Sanguine Cantharus Shell, Gemophos sanguinolentus

Sanguine Cantharus Shell, Gemophos sanguinolentus. Shell courtesy of the commerical fishermen of the greater Los Cabos area, Baja California Sur, May 2010. Size: 2.3 cm (0.9 inches) x 1.8 cm (0.7 inches).

The Sanguine Cantharus, Gemophos sanguinolentus (Duclos, 1833), is a gastropod mollusk that is a member of the Pisaniidae Family of False Tritons. They are also known as the Measles-mouth Whelk and in Mexico as cantarus sanguinolento. The shells are stocky and solid and have a large body whorl and consist of five or six whorls with large and oval apertures with notches at the top and bottom with an outer lip that is thick and crenulated (marked with numerous small ridges) and the inner lip is small with raised bumps. They have several strong, wide, rounded rips running the length of the shell with fine, brown, spiral lines travel along the whorls, a moderately large spire and body whorl are moderately large. The exterior of the shell is gray to brown in color; the inner lip of the aperture is red and marked with white and in some shells the red continues along the outer lip; the interior is white. The Sanguine Cantharus Shells reach a maximum of 3.2 cm (1.3 inches) in length and 2.5 cm (1.0 inch) in height.

Sanguine Cantharus are found attached to and often associated with coral reefs in the intertidal zone to depths up to 20 m (65 feet). They range from Todos Santos, Baja California Sur to Peru, including the Cocos, Galapagos and Tres Marias Islands; they are found in southern portions of the Sea of Cortez.

Synonyms include Cantharus sanguinolentus, Pollia Haemastoma, Purpura anguinolenta.