Scaled False Triton Shell, Phyllocoma scalariformis

Scaled False Triton Shell, Phyllocoma scalariformis. Shell courtesy of the commercial fishermen of the greater Los Cabos area, Baja California Sur, May 2008. Size: 3.0 cm (1.2 inches) x 2.0 cm (0.8 inches).

Phylogeny: The Scaled False Triton Shell, Phyllocoma scalariformis (Broderip, 1833), is a gastropod mollusk that is a member of the Muricidae Family of Rock Shells.  The genus Phyllocoma is one of one hundred ninety-eight genera in this family, and there are five species in this genus. They are also known as the Staircase Phyllocoma, and in Mexico as Filocoma Escalera.

Description: Scaled False Triton Shells are medium sized, with four to seven convex whorls. They have a high spire, and a large aperture with flared lips. There are open canals at both ends of the aperture. The shell exterior is sculpted with strong spiral ridges and axial ribs, giving the shell a lattice-like appearance. Some individuals have pronounced, discontinuous, varices. The shell is white in color. Scaled False Triton Shells reach a maximum of 3.8 cm (1.5 inches) in length and 2.5 cm (1.0 inch) in height.

Habitat and Distribution: Scaled False Triton Shells are found on rocks and on sand between rocks. They live in the intertidal zone, and to depths up to 15 m (49 feet). They are a subtropical to tropical Eastern Pacific species. In Mexican waters they range from range from Todos Santos, Baja California Sur to Guatemala, including the Tres Marias Islands. They are found in the Gulf of California as far north as San Carlos Bay, Sonora.

Ecology and Behavior: Scaled False Triton Shells are a poorly studied and understood species. There is very limited documentation of their diet, predation, reproduction or ecosystem interactions. Other species in Family Muricidae are predators that feed primarily on shelled invertebrates. They are gonochoric and reproduce sexually, with internal fertilization.  There is no mention in the available literature of them engaging in any types of parasitic, commensal, or symbiotic relationships. They are a fairly rare species and sought by shell collectors. From a conservation perspective they have not been formally evaluated.

Synonyms:  Phyllocoma (Phyllocoma) scalariformis and Triton scalariformis.