Green Crab

Green Crab, Callinectes bellicosus

Green Crab, Callinectes bellicosus, Female. Crab caught from coastal waters off Loreto, Baja California Sur, July 2024. Size: 6.4 cm (2.5 inches) x 3.2 cm (1.3 inches).

Green Crab, Male, Callinectes bellicosusCrab collected from coastal waters off Puerto Adolfo Lopez Mateos, Baja California Sur, October 2017. Wing span: 8.0 cm (3.1 inches); shell 2.8 cm (1.1 inches) x 2.4 cm (0.9 inches).

Green Crab, Callinectes bellicosus, Male. Crab purchased at Soriana’s Mercado, Cabo San Lucas, Baja California Sur, December 2011. Size: 15.1 cm (5.9 inches) x 7.5 cm (3.0 inches). Identification courtesy of Christine Ewers, Athens, Georgia.

Green Crab, Callinectes bellicosus. An interesting string of  Green Crabs caught at night in the Mangrove Estero, Agua Verde, Baja California Sur, April 2018. Catch and photograph courtesy of Barry Mastro, Escondido, California.

General information: The Green Crab, Callinectes bellicosus, is a common member of the Portunidae Family of Swimming Crabs, that is also known as the Warrior Swim Crab and in Mexico as jaiba azul or jaiba cruda. The family has thirteen individual Genus of which five Genus with sixteen individual species are found in Mexican waters. The swim crabs are very commercially important; they are collected by trawl nets primarily at night in the months of September, October and November. With an increase in the demand for swimming crab meat in the United States, Mexico has become one of the major global sources exporting 18,000 tons of crab meat valued at $170 million annually of which 60% comes from the Sea of Cortez. Crab fishing is heavily regulated in the states of Baja California Sur, Sinaloa, Sonora via permits, size limits, annual collection limits, bans on the retention of egg bearing females, type of bait and fishing gear employed. At present the fishery is believed to be at “maximum sustainable yield” and an increase in fishing efforts will not be sanctioned. These crabs are sold fresh in most of the major Mexican supermarkets with prices of just under $2 per pound. This crab is of great importance to the Mexican economy along the Pacific Coast being the most common swim crab in the Sea of Cortez. The Green Crab is considered to be one of the most invasive marine species due to its lack of predators and its aggressive behavior when hunting outcompeting other species.

Identification:  The Green Crab is a decapod with ten limbs. Swim Crabs are colorful and active crabs that are among the few crabs that are swift and agile swimmers. They swim sideways utilizing their paddle-like fifth pair of (dactyl) legs that rotate like propeller blades. However, they are essentially bottom dwellers. They have a streamlined profile that allows for rapid swimming and long pincers armed with sharp spines to snag food. The Green Crab has a uniquely shaped shell with nine spines along the edges of which the ninth is twice as long as the eighth. The shell between the eyes is straight and without teeth and the eyes have short stalks. The claws have one or two teeth and the cheliped usually has 3-4 spines on the inside margin. The abdomen of the male is “T” shaped while the abdomen of the female is an equilateral triangle. They are dimorphic, with the male Green Crabs being larger than the females, 17 cm (6.7 inches) to 14 cm (5.5 inches). Breeding is governed by water temperature (21 to 32oC) and occurs from March thru September. The Green Crab is quite similar to and can be easily confused with the Arched or Cuata Swim Crab, Callinectes arcuatus  (ninth spine is four times the length of the eighth; the cheliped has a large spine) they can be distinguished by the six “teeth” running down the carapace behind the eyes as well as blue legs.

Habitat and Range: The Green Crabs are found intertidally to depths up to 23 m (75-feet) within bays and lagoons along the coast from Los Angeles, California south to Peru. During periods of elevated water temperatures they migrate to deeper waters. Older individuals that have not molted usually have barnacles attached to their shells. they tend to burry themselves in the sandy and muddy bottoms, with some juvenile individuals being found as deep as 50 m (164 feet).

Diet: The Green Crabs are carnivores that feed on small invertebrates including mollusks and other smaller crustaceans.

Conservation Status:  From a conservation perspective the Green 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. They are prone to overfishing on a regional basis.

Synonyms:  Callinectes ochoterenai and Lupa bellicosa