Cassinae
Encyclopedia
Cassidae is a taxonomic family
of medium-sized, large and sometimes very large sea snail
s commonly called helmet snails or bonnet snails. These are marine
gastropod mollusks in the superfamily Tonnoidea
and the clade Littorinimorpha
.
There are about 60 species in the family Cassidae. An example of a member of the family Cassidae is Cypraecassis rufa
.
to depths of 100m, buried in the sand during the day and becoming active at night.
. The coiling may be trochospiral or convolute
. The shell of many species have a great variability. This has led to many wrong indentifications, resulting in many synonyms.
Many species have a large and solid shield over the parietal body or beside the thick, plicated columella
. Many species show blunt knobs and thickened axial ridges, known as varices
. The thin, horny operculum
is oval in shape and covers a long aperture
. The siphonal canal
is straight or slightly curved. The outer lip is somewhat thicker at its margin and toothed on the inside.
s), starting by gripping them using the foot. The snail then makes a hole in the urchin through the combined action of a secretion which is rich in sulfuric acid
and by rasping with their radula
. The acid secretion is provided by two large proboscis
glands.
Bouchet & Rocroi still listed Cassidae as Cassinae Latreille, 1825 , a subfamily of Tonnidae
Suter, 1913 (1825), following in this Riedel (1995) . In his "Revision of the deep-water Cassidae" however , Beu raised in 2008 Cassinae to the rank of family. .
Genus Microsconsia
Beu, 2008
Genus Oocorys
P. Fischer, 1883
Genus Phalium
Link, 1807 - bonnet shells
(Linnaeus, 1758)
Phalium coronadoi (Crosse, 1867)
Phalium fimbria (Gmelin, 1791)
Phalium glaucum
(Linnaeus, 1758)
Genus Sconsia
Gray, 1847
Genus Semicassis
Mörch, 1852
Genera brought into synonymy :
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
of medium-sized, large and sometimes very large sea snail
Snail
Snail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...
s commonly called helmet snails or bonnet snails. These are marine
Marine (ocean)
Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...
gastropod mollusks in the superfamily Tonnoidea
Tonnoidea
Tonnoidea is a superfamily of sea snails, marine gastropod molluscs in the clade Littorinimorpha.-Families:Families within the superfamily Tonnoidea include:*Family Tonnidae*Family Bursidae*Family Laubierinidae*Family Personidae*Family Pisanianuridae...
and the clade Littorinimorpha
Littorinimorpha
Littorinimorpha is a large clade of gastropods within Hypsogastropoda consisting primarily of marine species, but also aquatic and terrestrial species as well....
.
There are about 60 species in the family Cassidae. An example of a member of the family Cassidae is Cypraecassis rufa
Cypraecassis rufa
Cypraecassis rufa is a species of large sea snail, a marine gastropod mollusk in the family Cassidae. It is commonly known as the bullmouth or red helmet shell, and also as the cameo shell.-Distribution:...
.
Distribution
Species of this family occur in tropical and temperate seas from the intertidal zoneIntertidal zone
The intertidal zone is the area that is above water at low tide and under water at high tide . This area can include many different types of habitats, with many types of animals like starfish, sea urchins, and some species of coral...
to depths of 100m, buried in the sand during the day and becoming active at night.
Shell description
Members of this family are shaped rather like bonnets or helmets, as their common name suggests. The shells are large, thick, subglobular with dextrally coiled, sometimes varicose, whorls and a short spireSpire (mollusc)
A spire is a descriptive term for part of the coiled shell of mollusks. The word is a convenient aid in describing shells, but it does not refer to a very precise part of shell anatomy: the spire consists of all of the whorls except for the body whorl...
. The coiling may be trochospiral or convolute
Convolute
Convolute may also refer to:* Convolution ** Circular convolution** Convolution reverb** Convolution sampling** Convolution theorem*** Titchmarsh convolution theorem** Dirichlet convolution** Infimal convolute...
. The shell of many species have a great variability. This has led to many wrong indentifications, resulting in many synonyms.
Many species have a large and solid shield over the parietal body or beside the thick, plicated columella
Columella
Lucius Junius Moderatus Columella is the most important writer on agriculture of the Roman empire. Little is known of his life. He was probably born in Gades , possibly of Roman parents. After a career in the army , he took up farming...
. Many species show blunt knobs and thickened axial ridges, known as varices
Varix (mollusc)
A varix is an anatomical feature of the shell of certain sea snails, marine gastropod molluscs.It is a thickened axial ridge in the shell of some families of gastropods. A varix is located at intervals around the whorl, and is formed by considerable thickening of the outer lip at a resting stage...
