Teasel Murex Shell, Murexsul dipsacus

Teasel Murex Shell, Murexsul dipsacus. Size: 7.6 cm (3.0 inches) x 3.8 cm (1.5 inches) x 3.8 cm (1.5 inches). Shell collected off the beach in the greater Agua Verde area, Baja California Sur, February 2020. Collection and photography courtesy of Barry Mastro, Escondido, California. Identification courtesy of Bob Hillis, Ivins, Utah and should be considered a tentative identification as this shell is relatively unknown and the size of the pictured shell exceeds the known maximum for the Teasel Murex.

The Teasel Murex, Murexsul dipsacus (Broderip, 1833), is a gastropod mollusk that is a member of the Muricidae Family of Rocks. They are named for their resemblance to the head of a Teasel or Thistle Plant. They are solid, fairly globose shells which have six whorls, seven to nine varices and a moderately high spire. Their aperture is circular to slightly oval and the canal is moderately long and open. The axil ribs and spines vary in length from species to species. The exterior of the shells is whitish with varying numbers of brown bands or blotches; the interior is white. Teasel Murex shells reach a maximum of 7.6 cm (3.0 inch) in length and 3.8 cm (1.5 inches) in height, assuming the identification of the shell pictured above is correct.

Teasel Murex are found on cobbles and rocks at depths between 20 m (66 feet) and 37 m (121 feet). Their primary prey are barnacles and bivalves; in turn they are preyed upon by crabs, fish, and sea stars. They range from Magdalena Bay, Baja California Sur south to Guatemala including throughout the Sea of Cortez.

Synonyms include Murex dipsacus, Murex negritus, Murex octonus, Murex peruvianus, Murexiella dipsacus, Muricanthus negritus, Murexiella octonus and Murexiella radicata.