Tiger Turret Shell, Caviturritella leucostoma

Tiger Turret Shells, Caviturritella leucostoma. Size: 7.7 cm (3.9 inches) x 1.7 cm (0.7 inches). Shells collected off the beach in the greater Los Cabos area, Baja California Sur, May 2009.

Phylogeny: The Tiger Turret Shell, Caviturritella leucostoma (Valenciennes, 1832), is a gastropod mollusk that is a member of the Turretellidae Family of Turret Shells. The genus Caviturritella is one of twenty-four genera in this family, and there are four species in this genus. They are also known as the White-mouth Screw Shell and in Mexico as Caracol Torre.

Description: Tiger Turret Shells have eighteen to twenty fairly flat whorls giving the shell an angular appearance. There are several fine ridges running along the whorls. The exterior of the shell is light gray, tan or white, or tan with brown or reddish-brown streaks running obliquely down the whorls. Some individuals appear to have a series of dashes running along segments of the whorls. The aperture is white. Tiger Turret Shells reach a maximum of 12.3 cm (4.8 inches) in length and 2.7 cm (1.1 inches) in height.

Habitat and Distribution: Tiger Turrets are found on sand within the intertidal zone, and to depths up to 50 m (165 feet). They are a subtropical to tropical Eastern Pacific species that are found in all Mexican waters of the Pacific Ocean with the exception that they are absent from north of Ensenada, Baja California, along the extreme northwest coast of the Baja Peninsula.

Ecology and Behavior:  Tiger Turrets are suspension feeders, which use mucous strings to capture plankton and suspended organic matter. They are preyed upon by crabs and other gastropods, especially Moon Snails and Murexes. Angle-mouth Screws are gonochoric. Reproduction is sexual, with internal fertilization. Their engagement in any form of commensal, parasitic, or symbiotic relationships has not been formally documented. From a conservation perspective the Tiger Turret has not been formally evaluated. However, they are fairly common with a relatively wide distribution and should be considered to be of Least Concern.

Synonyms: Turritella cumingii, Turritella dura, Turritella leucostoma, and Turritella tigrina.