Chestnut Cowry Shell, Neobernaya spadicea

Chestnut Cowry Shell, Neobernaya spadicea. Size: 5.4 cm (2.1 inches) x 3.2 cm (1.3 inches). Shell collected off the beach in San Diego, California, May 1992. Collection, photograph and identification courtesy of Bob Hillis, Ivins, Utah.

Chestnut Cowry, Neobernaya spadicea.  Underwater photograph taken in coastal waters of  San Diego, California, March 2014. Photograph courtesy of Bob Hillis, Ivins, Utah.

Phylogeny: The Chestnut Cowry, Neobernaya spadicea (Swainson, 1823), is a gastropod mollusk that is a member of the Cypraeidae Family of Cowries. The genus Neobernaya is one of fifty-five genera in this family, and this is the only species in this genus. The species name, “spadicea” is Latin for “the color of fresh dates” in reference to the chestnut coloration. In Mexico this species is known as Ciprea Castaña.

Description: The Chestnut Cowry shell is egg-shaped, glossy, and has a toothed aperture that runs the entire length of the shell. The dorsal surface of the shell is marked by a large irregular patch, chestnut brown in color, surrounded by a dark brown band. The sides and base of the shell are bluish white in color. Individuals that are completely white are occasionally found. The mantle of the living animal is orangish brown, with black spots. The Chestnut Cowry  reaches a maximum of 6.5 cm (2.6 inches) in length and 3.9 cm (1.5 inches) in height.

Habitat and Distribution: Chestnut Cowries are found on rocky ledges and on sheltered rock surfaces. They live subtidally,  to depths up to 50 m (164 feet). They are a temperate Eastern Pacific species. In Mexican waters they are found along the Pacific Coast of the Baja Peninsula from Cedros Island, Baja California, north to the northern border.

Ecology and Behavior: Chestnut Cowries are both predators and scavengers. They prey on sponges, ascidians, anemones, tunicates, and snail eggs, and scavenge carrion. In turn, they are prey for octopuses, rockfish and sea stars. They are gonochoric and reproduce sexually,  with internal fertilization.  The eggs are laid in pointed capsules. The female might lay a hundred capsules, which may each contain 800 eggs. The female protects the eggs until they hatch, which takes about three weeks. Mating occurs in mid-summer. 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: Cypraea (Luponia) spadicea, Cypraea fernandoensis, Cypraea spadicea, and Zonaria spadicea.