Cassinae

Taxobox
name = Cassinae


image_caption = "Semicassis pyrum"
regnum = Animalia
phylum = Mollusca
classis = Gastropoda
ordo = Littorinimorpha
superfamilia = Tonnoidea
familia = Tonnidae
subfamilia = Cassinae
subfamilia_authority = Latreille, 1825
subdivision_ranks = Genera and species
subdivision = See text.

Cassinae is a taxonomic subfamily of medium-sized, large and sometimes very large sea snails commonly called helmet snails or bonnet snails. These are marine gastropod mollusks of the superfamily Tonnoidea and the clade Littorinimorpha. There are about 60 species in this family.

Distribution

The subfamily Cassinae contains species which occur in tropical and temperate seas.

Habitat

Most species in this family live from the intertidal zone down to about 100 m in depth.

hell description

Members of this subfamily are shaped as their common name suggests, rather like bonnets or helmets. Many species have a large and solid parietal shield.

The subfamily is also renowned for great shell variability within some of the species. This is particularly evident in "Semicassis pyrum" and "Semicassis labiata" where a number of variants have been described, as species, subspecies and forms. Some of these named forms still require investigation to determine their exact relationships.

Life habits

Most helmet shells live buried in the sand by day, coming out at night to feed on echinoderms, especially sea urchins, which they can locate by smell from at least 30 cm away. They immobilise the urchin, crawl onto it with the thick skin of the foot providing protection from the spines, and make a hole in the urchin shell by an acidic secretion and by rasping with the radula, and suck out the soft parts.

Genera and species

* Genus "Casmaria" H. Adams and A. Adams, 1853
** "Casmaria ponderosa perryi" (Iredale, 1912)
* Genus "Galeodea" Link, 1807
** "Galeodea triganceae" Dell, 1953
* Genus "Cassis" Scopoli, 1777
** "Cassis cornuta" Linnaeus, 1758
** "Cassis flammea" (Linnaeus, 1758)
** "Cassis madagascariensis" Lamarck, 1822
** "Cassis tuberosa" (Linnaeus, 1758)
* Genus "Cypraecassis" Stutchbury, 1837
** "Cypraecassis testiculus" (Linnaeus, 1758)
* Genus "Oocorys" P. Fischer, 1883
** "Oocorys abyssorum" (Verrill and Smith, 1884)
** "Oocorys barbouri" Clench and Aguayo, 1939
** "Oocorys bartschi" Rehder, 1943
** "Oocorys caribbaea" Clench and Aguayo, 1939
** "Oocorys sulcata" P. Fischer, 1883
** "Oocorys verrillii" (Dall, 1889)
* Genus "Phalium" Link, 1807
** "Phalium coronadoi" (Crosse, 1867)
** "Phalium granulatum" (Born, 1778)
* Genus "Sconsia" Gray, 1847
** "Sconsia nephele" F. M. Bayer, 1971
** "Sconsia striata" (Lamarck, 1816)
* Genus "Semicassis" Mörch,1852
** "Semicassis granulata granulata" (Born, 1778)
** "Semicassis labiata" (Perry, 1811)
** "Semicassis pyrum" Powell, 1928
** "Semicassis royana" (Iredale, 1914)
** "Semicassis sophia" (Brazier, 1872)
** "Semicassis thomsoni" (Brazier, 1857)

References

* [http://www.mollusca.co.nz/checklist/checklist_frameset.htm Checklist of Mollusca]
* [http://www.itis.gov/servlet/SingleRpt/SingleRpt ITIS]