Maura Turrid Shell, Crassispira maura

Maura Turrid Shell, Crassispira maura. Shell courtesy of the commercial fishermen of the greater Los Cabos area, Baja California Sur, April 2018. Size: 4.9 cm (1.9 inches) x 1.3 cm (0.5 inches). Identification courtesy of Bob Hillis, Ivins, Utah.

Phylogeny: Maura Turrid Shell, Crassispira maura (G.B. Sowerby I, 1834), is a gastropod mollusk that is a member of the Pseudomelatomidae Family of Turrid Shells. The genus Crassispira is one of sixty genera in this family, and there are two hundred nineteen species in this genus. The name Maura comes from both the Latin and Greek words for dark-skinned, referring to this shell’s dark periostracum. They are also known as the Dark-colored Turrid and in Mexico as Túrido Oscuro.

Description: Maura Turrid Shells are elongate and spindle-shaped. They  consist of ten to eleven whorls and are sculpted with strong, lengthwise, ribs, which produce knobs where they cross the whorls. They also have numerous, fine spiral ridges. The aperture is narrow and runs about one-third the length of the shell. The outside lip of the aperture is thin. The inside edge of the aperture is smooth and straight, until it curves at the top. The exterior of the shell is brown and they are usually covered with a brown periostracum. The interior is white. Maura Turrid Shells reach a maximum of 8.5 cm (3.3 inches) in length and 2.2 cm (0.9 inches) in height.

Habitat and Distribution: Maura Turrid Shells are found in sand, mud, and rubble substrates within the intertidal zone and to depths up to 61 m (200 feet). These shells are a subtropical to tropical Eastern Pacific species that is found in Mexican waters of the Pacific Ocean along the west coast of the mainland south to Guatemala. In the Sea of Cortez they are found form Bahía Bahia de Los Angeles, Baja California south to Cabo San Lucas, Baja California Sur. They have not been documented from the west coast of the Baja Peninsula.

Ecology and Behavior: Maura Turrid Shells are a poorly studied and understood species. There is very limited documentation of their diet, predation, reproduction or ecosystem interactions. Other species Pseudomelatomidae are predators that feed primarily on polychaete worms. They are gonochoric and reproduce sexually. 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 considered to be of Least Concern.

Synonyms: Clathrodrillia inaequistriata, Crassispira perla, Drillia inaequistriata, and Pleurotoma maura.