Contracted Cowry Helmet Shell, Cypraecassis coarctata

Contracted Cowry Helmet Shell, Cypraecassis coarctata, Juvenile. Shell courtesy of the commercial fishermen of the greater Los Cabos area, February 2012. Size: 2.6 cm (1.0 inch) x 1.4 cm (0.6 inches).

Contracted Cowry Helmet, Cypraecassis coarctata, Transitioning Juvenile. Shell courtesy of the commercial fishermen of the greater Los Cabos area, February 2012. Size: 3.8 cm (1.5 inches) x 2.4 cm (0.9 inches).

Contracted Cowry Helmet, Cypraecassis coarctata, Adult. Shell courtesy of the commercial fishermen of the greater Los Cabos area, March 2013. Size: 7.6 cm (3.0 inches) x 4.3 cm (1.7 inches).

Phylogeny: The Contracted Cowry Helmet, Cypraecassis coarctata (G.B. Sowerby, 1825), is a gastropod mollusk that is a member of the Cassidae Family of Helmet Shells. The genus Cypraecassis is one of thirteen genera in this family, and there are six species in this genus. They are also known as the Narrow-mouthed Helmet and in Mexico as Caracol Casco Angosto.

Description: The Contracted Cowry Helmet shell is cylindrical to egg-shaped with a low pointed spire. The exterior of the shell is sculpted with four rows of tubercles running the length of the body whorl. There are also finer lines spiraling down the whorl, between the tubercles. The aperture is wider at the anterior end, contracting toward the spire. The aperture has teeth on both sides. The siphon canal is sharply bent. The exterior of the shell is cream to beige in color, with dark brown to reddish-brown mottling. The aperture is yellowish to orange. Contracted Cowry Helmet shells reach a maximum of 8.9 cm (3.5 inches) in length and 5.0 cm (2.0 inches) in height.

Habitat and Distribution: Contracted Cowry Helmets are found on and within sand substrate, from the intertidal zone to depths up to 30 m (100 feet). They are a subtropical to tropical Eastern Pacific species. In Mexican waters they range from Magdalena Bay, Baja California Sur, to Guatemala. They are found throughout the Gulf of California.

Ecology and Behavior: Contracted Cowry Helmets are predators that feed primarily on echinoderms. They use their foot and mantle to pin prey to the bottom. They, in turn, are prey for crabs, fish, and other mollusks. They are gonochoric and reproduce sexually, through broadcast spawning. There is no mention in the available literature of them engaging in any types of parasitic, commensal, or symbiotic relationships. From a conservation perspective they have not been formally evaluated however they are fairly common with a relatively wide distribution and should be consider to be of Least Concern.

Synonyms: Cassis coarctata and Cypraecassis (Levenia) coarctata.