Belcher’s Miter Shell, Subcancilla belcheri

Belcher’s Miter Shell, Subcancilla blecheri. Shell courtesy of the commercial fishermen of the greater Los Cabos area, January 2010. Size: 12.2 cm (4.8 inches) x 3.3 cm (1.3 inches).

Phylogeny: Belcher’s Miter, Subcancilla belcheri (Hinds, 1843), is a gastropod mollusk that is a member of the Mitridae Family of Miter Shells. The genus Subcancilla is one of thirty-six genera in this family, and there are eighteen species in this genus.

Description: Belcher’s Miter Shell is a large and sturdy. It that consists of eight to nine, flat-sided, whorls that are marked by wide, flat, spiral ridges. The exterior of the shell is white to beige in color and often covered by a dark greenish periostracum. Belcher’s Miter Shells can reach a maximum of 14.8 cm (5.8 inches) in length and 4.0 cm (1.6 inches) in height.

Habitat and Distribution: Belcher’s Miters are found on and within sand substrate at depths between 18 m (60 feet) and 55 m (180 feet). They are a tropical Eastern Pacific species that are found in all Mexican waters of the Pacific Ocean with the exception that they are absent from north of Magdalena Bay, Baja California Sur, along the central and northwest coasts of the Baja Peninsula and from north of La Paz, Baja California Sur, in the Sea of Cortez.

Ecology and Behavior:  Belcher’s Miters are predatory carnivores that feed on shelled invertebrates. They are gonochoric and reproduce sexually, with internal fertilization. They’re engagement in any type of commensal, parasitic, or symbiotic relationships has not been formally documented. From a conservation perspective Belcher’s Miter 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: Mitra belcheri and Mitra (nebulifera) belcheri.