As of September 2016, the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of nat ...

(IUCN) lists 581 critically endangered mollusc species, including 117 which are tagged as ''possibly extinct''. 8.0% of all evaluated mollusc species are listed as critically endangered. The IUCN also lists 11 mollusc subspecies as critically endangered. No subpopulations of molluscs have been evaluated by the IUCN. 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 critically endangered mollusc species and subspecies evaluated by the IUCN. Species considered possibly extinct by the IUCN are marked as such.

Gastropods The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. The ...

There are 511 species and six subspecies of gastropod assessed as critically endangered.

Other Stylommatophora species

Littorinimorpha Littorinimorpha is a large order of snails, gastropods, consisting primarily of sea snails (marine species), but also including some freshwater snails ( aquatic species) and land snails ( terrestrial species).Bouchet P. & Rocroi J.-P. (Ed.); Frý ...

There are 181 species in the order Littorinimorpha assessed as critically endangered.

Other gastropod species

Bivalvia Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, biva ...

There are 69 species and five subspecies in the class Bivalvia assessed as critically endangered.

Unionida Unionida is a monophyletic order of freshwater mussels, aquatic bivalve molluscs.Bieler R., Carter J.G. & Coan E.V. (2010). ''Classification of Bivalve families''. pp. 113–133, in: Bouchet P. & Rocroi J.-P. (2010), ''Nomenclator of Bivalve Fa ...

There are 66 species and five subspecies in the order Unionoida assessed as critically endangered.

Venerida Venerida (formerly Veneroida) is an order of mostly saltwater but also some freshwater bivalve molluscs. This order includes many familiar groups such as many clams that are valued for food and a number of freshwater bivalves. Since the 2000s, t ...

Cephalopods

*'' Opisthoteuthis chathamensis''

References

* *Molluscs Critically endangered molluscs {{bots, deny=BG19bot,Yobot