Pacific Crown Conch Shell, Melongena patula

Pacific Crown Conch Shell, Melongena patula. Shell collected off the beach at Punta Chivato, Baja California Sur, December 2022. Size: 8.2 cm (2.8 inches) x 6.2 cm (2.4 inches) x 9.0 cm (3.5 inches). Collection, photographs and identifications courtesy of Colin Campbell, DVM, Punta Chivato, Baja California Sur.

Pacific Crown Conch Shell, Melongena patula. Shell collected off the beach at Punta Chivato, Baja California Sur, March 2022. Size: 13 cm (5.1 inches) x 9 cm (3.5 inches) x 6 cm (2.4 inches). Photographs courtesy of Colin Campbell, DVM, Punta Chivato, Baja California Sur.

Pacific Crown Conch Shell, Melongena patula. Shell provided by the commercial fishermen of Todos Santos, Baja California Sur, March 2018. Size: 18.4 cm (7.2 inches) x 13.0 cm (5.1 inches) x 9 cm (3.5 inches).

Pacific Crown Conch Shell, Melongena patula. Shell collected off the beach at Punta Chivato, Baja California Sur, December 2021. Size: 18 cm (7.0 inches) x 13 cm (5.2 inches) x 9 cm (3.5 inches). Collection courtesy of Kathy Farley, Punta Chivato. Photographs courtesy of Colin Campbell, DVM, Punta Chivato, Baja California Sur.

Phylogeny: The Pacific Crown Conch, Melongena patula (Broderip and G.B. Sowerby I, 1829), is a gastropod mollusk that is a member of the Melongenidae Family of Crown Conchs and Melon Conch Shells. The genus Melongena is one of eight genera in this family, and there are four species in this genus. They are also known as the Prince Crown Conch and the Spreading Crown Conch and in Mexico as Melongena Coco.

Description: The Pacific Crown Conch shell is pear-shaped with about 5 whorls and a low spire. The body whorl is very large. The shoulders may be smooth or have knobs or spires. The  aperture is wide and runs the length of the majority of the shell. The inner lip is polished and folded at the base. The exterior of the shell is sculpted with fine spiral cords. The exterior of the shell is chestnut with darker brown, yellow or white spiral banding. The interior is white and can have yellow and pink tinges. The shell is usually covered with a thick brown fibrous periostracum. The operculum is thick and corneous. The foot of the living animal is yellow, with brown spots. Pacific Crown Conch shells reach a maximum of 25 cm (9.8 inches) and  18 cm (7.1 inches) in height.

Habitat and Distribution: Pacific Crown Conchs are found on sand and mud and are often associated with mangroves. They live in the intertidal zone, and at depths up to 10 m (35 feet). They are a subtropical to tropical Eastern Pacific species. In Mexican waters they are found throughout the Gulf of California, and south to Guatemala. They have not been documented from the west coast of the Baja Peninsula, noting that the pictured shell above was collected in coastal waters off Todos Santos, Baja California Sur, indicative of a slight presence along the extreme southwest coast of the Baja Peninsula.

Ecology and Behavior: Pacific Crown Conchs are predators that feed primarily on bivalves. They are gonochoric and reproduce sexually, with internal fertilization. The eggs are laid in protective capsules. 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.

Synonym: Pyrula patula.