Shame-faced Heart Box Crab, Cryptosoma bairdii

Shamed-faced Heart Box Crab, Cryptosoma bairdii. Crab provided by the Commercial Fishermen of the greater Los Cabos area, Baja California Sur, November 2011. Size 2.6 cm (1.0 inch) x 2.5 cm (1.0 inch). Identification courtesy of Christine Ewers, Athens, Georgia.

 

General information: The Shamed-faced Heart Box Crab, Cryptosoma bairdii, is one of thirty-nine members of the Calappidae Family or Box Crabs known in Mexico as cangrejo cajeta bolas. In Mexico it is known as cangrejo cajeta bola. They are caught as a by-catch of shrimp trawlers and in the gill nets utilized for spiny lobsters.

Identification: The Shamed-faced Heart Box Crab is a chestnut brown with tinges of purple with orange and white streaked claws. The common name is derived from the pair of equal sized large claws that normally cover the face and the “heart” shaped shell. They have a shell that is slightly wider than it is long and its surface and branchial ridges are minutely granulated. The branchial ridges lack tuberculate warts. The Shamed-face Heart Box Crab reach a maximum of 5.0 cm (2.0 inches) in width.

Habitat and Range: The Shamed-faced Heart Box Crabs are found from Magdalena Bay south along the west coast of the Baja, throughout the Sea of Cortez and along the coast of the mainland south to Guatemala. They are a shallow water species found over sandy and mud bottoms at depths up to 200 feet.

Diet: The Shame-faced Heart Box Crab is a nocturnal omnivore consuming small invertebrates, algae and detritus.

Conservation Status:  From a conservation perspective the Shame-faced Box Crab has not been formally evaluated. However, they are common and of limited interest to most and should be considered to be of Least Concern. The Shamed-face Heart Box Crab are not abundant and small in stature and thus of limited interest.

Synonyms: Cyclois bairdi  and Cyclois bairdii var. atlantica