Sally Lightfoot Crab

Sally Lightfoot Crab, Grapsus grapsus

The Sally Lightfoot Crab, Grapsus grapsus, is one of several crabs that are commonly referred to as “Sally Lightfoots.” They are members of the Grapsidae Family and known in Mexico as abuente negro. The “Sally Lightfoots” pictured herein are abundant in the Los Cabos area of Baja California Sur, Mexico. Most reports of Sally Lightfoots along all the coasts of Baja California Sur probably refer to Grapsus grapsus, which is most abundant and most photographed crab in its native habitat, the Galapagos Islands. These crabs found at Los Cabos actually resemble another crab called “Sally Lightfoot,” the Nimble Spray Crab, Percnon gibbesi, which is found predominantly in the Caribbean and other tropic waters around the world. Another “Sally Lightfoot” is the close relative of the Nimble Spray Crab, the Flat Rock Crab, Percnon plasissimum, which only reaches a size of one inch in diameter. The Sally Lightfoots found at Los Cabos vary in diameter from 5 cm (2 inches) to 10 cm (4 inches), but as named, they are virtually impossible to catch. They inhabit all coastal rock formations and have a unique ability to hang on the rocks when bombarded by large crashing waves. Sally Lightfoots feed on algae, dead fish, dead birds, and dead seals, and they have limited value other than they are a premiere fresh cut bait for which they are highly esteemed by local surf fishermen. These crabs are decapod crustaceans with 10 limbs, short eye stalks, powerful claws, and short antennae, with a large shell or carapace covering their bodies. They are characterized by their omnipresence and their elusive tactics, which makes photography, collection, and accurate identification most difficult. The Sally Lightfoot Crab is the subject of much folklore, and was reported by the immortal Ray Cannon to be an “ornery, razor-packin’, ink-spittin’ Devil spawn of the beach, satanic creature.” Said John Steinbeck of this crab in The Log of the Sea of Cortez: “They seem to be able to run in all four directions; but more than this, perhaps because of their rapid reaction time they appear to read the mind of their hunter. Man reacts peculiarly but consistently in his relationship with Sally Lightfoot. His tendency eventually is to scream curses, to hurl himself at them, and to come up foaming with rage bruises all over his chest”  …. and empty handed.

An ideal bait for shore fishing around rocky structures on an early morning or late afternoon tide. Sally Lightfoots are virtually impossible to catch by one less agile and less skilled in the art. Young locals, with agile dexterity, can catch these elusive creatures by walking the rocks, dodging the waves, armed with a long stick. The older set make there collections under the cover of darkness when these crabs go pseudo-dormant.

Sally Lightfoot Crab, Female, Grapsus grapsus. Collected from a Tidal Pool, Km 17, El Tule, Baja California Sur, January 2018. Size: 7.2 cm (2.8 inches) x 6.0 cm (2.4 inches); wing span: 26 cm (10.2 inches).

Sally Lightfoot Crab, Grapsus grapsus. Collected at Km 21, Cabo Real, Baja California Sur, January 2011. Tuff to catch! It took two hours, armed with a bait net, to catch two specimens for photos. Size: 9.0 cm (3.5 inches) x 7.8 cm (3.1 inches).

Sally Lightfoot Crab, Grapsus grapsus. Caught taking a stroll on the beach of India Bay, Huatulco, Oaxaca, January 2018. Photo courtesy of Jason Quick, Winnipeg, Manitoba, Canada.