Description

 

Muricidae, the largest family among the marine snails, have extremely variable shells. All are active predators and tropical or semi-tropical in habitat. Most have radulas adapted for tearing flesh and capable of drilling. However, for most, chipping away the edges of a clam shell is preferred to boring. In borers, an accessory boring organ secretes a calcium chelating compound that softens a shell during the drilling process, like the naticids. Drilling is then carried out by the radula. The paralytic agent that the most muricids use for killing is a neurotoxic mucus secretion of the hypobranchial gland. Oddly enough, this secretion also turns up in several entirely unrelated gastropod families. The mucus secretion, particularly from the Thaiidinae (see below), has been used also by people of antiquity, to manufacture a remarkably stable purple dye (Monfils, 2001).

 

Abbott & Dance identify six distinct subfamilies of the Muricidae, largely based on detailed features of the radula. Several were formerly considered separate families.  

Muricinae. Immediately recognizable as murex species, the shell is generally club-shaped with a rond aperture and anterior canal. Bizarre varices. or projecting leafs of the shell (laid down by the mantle, as it grows) are common. 

Ocenebrinae. Shell shapes are variable, but the aperture is elongated and the anterior canal is closed off in most adults. Urosalpinx, is a borer that causes much damage to oyster beds (see radula). The hole it drills for inserting its proboscis is generally rough, somewhat uneven and less beveled than the hole made, for example, by a moon snail (naticids).  

Thaiidinae. Shells are generally compact, lack varices, and are sometimes knobby. The Tyrian purple dye imported by the ancient Romans was made from bulk harvests of Thais and Purpura species. Their indigo secretion is neurotoxic to other organisms and probably used offensively. Some thaids also get at a clam's soft tissue by wedging open the clamshell using a strong tooth developed at the outer lip of their own shell. This is a type of feeding behavior similar to that of the Buccinidae family. See for example (Buccinum undatum opening a clam). 

Trophoninae. These murex shells are thin for their size and typically have rather fragile, arched varices. The aperture is also markedly elongated, with a strong anterior canal. Austrotrophon cerrosensis is representative, but many other species are poorly characterized.

Typhininae. Shells are like those of the Muricinae subframily generally except that the tips of varices are tubular, and the latest varix opens into the aperture. Tubular tips on earlier varices are plugged off. 

Rapaninae. The genus Rapana (not to be confused with the genus Rapa, in the Coralliophilidae family), is rather similar to Drupa in the Thaiidinae subfamily, but it lacks a tooth at the bottom of the shell lip for prying open clams. It  has a canal at the rear of the aperture and is also a very sturdy shell.

 

The Muricidae, Coralliophilidae and Columbariidae families comprise the Muricacea superfamily, most of which show similar features for carnivorous feeding.

 

Classification

Class: Gastropoda

Clade: Neogastropoda

Superfamily: Muricoidea

Family: Muricidae

Major Subfamilies & Genera

Subfamily: Muricinae

• Genus: Bolinus
• Genus: Chicoreus
• Genus: Haustellum
• Genus: Hexaplex
• Genus: Homalocantha
• Genus: Marchia
• Genus: Maxwellia
• Genus: Murex
• Genus: Muricanthus
• Genus: Phylonotus
• Genus: Pterynotus
• Genus: Purpurellus
• Genus: Siratus

Subfamily: Ocenebrinae

• Genus: Ceratostoma
• Genus: Favartia
• Genus: Muricopsis
• Genus: Ocenebra
• Genus: Pteropurura
• Genus: Urosalpinx
• Genus: Vitularia

SubFamily: Rapaninae

• Genus: Chorus
• Genus: Forerria
• Genus: Rapana

SubFamily: Thaidinae

• Genus: Drupa
• Genus: Nucella
• Genus: Purpura
• Genus: Thais

Subfamily: Trophoninae

• Genus: Acanthotrophon
• Genus: Austrotrophon
• Genus: Trophon
• Genus: Trophonopsis 

Subfamily: Typhininae

• Genus: Typhinellus
• Genus: Typhis

Austrotrophon cerrosensis
subspecies catalinensis
(Oldroyd, 1927)
Catalina Trophon,
(a rare shell)

Hexaplex fulvescens (Sowerby, 1834)
Giant Eastern Murex

Purpura persica (Linn,, 1758)
Persian Persica

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