. The thin, horny operculum
Operculum (gastropod)
The operculum, meaning little lid, is a corneous or calcareous anatomical structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...
is oval in shape and covers a long aperture
Aperture (mollusc)
The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where part of the body of the animal emerges for locomotion, feeding, etc....
. The siphonal canal
Siphonal canal
Some sea marine gastropods have a soft tubular anterior extension of the mantle called a siphon through which water is drawn into the mantle cavity and over the gill and which serves as a chemoreceptor to locate food. In many carnivorous snails, where the siphon is particularly long, the structure...
is straight or slightly curved. The outer lip is somewhat thicker at its margin and toothed on the inside.
Anatomy
These snails have a large mantle and a large, muscular foot. Their large head has an extensible snout. The eyes are at the base of the single pair of tentacles.Feeding habits
Helmet bonnets prey on echinoderms (especially sea urchinSea urchin
Sea urchins or urchins are small, spiny, globular animals which, with their close kin, such as sand dollars, constitute the class Echinoidea of the echinoderm phylum. They inhabit all oceans. Their shell, or "test", is round and spiny, typically from across. Common colors include black and dull...
s), starting by gripping them using the foot. The snail then makes a hole in the urchin through the combined action of a secretion which is rich in sulfuric acid
Sulfuric acid
Sulfuric acid is a strong mineral acid with the molecular formula . Its historical name is oil of vitriol. Pure sulfuric acid is a highly corrosive, colorless, viscous liquid. The salts of sulfuric acid are called sulfates...
and by rasping with their radula
Radula
The radula is an anatomical structure that is used by molluscs for feeding, sometimes compared rather inaccurately to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters the esophagus...
. The acid secretion is provided by two large proboscis
Proboscis
A proboscis is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In simpler terms, a proboscis is the straw-like mouth found in several varieties of species.-Etymology:...
glands.
Taxonomy
In their taxonomy of the Gastropoda of 2005Taxonomy of the Gastropoda (Bouchet & Rocroi, 2005)
The taxonomy of the Gastropoda as it was revised by Philippe Bouchet and Jean-Pierre Rocroi is currently the most up-to-date overall system for classifying gastropod mollusks...
Bouchet & Rocroi still listed Cassidae as Cassinae Latreille, 1825 , a subfamily of Tonnidae
Tonnidae
Tonnidae is a family of medium-sized to very large sea snails, known as the tun shells. These are marine gastropod molluscs in the clade Sorbeoconcha and the clade Littorinimorpha.- Taxonomy :...
Suter, 1913 (1825), following in this Riedel (1995) . In his "Revision of the deep-water Cassidae" however , Beu raised in 2008 Cassinae to the rank of family. .
Genera
Genera within the family include:- Genus CasmariaCasmariaCasmaria, common name the helmet shells, is a genus of large sea snails, marine gastropod mollusks in the family Cassidae, the helmet shells and their allies...
H. Adams and A. Adams, 1853 - Genus Cassidea Bruguière, 1789
- Genus Cassis ScopoliGiovanni Antonio ScopoliGiovanni Antonio Scopoli was an Italian physician and naturalist.-Biography:...
, 1777 - Genus CypraecassisCypraecassisCypraecassis is a genus of medium-sized to large sea snails, marine gastropod mollusks in the family Cassidae.-Species:Species within the genus Cypraecassis include:* Cypraecassis coarctica * Cypraecassis rufa...
Stutchbury, 1837- Cypraecassis rufaCypraecassis rufaCypraecassis rufa is a species of large sea snail, a marine gastropod mollusk in the family Cassidae. It is commonly known as the bullmouth or red helmet shell, and also as the cameo shell.-Distribution:...
(Linnaeus, 1758) - Cypraecassis testiculusCypraecassis testiculusCypraecassis testiculus, common name the reticulated cowry helmet, is a species of large sea snail, a marine gastropod mollusk in the family Cassidae, the helmet snails and bonnet snails....
(Linnaeus, 1758)
- Cypraecassis rufa
- Genus Dalium Dall, 1889
- Genus EchinophoriaEchinophoriaEchinophoria is a genus of large sea snails, marine gastropod mollusks in the family Cassidae, the helmet snails and bonnet snails.-Species:Species within the genus Echinophoria include:* Echinophoria bituberculosa* Echinophoria carnosa...
