''Crassispira incrassata'' is a species of predatory

sea snail Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...

in the family

Pseudomelatomidae Pseudomelatomidae is a family of predatory sea snails, marine gastropods included in the superfamily Conoidea (previously Conacea) and part of the Neogastropoda ( Bouchet & Rocroi, 2005). In 1995 Kantor elevated the subfamily Pseudomelatomina ...

. This species is endemic to the Sea of Cortez, ranging from Western Mexico to Ecuador in

intertidal zone The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of habitats with various species o ...

s. First described in 1834 by George Brettingham Sowerby I, ''C. incrassata'' was reclassified by

William John Swainson William John Swainson FLS, FRS (8 October 1789 – 6 December 1855), was an English ornithologist, malacologist, conchologist, entomologist and artist. Life Swainson was born in Dover Place, St Mary Newington, London, the eldest son of ...

as the holotype specimen for the ''

Crassispira ''Crassispira'' is a genus of small predatory sea snails with narrow, high-spired shells, marine gastropod mollusks in the family Pseudomelatomidae.MolluscaBase (2018). Crassispira Swainson, 1840. Accessed through: World Register of Marine Spec ...

'' genus, but its current taxonomic rank is unclear. The shell has a dark colored, coiled pattern covered in black

periostracum The periostracum ( ) is a thin, organic coating (or "skin") that is the outermost layer of the shell of many shelled animals, including molluscs and brachiopods. Among molluscs, it is primarily seen in snails and clams, i.e. in gastropods and ...

Taxonomy

''Crassispira incrassata'' is a species of sea snail in the family

. It was first described in 1834 by British

conchologist Conchology () is the study of mollusc shells. Conchology is one aspect of malacology, the study of molluscs; however, malacology is the study of molluscs as whole organisms, whereas conchology is confined to the study of their shells. It includ ...

George Brettingham Sowerby I as ''Pleurotoma incrassata'' in his report to the '' Zoological Society of London.'' In 1839,

Louis Charles Kiener Louis Charles Kiener (31 July 1799 – 24 July 1881) was a French malacologist born in Paris. He was the author of the 12-volume ''Spécies général et iconographie des coquilles vivantes comprenant la collection du Muséum d'histoire naturelle ...

described the species as ''Pleurotoma bottae''. The species was later reclassified as ''Crassispira incrassata'' following

's establishment of the ''Crassispira'' genus, for which the holotype specimen of ''Pleurotoma bottae'' was used as the

type Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * Ty ...

species. In 1958, James Hamilton McLean and

Myra Keen Angeline Myra Keen (1905–1986) was an American malacologist and invertebrate paleontologist. She was an expert on the evolution of marine mollusks. With a PhD in psychology. Keen went from being a volunteer, identifying shells at Stanford, and ...

proposed that ''C. incrassata'' represented a southern variation of ''C. bottae,'' but this classification has not been widely adopted.

Description

''Crassispira incrassata'' is a

turrid Turrid, plural turrids, is a common name for a very large group of predatory sea snails, marine gastropod mollusks which until recently were all classified in the family Turridae. However, recently the family was discovered to be polyphyletic ...

(predatory snail) with a mean weight of . The species reproduces sexually and engages in mucus mediated gliding for locomotion.

Shell

''C. incrassata'' has a dextrally coiled shell with a grooved, dark colored shell that hosts a lighter colored interior. The length of the shell ranges between and , and the shell's diameter is . The dark brown shell is coated in a black colored periostracum. The shell is thickest at its base and tapers off to a pyramidal point. The

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). Whorls in nature File:Photograph and axial plane floral ...

s have an incomplete keel along the suture and the keel is ribbed longitudinally. These ribs are grained and are crossed with raised lines. The outer lip is thickened near the edge. The sinus is broad and the

siphonal canal The siphonal canal is an anatomical feature of the shells of certain groups of sea snails within the clade Neogastropoda. Some sea marine gastropods have a soft tubular anterior extension of the mantle called a siphon through which water is ...

is short.iarchive:conchologiaiconi01reev, Conchologia iconica, or, Illustrations of the shells of molluscous animals; Reeve, Lovell, Brooks, Vincent, Reeve, Frederic, Sowerby, G. B.I (George Brettingham), Taylor, John Edward, Reeve Benham & Reeve, Savill, Edwards and Co., Spottiswoode & Co. Vincent Brooks, Day & Son, ; vol.1, p 312 (1843) ''C. incrassatas shell differs from ''Crassispira bottae'' in that it is slightly larger, has a shorter Aperture (mollusc), aperture, and the spine tapers off sooner.

Digestive Tract

The rhynchodeum sphincter is large, posteriorly located, and contiguous with the proboscis wall. The proboscis retractor muscles are large and connected to the rhynchodeum. The proboscis is half the length of the rhychodeum and is coiled inside it. The buccal tube has two anterior sphincters and a sac-like structure. There is an epithelial pad but no intermediate sphincter. Both the buccal tube wall and proboscis wall are thick, but the buccal lips and buccal sac are thin and small. The

buccal mass The digestive system of gastropods has evolved to suit almost every kind of diet and feeding behavior. Gastropods (snails and slugs) as the largest taxonomic class of the mollusca are very diverse: the group includes carnivores, herbivores, scaven ...

is thickly walled and very large relative to other species of snail. The oesophagus runs between the buccal mass and nerve ring. The salivary glands and circular muscle are also very large relative to the snail's size. The

venom gland Venom glands are a wide variety of salivary glands in insects and reptiles modified to produce venom and store it without harm to the organism itself. Details In reptiles the glands are characterized by their ability to synthesize venom, store ve ...

is ciliated before opening up into the buccal cavity behind the oesophagus. The odontophore is medium-sized and made of a single layer of cells that forms a pair of unfused

cartilage Cartilage is a resilient and smooth type of connective tissue. In tetrapods, it covers and protects the ends of long bones at the joints as articular cartilage, and is a structural component of many body parts including the rib cage, the neck an ...

. The

radula The radula (, ; plural radulae or radulas) is an anatomical structure used by molluscs 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 ...

consists of wishbone-shaped teeth; the marginal tooth measuring at 180 μm (0.007 in) in length.TAYLOR, JOHN D. "Foregut anatomy and relationships of the Crassispirinae (Gastropoda, Conoidea)." (1997).

Distribution and ecology

''C. incrassata'' is endemic to the Sea of Cortez, and commonly found from Western Mexico to Ecuador. ''C. incrassata'' is found in intertidal zones and can extend as deep as . The double-crested cormorant predates on this species of snail.

References

External links

* * {{DEFAULTSORT:Crassispira Incrassata incrassata Gastropods described in 1834