Grinning Tun Shell, Malea ringens
Grinning Tun Shell, Malea ringens, Juvenile. Size: 15.5 cm (6.1 inches) x 12.0 cm (4.7 inches). Shell provided by the commercial fisherman of the greater Los Cabos area, Baja California Sur, May 2015. Identification courtesy of Dr. Rick Batt, Coral Gables, Florida.
Grinning Tun, Malea ringens. Size: 4.6 cm (1.8 inches) x 3.3 cm (1.3 inches). Shell provided by the commercial fisherman of the greater Los Cabos area, Baja California Sur, May 2015.
Grinning Tun, Malea ringens. Shell provided by the commercial fishermen of the greater Punta Chivato area, Baja California Sur, December 2022. Size: 17.2 cm (6.8 inches) x 14.2 cm (5.6 inches) x 10.9 cm (4.3 inches). Photographs and Identification courtesy of Colin Campbell, DVM, Punta Chivato, Baja California Sur.
Phylogeny: The Grinning Tun, Malea ringens (Swainson, 1822), is a gastropod mollusk that is a member of the Tonnidae Family of Tun Shells. The genus Malea is one of three genera in this family, and there are three species in this genus. They are also known as the Pacific Cask Shell and in Mexico as Caracol Barril and Caracol Bola.
Description: Grinning Tuns are named for their aperture which looks like a large, toothy, smile. The shells are large, swollen and consist of five whorls, the spire is low, and the aperture is large. The outer lip of the aperture heavily toothed, and there is a deep groove in the middle of the inner lip. The exterior is sculpted with wide ridges that spiral down the whorls. The exterior of these shells are brown, yellowish-white or white in color. The interior may be yellowish or reddish in color. Grinning Tun Shells reach a maximum of 27.0 cm (10.6 inches) in length and 22.2 cm (8.8 inches) in height.
Habitat and Distribution: Grinning Tuns are found on and within sand substrate within the intertidal zone, and to depths up to 40 m (130 feet). They are a subtropical to tropical Eastern Pacific species that are found in Mexican waters of the Pacific Ocean from Magdalena Bay, Baja California Sur south to Guatemala. They are found throughout the Gulf of California.
Ecology and Behavior: Grinning Tuns are a poorly studied and understood species. There is very limited documentation of their diet, predation, reproduction or ecosystem interactions. Other species in Family Tonnidae are predators that feed primarily on bivalves, echinoderms, crustaceans, and even fish. They are gonochoric and reproduce sexually, with internal fertilization. The eggs are laid in masses of wide gelatinous ribbons. There engagement in any types of commensal, parasitic, commensal, or symbiotic relationships has not been formally documented. From a conservation perspective they have not been formally evaluated.
Synonyms: Buccinum ringens, Cassis ringens, Dolium (Cadium) dentatum, Dolium (Cadium) dentatum var. crassilabris, Dolium (Malea) ringens, Dolium crassilabre, Dollium dentatum, Dollium latilabre, Dollium personatum, Dollium plicosum, Dollium ringens, Malea (Malea) ringens, Malea crassilabris, Malea crassilabrum, Malea dentatum, Malea latilabris, and Tonna (Malea) ringens.