- Genus EucorysEucorysEucorys is a genus of large sea snails, marine gastropod mollusks in the family Cassidae, the helmet snails and bonnet snails.-Species:Species within the genus Eucorys include:* Eucorys barbouri...
Beu, 2008 - Genus GaleodeaGaleodeaGaleodea is a genus of large sea snails, marine gastropod mollusks in the family Cassidae. -Species:Species within the genus Galeodea include:* Galeodea alcocki * Galeodea bituminata Galeodea is a genus of large sea snails, marine gastropod mollusks in the family Cassidae. -Species:Species within...
Link, 1807 - Galeodea triganceaeGaleodea triganceaeGaleodea triganceae is a species of large sea snail, a marine gastropod mollusc in the family Cassidae, the helmet snails.-Shell description:The maximum shell height is 48 mm, and maximum width 31 mm.-Distribution:...
DellRichard DellDr Richard Kenneth Dell was a New Zealand malacologist. He was born in Auckland. As a young boy, he took an interest in shells, collecting them from the shores of Waitemata Harbour. He even managed to start a "museum" in his backyard...
, 1953
Microsconsia
Microsconsia is a genus of medium-sized sea snails, marinegastropod mollusks in the family Cassidae, the helmet snails and bonnet snails.-Species:Species within the genus Microsconsia include:* Microsconsia limpusi Beu, 2008...
Beu, 2008
Oocorys
Oocorys is a genus of large, deepwater sea snails, marine gastropod mollusk in the family Cassidae, the helmet snails and bonnet snails.-Species:Species within the genus Oocorys include:* Oocorys barbouri* Oocorys bartschi...
P. Fischer, 1883
- Oocorys abyssorum (Verrill and Smith, 1884)
- Oocorys barbouriOocorys barbouriEucorys barbouri is a species of large sea snail, a marine gastropod mollusk in the family Cassidae, the helmet snails and bonnet snails....
Clench and Aguayo, 1939 - Oocorys bartschiOocorys bartschiEucorys bartschi is a species of large sea snail, a marine gastropod mollusk in the family Cassidae, the helmet snails and bonnet snails....
Rehder, 1943 - Oocorys caribbaea Clench and Aguayo, 1939
- Oocorys lussii Bozzetti, 1990
- Oocorys sulcataOocorys sulcataOocorys sulcata is a species of large sea snail, a marine gastropod mollusk in the family Cassidae, the helmet snails and bonnet snails....
P. Fischer, 1883 - Oocorys verrillii (Dall, 1889)
Phalium
Phalium, common name the bonnet shells, is a genus of large sea snails, marine gastropod mollusks in the family Cassidae, the helmet shells, bonnet shells and their allies.- Species:...
Link, 1807 - bonnet shells
Phalium areola
Phalium areola , common name : the Checkerboard Bonnet, is a species of sea snail, a marine gastropod mollusc in the subfamily Cassinae, within the family Cassidae the helmet and bonnet shells. It is also known as the checkerboard bonnet shell...
(Linnaeus, 1758)
Phalium glaucum
Phalium glaucum, common name the grey bonnet, is a species of large sea snail, a marine gastropod mollusk in the family Cassidae, the helmet snails and bonnet snails....
(Linnaeus, 1758)
Sconsia
Sconsia is a genus of large sea snails, marine gastropod mollusks in the family Cassidae, the helmet snails and bonnet snails.-References:*...
Gray, 1847
- Sconsia nephele F. M. Bayer, 1971
- Sconsia striataSconsia striataSconsia grayi is a species of large sea snail, a marine gastropod mollusk in the family Cassidae, the helmet snails and bonnet snails....
(Lamarck, 1816)
Semicassis
Semicassis is a genus of medium-sized predatory sea snails, marine gastropod molluscs in the subfamily Cassinae within the family Cassidae, the helmet snails and bonnet snails.-Species:...
Mörch, 1852
- Semicassis bisulcata (Schubert & Wagner, 1829)
- Semicassis bulla Habe, 1961
- Semicassis bulla fernandesi (Kilburn, 1975)
- Semicassis craticulata (Euthyme, 1885)
- Semicassis faurotis (Jousseaume, 1888)
- Semicassis granulata (Born, 1778) - synonym: Phalium granulata (Born, 1778)
- Semicassis labiataSemicassis labiataSemicassis labiata is a species of large predatory sea snail, a marine gastropod mollusc. This species is in the subfamily Cassinae, the "helmet shells" and "bonnet shells", which feed on sea urchins.- Subspecies :...
