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 Shell 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 Tritons 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 that are found in all Mexican waters of the Pacific Ocean, including the Tres Marias Islands, with the exception that they are absent from north of Todos Santos, Baja California Sur, along the central and northwest coasts of the Baja Peninsula, and north of Bahía San Carlos, Sonora, in the Sea of Cortez.

Ecology and Behavior: Scaled False Tritons are a poorly studied and understood species. There is very limited documentation of their diet, predation, reproduction or ecosystem interactions. Other species in the Muricidae Family are predators that feed primarily on shelled invertebrates. They are gonochoric and reproduce sexually, with internal fertilization. Their engagement in any type of commensal, parasitic, or symbiotic relationship has not been formally documented. From a conservation perspective the Scaled False Triton has not been formally evaluated. However, they are fairly common with a relatively wide distribution and should be considered to be of Least Concern.

Synonyms:  Phyllocoma (Phyllocoma) scalariformis and Triton scalariformis.