As of September 2016, the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the stat ...

(IUCN) listed 581

critically endangered An IUCN Red List critically endangered (CR or sometimes CE) species is one that has been categorized by the International Union for Conservation of Nature as facing an extremely high risk of extinction in the wild. As of December 2023, of t ...

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

species, including 117 which are tagged as possibly extinct. Of all evaluated mollusc species, 8.0% 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 Gastropods (), commonly known as slugs and snails, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and from the 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 of ...

Stylommatophora includes the majority of land snails and slugs. There are 233 species and five subspecies in the order Stylommatophora 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 ( limnic 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.

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 ...

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

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/a ...

Hygrophila

Species Subspecies *'' Bulinus tropicus torensis''

Neogastropoda

Other gastropod species

Bivalvia Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of aquatic animal, aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed b ...

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

Unionida Unionida is a monophyletic order (biology), order of freshwater mussels, aquatic animal, 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. (20 ...

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, ...

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

*'' Opisthoteuthis chathamensis''

References

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