''Bolinus cornutus'', or horned murex, is a predatory

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of sea snail, a marine gastropod

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Muricidae Muricidae is a large and varied taxonomic family of small to large predatory sea snails, marine gastropod mollusks, commonly known as murex snails or rock snails. With about 1,600 living species, the Muricidae represent almost 10% of the Neoga ...

, the murex or rock snails. This species is common along the west coast of Africa, where it prefers moderately shallow waters. The shell of the snail is distinctively large, spiny, and club-shaped, usually pale brown or tan in colour, with an elongated and straight siphonal canal.

Description

''Bolinus cornutus'' inhabits moderately shallow waters and prefers gravelled or rocky substrate. It is carnivorous and predatory. Although not as widely utilised as other murex species, such as '' Bolinus brandaris'', ''Bolinus cornutus'' is one of the sea snail species from which a rich purple dye, generally referred to as

Tyrian purple Tyrian purple ( grc, πορφύρα ''porphúra''; la, purpura), also known as Phoenician red, Phoenician purple, royal purple, imperial purple, or imperial dye, is a reddish-purple natural dye. The name Tyrian refers to Tyre, Lebanon. It i ...

, can be extracted. The dye is a mucus from the snail's

hypobranchial gland The hypobranchial gland is a glandular structure which is part of the anatomy of many mollusks, including several different families of gastropods, and also many protobranch bivalves. This gland produces mucus as well as biologically active compo ...

, which is secreted for defence and as an aid in predation. ''Bolinus cornutus'' is protected by a large, thick, spiny shell, club-shaped and with a broad body whorl. The maximum length of the shell is approximately 200 millimetres. Its

spire A spire is a tall, slender, pointed structure on top of a roof of a building or tower, especially at the summit of church steeples. A spire may have a square, circular, or polygonal plan, with a roughly conical or pyramidal shape. Spires a ...

is low and the body whorl has six or seven

varices A varix (pl. varices) is an abnormally dilated vessel with a tortuous course. Varices usually occur in the venous system, but may also occur in arterial or lymphatic vessels. Examples of varices include: * Varicose veins, large tortuous veins usua ...

, each varix forming two long, hollow spines. Short spines also spiral off the long, straight siphonal canal of the shell, which is narrowly open along its length. The buff or tan shell colour is interrupted on the body whorl by three darker brown spiral bands, spaced evenly. The majority of the ovate

aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An ...

of the shell is white, with an "apricot" shade on the lip edge, the inductura, and the

parietal callus A parietal callus is a feature of the shell anatomy of some groups of snails, i.e. gastropods. It is a thickened calcareous deposit which may be present on the parietal wall of the aperture of the adult shell. The parietal wall is the margin of ...

. Most of the outer surface of the shell is rough in texture.

Distribution

''Bolinus cornutus'' is found along the Atlantic coast of Africa; it is not an uncommon species.

References

External links

* {{Taxonbar, from=Q1498637 Muricinae Gastropods described in 1758 Taxa named by Carl Linnaeus