White-striped Chiton Shell, Chiton albiolineatus

White-striped Chiton Shell, Chiton albiolineatus. Size: 2.5 cm (1.0 inch). Underwater photograph courtesy of Ron Woheau, Zihuantanejo, Guerrero, January 2019.

White-striped Chiton Shell, Chiton albiolineatus. Size: 2.5 cm (1.0 inch). Underwater photograph and identification courtesy of Ron Woheau, Zihuantanejo, Guerrero, January 2020.

Phylogeny: The White-striped Chiton Shell, Chiton albolineatus (Broderip and G.B. Sowerby I, 1829) is a member of  Chitonidae Family of True Chiton Shells. The genus Chiton is one of fourteen genera in this family, and there are twenty-one species in this genus. In Mexico they are known as Quitón Lineas Blancas. The species name albolineatus comes from Latin, meaning “white-lined” or “white-striped.”

Description: The White-striped Chiton Shell is elongated with equally rounded ends and fairly straight sides. They are somewhat flattened with smooth plates. The radial areas are black with striking, white, radial lines. The central area of the shell may be violet gray, violet brown or greenish, with a lengthwise, black, center line. The girdle is gray to greenish, with white to light bluish-gray scales. The scales have brown borders. White-striped Chiton Shells reach a maximum of 5.5 cm (2.25 inches) in length.

Habitat and Distribution: White-striped Chiton Shells are found on, and under, rocks and stones in the intertidal zone and to a depth of 2.0 m (6 feet 6 inches). They are a subtropical to tropical Eastern Pacific species that is ENDEMIC to Mexico being found from Playa Barras de Piaxtla, Sinaloa in the Sea of Cortez, and from Todos Santos, Baja California Sur, south to La Crucecita, Oaxaca along the west coast of the Pacific Ocean.

Ecology and Behavior:  White-striped Chitons are a poorly studied and understood species. There is very limited documentation of their diet, predation, reproduction or ecosystem interactions. They are thought to be herbivorous grazers, but like other species in the Chitonidae Family they could be carnivores, detritivores, omnivores, or spongivores. They are gonochoric and reproduce sexually, through broadcast spawning. Their engagement in any type of commensal, parasitic, or symbiotic relationships has not been formally documented. From a conservation perspective the White-striped Chiton has not been formally evaluated. However, they are very common with a relatively wide distribution and should be considered to be of Least Concern.

Synonyms: Chiton (Chiton) albolineatus.