of exintction". An even higher risk is faced by critically endangered species, which meet the quantitative criteria for endangered species. Critically endangered molluscs are listed separately. There are 1088 mollusc species which are endangered or critically endangered.
Additionally 1988 mollusc species (27% of those evaluated) are listed as data deficient, meaning there is insufficient information for a full assessment of conservation status. As these species typically have small distributions and/or populations, they are intrinsically likely to be threatened, according to the IUCN. While the category of data deficient indicates that no assessment of extinction risk has been made for the taxa, the IUCN notes that it may be appropriate to give them "the same degree of attention as threatened taxa, at least until their status can be assessed."
This is a complete list of endangered mollusc species and subspecies evaluated by the IUCN.
There are 448 species and seven subspecies of gastropod assessed as endangered.
Stylommatophora includes the majority of land snails and slugs. There are 187 species and two subspecies in the order Stylommatophora assessed as endangered.
SubspeciesStock Island tree snail (Orthalicus reses reses)
SubspeciesTayloria urguessensis subangulata
There are 147 species and three subspecies in the order Littorinimorpha assessed as endangered.
SubspeciesBellamya unicolor abyssinicus
Maizania hildebrandti thikensis
There are 22 Hygrophila species assessed as endangered.
There are 57 species and two subspecies in the class Bivalvia assessed as endangered.
There are 54 species and two subspecies in the order Unionoida assessed as endangered.
SubspeciesCatspaw (Epioblasma obliquata obliquata)
Rough rabbitsfoot (Quadrula cylindrica strigillata)