The brown box crab (Echidnocerus foraminatus) is a king crab that lives from Prince William Sound, Alaska to San Diego, California,[2] at depths of 0–547 metres (0–1,795 ft).[3] It reaches a carapace length of 150 millimetres (5.9 in) and feeds on bivalves and detritus. The box crab gets its name from a pair of round tunnel-like openings that form between the claws and adjacent legs when the animal folds its limbs up against its body.[4] Both claws, and their adjacent legs, have matching half-circle notches in them that line up to create a circle-shaped opening when the limbs are tightly pulled against one another.[4] This tubular round opening is called a foramen. The crab often lies buried in the sediment, and the two foramens in the chelipeds allow water into the gill chamber for respiration.[2] The gill chamber is also sometimes used by the commensal fish Careproctus to hold its eggs.[5]
Fisheries
The brown box crab has been fished in California since at least 1984.[6] Take was minor and largely incidental until the mid 2010s, when landings by mass increased five-fold in 2017 relative to 2016[7] and remained above 20.5 t (45,000 lb) until 2023.[6] In 2019, the California Department of Fish and Wildlife launched an experimental fishery for brown box crabs.[7]
References
^Stimpson, William (1859). "Notes on North American Crustacea, no. 1". Annals of the Lyceum of Natural History of New York. 7 (11): 49–93.
^Peden, Alex E.; Corbett, Cathryn A. (1973). "Commensalism between a liparid fish, Careproctus sp., and the lithodid box crab, Lopholithodes foraminatus". Canadian Journal of Zoology. 51 (5): 555–556. doi:10.1139/z73-081.