Swainson’s Miter Shell, Isara swainsonii

Swainson’s Miter Shell, Isara swainsonii. Shell courtesy of the commercial fishermen of the greater Los Cabos area, Baja California Sur, February 2010. Size: 9.4 cm (3.7 inches) x 2.1 cm (0.8 inches).

Swainson’s Miter, Isara swainsonii (Broderip, 1836), is a gastropod mollusk that is a member of the Mitridae Family of Miter Shells, that is also known at the Antillean miter.  The shell is large consisting of seven to eight flat-sided whorls with the body whorl being longer than the spire. The aperture is long and fairly straight and the shell is marked with fine spiral lines. The exterior of the shell is cream to buff in color and they are covered with a thin very dark periostracum; the interior is white. Swainson’s Miter shells reach a maximum of 16.5 cm (6.5 inches) in length and 9.4 cm (3.7 inches) in height.

Swainson’s Miters reside within sand substrate at depths from 5 m (15 feet) to 79 m (260 feet). They are found from the southern half of the Sea of Cortez to Peru.

Synonyms:   Mitra swainsoni and Mitra (fusimitra) swainsoni.