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 natu ...

(IUCN) lists 581 critically endangered

mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...

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 A data deficient (DD) species is one which has been categorized by the International Union for Conservation of Nature (IUCN) as offering insufficient information for a proper assessment of conservation status to be made. This does not necessaril ...

'', 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. Ther ...

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

Stylommatophora Stylommatophora is an orderPhilippe Bouchet, Jean-Pierre Rocroi, Bernhard Hausdorf, Andrzej Kaim, Yasunori Kano, Alexander Nützel, Pavel Parkhaev, Michael Schrödl and Ellen E. Strong. 2017. Revised Classification, Nomenclator and Typification ...

Stylommatophora includes the majority of land snails and slugs. There are 233 species and five subspecies in the order Stylommatophora assessed as critically endangered.

Amastrids

Partulids

Achatinellids

Endodontids

Species Subspecies

Charopids

Helicarionids

Orthalicids

Rhytidids

Streptaxids

Lauriids

Helicids

Hygromiids

Enids

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.); Fr� ...

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

Hydrobiids

Cochliopids

Bithyniids

Moitessieriids

*''

Henrigirardia wienini ''Henrigirardia wienini'' is a species of terrestrial gastropod in the family Moitessieriidae endemic to caves near Aniane Aniane (; oc, Aniana) is a commune in the Hérault department in the Occitanie region in southern France. Populati ...

'' (possibly extinct) *''

Spiralix corsica ''Spiralix'' is a genus of very small aquatic snails, operculate gastropod mollusks in the family Moitessieriidae Moitessieriidae is a family of small freshwater snails, aquatic gastropod molluscs in the superfamily Truncatelloidea.Bouchet ...

'' (possibly extinct)

Assimineids

Pomatiopsids

Sorbeoconcha Sorbeoconcha is a taxonomic clade of snails, i.e. gastropods, mainly marine species with gills and opercula, within the clade Caenogastropoda. The taxon Sorbeoconcha was named by Winston Ponder and David R. Lindberg in 1997. Taxonomy 1 ...

Architaenioglossa Architaenioglossa is a taxonomic group of snails which have gills and often an operculum. They are primarily land and freshwater gastropod mollusks within the clade Caenogastropoda. This " informal group" has been shown to be polyphyletic in a s ...

There are 48 species in the order Architaenioglossa assessed as critically endangered.

Cyclophorids

Diplommatinids

Viviparids

Other Architaenioglossa species

Cycloneritimorpha Cycloneritida (nerites and false-limpets) is an order of land snails, freshwater snails, and sea snails.MolluscaBase eds. (2020). MolluscaBase. Cycloneritida. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/ap ...

Hygrophila

Species Subspecies *'' Bulinus tropicus torensis''

Neogastropoda Neogastropoda is an order of sea snails, both freshwater and marine gastropod molluscs. Description The available fossil record of Neogastropoda is relatively complete, and supports a widely accepted evolutionary scenario of an Early Creta ...

Other gastropod species

Bivalvia Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of w ...

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 F ...

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

Margaritiferids

Species Subspecies *''

Margaritifera margaritifera durrovensis The Nore pearl mussel (''Margaritifera durrovensis'') is a critically endangered species of freshwater pearl mussel, an aquatic bivalve mollusc in the family Margaritiferidae. The species is endemic to Ireland and was first identified by R.A. ...

Etheriids

*'' Acostaea rivolii''

Unionids

Species Subspecies

Hyriids

* Glenelg freshwater mussel ''(Hyridella glenelgensis)''

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, ...

Cephalopods A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, an ...

*''

Opisthoteuthis chathamensis ''Opisthoteuthis chathamensis'' is a species of cirrate octopus restricted to demersal habitats surrounding the Chatham Rise in New Zealand. It is commonly known as the roughy umbrella octopus. Distribution, description & threats Specimens hav ...

References

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