Eastern Pacific Giant Conch Shell, Titanostrombus galeatus
Eastern Pacific Giant Conch Shell, Titanostrombus galeatus. Shell collected from coast waters off the Santa Inez South Island, Baja California Sur, April 2022. Size: 20 cm (7.9 inches) x 15 cm (5.9 inches). Collection, photograph and Identification courtesy of Colin Campbell, DVM, Punta Chivato, Baja California Sur.
Eastern Pacific Giant Conch Shell, Titanostrombus galeatus. Shells pictured provided by the commercial fishermen of the greater Los Cabos area, Baja California Sur, December 2018. Both Size: 20 cm (7.9 inches) x 14 cm (5.4 inches) x 10 cm (3.9 inches).
Eastern Pacific Giant Conch Shell, Titanostrombus galeatus. Photograph taken of a mural found painted on the side of building in the Barrio Logan section of San Diego, California, May 2017.
Phylogeny: The Eastern Pacific Giant Conch, Titanostrombus galeatus (Swainson, 1823), is a gastropod mollusk that is a member of the Strombidae Family of True Conch Shells. The genus Titanostrombus is one of thirty-one genera in this family, and there are two species in this genus. They are also known as the Fiber Conch, the Galeate Conch and simply the Giant Conch and in Mexico they as Cobo Combute.
Description: Eastern Pacific Giant Conchs are aptly named with the shell being large, thick, and solid. They are possibly the heaviest of any shell in North America. The shell has a large body whorl and a low but sharply pointed spire. The aperture runs almost the entire length of the shell. The outer lip of the aperture is widely flared. Low ridges spiral down the body whorl, but they become less obvious in larger specimens. The exterior of the shell is often eroded and worm-eaten. These shells change color as they age: young shells tend to be white with brown to orange blotches or bands with white interiors; older shells are cream to reddish-brown with brownish-orange interiors. The shell is normally covered with a thick, fibrous periostracum. The Eastern Pacific Giant Conch Shells reach a maximum of 24.0 cm (9.4 inches) in length and 16.8 cm (6.6 inches) in height.
Habitat and Distribution: Eastern Pacific Giant Conchs are found on and within sand substrate in the intertidal zone, and to depths up to 30 m (100 feet). They are a subtropical to tropical Eastern Pacific species. In Mexican waters they range from Todos Santos, Baja California Sur to Guatemala. They are found throughout the Gulf of California, being more common in the southern portion.
Ecology and Behavior: Eastern Pacific Giant Conchs are grazers that feed primarily on algae and detritus. They are prey for crabs, octopuses, and fish. They are gonochoric and reproduce sexually, with internal fertilization. The eggs are laid in masses, on the sea floor, or on empty mollusk shells. There is no mention in the available literature of them engaging in any types of parasitic, commensal, or symbiotic relationships. Eastern Pacific Giant Conchs are edible and fished commercially. Their shell has also been used for centuries by the indigenous communities as a horn for communication. From a conservation perspective they have not been formally evaluated however they are fairly common with a relatively wide distribution and should be consider to be of Least Concern.
Synonyms: Lobatus galeatus, Strombus crenatus, Strombus galea, and Strombus galeatus.