Taxonomic description

• Carapace grows up to 15 cm (6 in.) across, it is red-brown or tan in color with white and purple patches, and small spines. ^[2,3]
• When disturbed, it folds its legs and abdomen tightly together, so that it appears like a tight box or ball. ^[2]
• Has a calcified abdomen, with relatively short legs, and its fifth pair of legs are small and folded under the carapace, making it seem as if it only has four pairs of legs. ^[2,7]
• While buried, two circular holes (foramins) in the claws allow for water circulation to the gills. ^[2]
• Its large claw (usually the right) has blunt white teeth, while the small claw has sharp teeth. ^[2]

Distribution

• Range extends from Kodiak Island, Alaska, to San Diego, California. ^[3]

Life history

• Lives in aggregations, moves together, and molts at similar times within the aggregation. ^[7]
• In British Columbia, it has a biennial (two-year) breeding cycle; females molt and breed in mid-summer, brood eggs and larvae for 18 months, and release zoeae over ~69 days during the second winter/early spring (Feb-April) after breeding. The life cycle may be shorter and brooding may begin earlier (February) in Southern California. ^[2,7]
• Passes through four larval stages before becoming a juvenile and gaining the ability to walk. ^[2]

Habitat

• Resides in depths of low intertidal to ~600 m (1968 ft), but is usually found deeper than 18 m on muddy bottoms or on rocky faces over mud. ^[2,3]
• Scoops up mud to feed on bivalves and organic debris, and also feeds on brittle stars and sea urchins. ^[3]
• Is preyed upon by octopus, and may be parasitized by commensal organisms including snailfish, whose eggs and larvae can be found on crab gill filaments, and polychaete tubeworms, hydrozoans, and small bivalves on brooding and post-brooding females. ^[2,8]

Edible portions

• Meat inside the legs and claws are edible, and some meat in the body. Shells can also be used to make shellfish stock. ^[11]
• Up to 40% of the total weight is edible, with an average of 0.8 pounds of meat per crab (2 pounds whole). ^[19]

Description of meat

• Sweet, flakey, and buttery meat. ^[12]

Culinary uses

• Usually cooked whole, either by steaming or boiling. ^[13]
• Can substitute for most other crab recipes, and is relatively easy to pick. ^[11]
• For a recipe for Cantonese ginger and scallion crab that can substitute with box crab, visit Rasa Malaysia. ^[14]
• For an air fryer crab cake recipe, visit Cooks with soul. ^[15]

Nutritional information 

• Nutritional information for box crab could not be found; shown is Dungeness crab. ^[10] 

Toxicity report

• Domoic acid, a naturally occurring biotoxin, can occasionally occur in the guts of crab during harmful massive algal blooms. Check for warnings before buying fresh, and be sure to clean out guts before preparing.

Seasonal availability

• Available year round.