West Indian Chank Shell, Turbinella angulata

West Indian Chank Shell, Turbinella angulata. Collected offshore Cancun, Yucatán, May, 1990. Length 25 cm (10 inches) Width 13 cm (5.1 inches). Collection, Photograph, and identification by Bob Hillis, Ivins Utah.

Phylogeny: The West Indian Chank Shell, Turbinella angulata (Lightfoot, 1786) is a gastropod and a member of the Turbinellidae Family of Chank Shells. The Genus Turbinella is one of three genera in this family, and there are eight species in this genus. They are also known as the Lamp Shell and in Mexico as Caracol Tomburro. The name “chank” is derived from shankha, meaning “divine conch”, referring to the Indian species Turbinella pyrum. Hindus considered the rare left-handed form of this shell to be sacred.

Description: The West Indian Chank Shell is one of the largest gastropod species in the Atlantic Ocean. It is a heavy, spindle-shaped shell, consisting of six whorls. They have eight to ten prominent ribs running the length of the shell, forming knobs on the shoulders of the whorls. The spire is high and marked with fine spiral threads, which extend to the body whorl. The aperture is large and elongate and the siphon canal is open. There are three or four folds on the columella. The exterior of the shell is creamy white, though it is often covered by a dark brown or tan periostracum; the interior is pink or orangish. The operculum is thick, horn-like, and too small to cover the aperture. West Indian Chank Shells reach a maximum 36 cm (14 inches) in length though some sources state that they reach just under 50 cm ( 20 inches).

Habitat and Distribution: West Indian Chanks are found on mud, sand, and rock substrates, and in seagrass beds, subtidally to depths up to 81 m (266 feet). They are a tropical Western Atlantic species that are found in all Mexican waters of the Atlantic Ocean with the exception that the are absent from north of the State of Veracruz along the northwest coast of the mainland in the Gulf of Mexico.

Ecology and Behavior: West Indian Chanks are predators that feed primarily on bivalves and worms. They are gonochoric and reproduce sexually, with internal fertilization. The eggs are laid in protective capsules. Their engagement in any type of commensal, parasitic, or symbiotic relationship has not been formally documented, although their empty shells are used by the Giant Hermit Crab, Petrochirus diogenes, for housing. From a conservation perspective they have not been formally evaluated. West Indian Chank are edible and are a major component in  Caribbean conch fisheries.

Synonyms:  Murex scolymus, Turbinella scolymus, Turbinella umbillicaris, and Voluta angulata