Speciosa Rock Shell, Vasula speciosa

Speciosa Rock Shell, Vasula speciosa. Shell collected off the beach at Punta Chivato, Baja California Sur, April 2022. Size: 3.6 cm (1.4 inches) x 3.3 cm (1.3 inches). Collection, photographs and identification courtesy of Colin Campbell, DVM, Punta Chivato, Baja California Sur.

Speciosa Rock Shell, Vasula speciosa. Shell courtesy of the commercial fishermen of the greater Los Cabos area, Baja California Sur, April 2011. Size: 3.7 cm (1.5 inches) x 3.1 cm (1.2 inches).

The Speciosa Rock, Vasula speciosa (Valenciennes, 1832), is a gastropod mollusk that is a member of the Muricidae Family of Rocks. The shells have a diamond shaped profile with broad shoulders that have rows of short spiny ridges or knobs three of which project at the outer lip of the aperture as spines with the lower two being shorter than the upper one, a body whorl that tapers quickly and a low spire. The exterior of the shell is white, with spiral bands of brown squares; the interior is white and many individuals have yellow inside the aperture. The Speciosa Rock Shells reach a maximum of 4.0 cm (1.6 inches) in length and 3.4 cm (1.3 inches) in height.

Speciosa Rock Shells are found clinging to rocks, in the intertidal zone to depths up to 5 m (15 feet). They range from Magdalena Bay, Baja California Sur to Peru, including the Galapagos Islands. They are found throughout the Sea of Cortez.

A synonym is Thais speciosa.