(Perry, 1811) - Semicassis labiata zeylanica (Lamarck, 1822)
- Semicassis pyrumSemicassis pyrumSemicassis pyrum , common name the "pear bonnet" or "common helmet", is a species of large sea snail, a marine gastropod mollusc in the family Cassidae, the tun shells and their allies.-References:...
(Lamarck, 1822) - Semicassis royanaSemicassis royanaSemicassis royana is a species of medium-sized predatory sea snail, a marine gastropod mollusc in the family Cassidae, the helmet shells and their allies.-References:* Powell A. W. B., William Collins Publishers Ltd, Auckland 1979 ISBN 0-00-216906-1...
(Iredale, 1914) - Semicassis sophia (Brazier, 1872)
- Semicassis thomsoniSemicassis thomsoniSemicassis thomsoni is a species of large predatory sea snail, a marine gastropod mollusc in the family Cassidae, the helmet shells and their allies....
(Brazier, 1875) - Semicassis undulataSemicassis undulataSemicassis undulata is a medium-sized species of sea snail, a marine gastropod mollusc in the subfamily Cassinae.This is a Mediterranean species. It has sometimes been confused with the rather similar Western Atlantic species, Semicassis granulata....
(Gmelin, 1791)
Genera brought into synonymy :
- Bathygalea Woodring & Olsson, 1957 : synonym of Echinophoria Sacco, 1890
- Benthodolium Verrill & Smith [in Verrill], 1884 : synonym of Oocorys P. Fischer, 1884
- Cassidaria Lamarck, 1816 : synonym of Galeodea Link, 1807
- Echinora Schumacher, 1817 : synonym of Galeodea Link, 1807
- Galeoocorys Kuroda & Habe, 1957 : synonym of Galeodea Link, 1807
- Hadroocorys Quinn, 1980 : synonym of Oocorys P. Fischer, 1884
- Morio Montfort, 1810 : synonym of Galeodea Link, 1807
- Trachydolium Howe, 1926 † : synonym of Echinophoria Sacco, 1890
Human uses
Some helmet shells are carved into cameos, starting in Italy in 1820.- The king helmet Cassis tuberosaCassis tuberosaCassis tuberosa, common name the king helmet, is a species of very large sea snail with a solid heavy shell, a marine gastropod mollusc in the family Cassidae, the helmet shells and their allies.- Distribution :...
was the first species to be made into cameos. - The black helmet Cassis madagascariensisCassis madagascariensisCassis madagascariensis is a species of very large sea snail, a marine gastropod mollusc in the family Cassidae, the helmet shells and bonnet shells.-Distribution:This species occurs in the tropical Western Atlantic...
, also known as 'Cassis cameo', has a dark brown or a claret-coloured shell layer under a yellowish outer layer. This gives it an onyxOnyxOnyx is a banded variety of chalcedony. The colors of its bands range from white to almost every color . Commonly, specimens of onyx contain bands of black and/or white.-Etymology:...
appearance and makes it one of the most useful shells for cameos. - The red helmet Cypraecassis rufaCypraecassis rufaCypraecassis rufa is a species of large sea snail, a marine gastropod mollusk in the family Cassidae. It is commonly known as the bullmouth or red helmet shell, and also as the cameo shell.-Distribution:...
gives a sardonyxOnyxOnyx is a banded variety of chalcedony. The colors of its bands range from white to almost every color . Commonly, specimens of onyx contain bands of black and/or white.-Etymology:...
-like appearance because it has sardSARDis a Japanese tuning company and racing team from Toyota, Aichi, mainly competing in the Super GT series and specialising in Toyota tuning parts.-History:...
coloured bands under its pale outer coating. - The horned helmet Cassis cornutaCassis cornutaCassis cornuta is a species of very large sea snail, a marine gastropod mollusc in the family Cassidae, the helmet shells and their allies.-Distribution:...
produces a white figure on an orange background. Also used as a trumpet by the native Filipinos.
External links
- http://www.biolib.cz/en/taxon/id402143/ accessed 8 January 2010
- Checklist of Mollusca
- ITIS
- Steyn, D.G. & Lussi, M. 2005. Offshore Shells of Southern Africa ISBN 0-620-33607-2
- http://www.gastropods.com/Taxon_pages/Family_CASSIDAE.shtml#CASSIDAECASSINAE
- http://www.taxonomy.nl/Main/Classification/987895.htm