''Abyssochrysos'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of bathyal

sea snail Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...

s, marine

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

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

s in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Abyssochrysidae Abyssochrysidae is a family of sea snails, marine gastropod mollusks in the clade Caenogastropoda (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005). Taxonomy The family Abyssochrysidae was previously placed in the "Zygo ...

Description

The characteristics (shell, radula and anatomy) of the species mark this genus as simple gastropods, unassigned in the clade

Caenogastropoda Caenogastropoda is a taxonomic subclass of molluscs in the class Gastropoda. It is a large diverse group which are mostly sea snails and other marine gastropod mollusks, but also includes some freshwater snails and some land snails. The subcla ...

. Their taenioglossate

radula The radula (; : radulae or radulas) is an anatomical structure used by mollusks for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters ...

(formula: 2+1+1+1+2) is unique among the

Prosobranchia Prosobranchia was a large Taxonomy (biology), taxonomic Class (biology), subclass of sea snails, land snails and freshwater snails. This taxon of gastropods dates back to the 1920s. It has however been proven to be polyphyly, polyphyletic (consis ...

because of the sickle-shaped rachidian tooth and the thick, sinuous, sharply cusped lateral teeth. They have tentacles but lack eyes. The mantle cavity goes deep (about 2½

whorl A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). In nature File:Photograph and axial plane floral diagra ...

s). The long, wide ctenidium is monopectinate. The pallial gonoducts are closed. The large penis-like organ is a right-dorsal mantle process.

Species

Species within the genus ''Abyssochrysos'' include: * '' Abyssochrysos bicinctus'' Bouchet, 1991Bouchet P. (1991). "New records and new species of ''Abyssochrysos'' (Mollusca, Caenogastropoda). ''Journal of Natural History'' 25(2): 305–313. . * † '' Abyssochrysos bituminifer'' (C. W. Cooke, 1919) * '' Abyssochrysos brasilianus'' Bouchet, 1991 * † '' Abyssochrysos costatus'' (C. W. Cooke, 1919) * '' Abyssochrysos eburneus'' Locard, 1897 * '' Abyssochrysos melanioides'' Tomlin, 1927 * '' Abyssochrysos melvilli'' Schepman, 1909 * '' Abyssochrysos xouthos'' Killeen & Oliver, 2000 ;Species brought into synonymy: * ''Abyssochrysos bicinctum'' (Bouchet), 1991: synonym of ''Abyssochrysos bicinctus'' (Bouchet, 1991) * ''Abyssochrysos brasilianum'' (Bouchet), 1991: synonym of ''Abyssochrysos brasilianus'' (Bouchet, 1991) * ''Abyssochrysos eburneum'' (Locard, 1897): synonym of ''Abyssochrysos eburneus'' (Locard, 1897) * † ''Abyssochrysos giganteum'' Kiel, K. A. Campbell, Elder & C. Little, 2008: synonym of † '' Ascheria gigantea'' (Kiel, K. A. Campbell, Elder & C. Little, 2008) (original combination) * ''Abyssochrysos tomlini'' Barnard, 1963: synonym of '' Abyssochrysos melvilli'' (Schepman, 1909)

References

* Bouchet P. (1991). ''New records and new species of Abyssochrysos (Mollusca, Caenogastropoda). Journal of Natural History 25(2): 305–313

External links

Tomlin, J. R. le B. (1927). Reports on the marine Mollusca in the collections of the South African Museum. II. Families Abyssochrysidae, Oocorythidae, Haliotidae, Tonnidae. Annals of the South African Museum 25(1): 77–83.

Houbrick, R. S. (1979). Classification and systematic relationships of the Abyssochrysidae, a relict family of bathyal snails (Prosobranchia; Gastropoda). Smithsonian Contributions to Zoology. 290: 1-21
{{Commons category Abyssochrysidae