Kiosque Rock Shell, Thaisella kiosquiformis

Kiosque Rock Shell, Thaisella kiosquiformis. Shell collected off the beach of Bahía Concepción, Baja California Sur, October 2019. Size: 6.1 cm (2.4 inches) x 4.0 cm (1.6 inches). Collection, photograph and identification courtesy of Bob Hillis, Ivins, Utah.

Phylogeny: The Kiosque Rock Shell, Thaisella kiosquiformis (Duclos, 1832), is a gastropod mollusk that is a member of the Muricidae Family of Rock Shells. The genus Thaisella is one of one hundred ninety-eight genera in this family, and there are ten species in this genus.

Description: Kiosque Rock Shells have an angular appearance and consist of five or six whorls. They have a high very prominent knobbed spire, with the knobs continuing down the body in low ridges. They have a very short siphon canal and a large aperture. There is a frilled area where the spire joins the body whorl. The exterior of the shell is gray to dark brown in color, with varying amounts of white streaking or blotching. The interior is brown, sometimes with white banding.  Kiosque Rock Shells reach a maximum of 6.5 cm (2.6 inches) in length and 4.4 cm (1.7 inches) in height.

Habitat and Distribution: Kiosque Rock Shells are often found in mangrove forests or on rocks, in mud in the intertidal zone, and to depths up to 10 m (35 feet). They are a subtropical to tropical Eastern Pacific species that are found in Mexican waters of the Pacific Ocean from from Magdalena Bay, Baja California Sur south to Guatemala.  They are found throughout the Gulf of California.

Ecology and Behavior: Kiosque Rock Shells are predators that feed primarily on bivalves, such as oysters. 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 consider to be of Least Concern.

Synonyms:  Purpura kiosquiformis, Thais (Stramonita) kiosquiformis, and Thais (Thaisella) kiosquiformis.