Ridged Cowry, Cyphoma emarginatum

Ridged Cowry, Cyphoma emarginatum. Underwater photographs of actively feeding animals taken in Zihuatanejo Bay, Guerrero, January 2019. Photographs courtesy of Ron Woheau, Zihuatanejo.

Note: the photographs above are of Ridged Cowrys actively feeding in their native environment. I have asked Ron, my collector extraordinaire, to be on the lookout for an abandoned shell. When available I will post additional photo graphs of same.

The Ridged Cowry, Cyphoma emarginatum (G.B. Sowerby I, 1830), is a gastropod mollusk that is a  member of the Ovulidae Family of False Cowries. They are also known at the Emarginate Cyphoma. The shell has a prominent transverse dorsal ridge and a thick callus on the outer lip. The shell is beige to off-white in color. They have a very large retractable mantle that can cover the entire shell while they are feeding. The mantle is black with white proximal transverse striations that abruptly transition to yellow-orange at the margins. They are randomly covered with back, found centrally, and white, found on the margins, papillae. The Ridged Cowry reach a maximum length of 3.0 cm (1.2 inches).

The Ridged Cowry are found in the subtidal zone at depths between 3 m (10 feet) and 18 m (60 feet). They range from the Sea of Cortez south to Ecuador.

Synonyms include Cyphoma emarginata, Cyphoma marginata, and Ovulum emarginatum.