Fat Dove Shell, Columbella major

Fat Dove Shell, Columbella major. Shell collected off the beach in the greater Los Cabos area, Baja California Sur, June 2018. Size: 2.7 cm (1.1 inches) x 1.7 cm (0.7 inches).

Phylogeny: The Fat Dove Shell, Columbella major (G.B. Sowerby I, 1832), is a gastropod mollusk that is a member of the Columbellidae Family of Dove Shells. The genus Columbella is one of seventy-seven genera in this family, and there are eighteen species in this genus.

Description: The Fat Dove Shell is fairly small and has a diamond-shaped outline.  The top of the body whorl is extra wide, forming a “spout” at the aperture. The aperture has dentition on both sides. The spire is fairly tall, and bluntly pointed. They exterior of the shell is smooth and can vary from tan to dark brown in color. They are covered with white spots and botches, which are more numerous at the anterior end. These spots may form a pattern, following along the whorl. The interior is white. They are covered with a rough periostracum. Fat Dove shells reach a maximum of 3.3 cm (1.3 inches) in length and 2.1 cm (0.8 inches) in height.

Habitat and Distribution: Fat Dove Shells are found on, and under, rocks in the intertidal zone. They are a tropical Eastern Pacific species. In Mexican waters they range from the greater Cabo San Lucas area, Baja California Sur to Guatemala, including the extreme southern portion of the Gulf of California. They have not been documented along the west coast of the Baja Peninsula.

Ecology and Behavior: Fat Dove Shells are omnivorous grazers.  They are preyed upon by crabs, fish, predatory mollusks and shorebirds. These shells 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. 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:  Colombella gibbosa  and Columbella gibbosa.