The Tasmanian giant crab (Pseudocarcinus gigas), also known as the giant deepwater crab, giant southern crab, queen crab, or bullcrab, is a very large species of crab that resides on rocky and muddy bottoms in the oceans off Southern Australia.[1] It is the only extant species in the genus Pseudocarcinus.[2]
The Tasmanian giant crab lives on rocky and muddy bottoms in the oceans off Southern Australia on the edge of the continental shelf at depths of 20-.[1] It is most abundant at 110- in the summer and 190- in the winter.[1] The seasonal movements generally follow temperature as it prefers 12-.[1] The full temperature range where the species can be seen appears to be 10-.[3]
The Tasmanian giant crab is one of the largest crabs in the world, reaching a mass of 17.6kg (38.8lb) and a carapace width of up to 46cm (18inches).[4] Among crabs, only the Japanese spider crab (Macrocheira kaempferi) can weigh more.[3] Male Tasmanian giant crabs reach more than twice the size of females,[5] which do not exceed 7kg (15lb).[4] Males have one normal-sized and one oversized claw (which can be longer than the carapace width[3]), while both claws are normal-sized in females.[4] This crab is mainly whitish-yellow below and red above; the tips of the claws are black.[6] Small individuals are yellowish-and-red spotted above.[3]
The Tasmanian giant crab feeds on carrion and slow-moving species, including gastropods, crustaceans (anomura and brachyura) and starfish.[1] [5] Cannibalism also occurs.[1] They breed in June and July, and the female carries the 0.5–2 million eggs for about four months.[5] After hatching, the planktonic larvae float with the current for about two months before settling on the bottom.[3] The species is long-lived and slow-growing; juveniles moult their carapace every three-four years and adult females about once every nine years.[3] [4] This greatly limits the breeding frequency, as mating is only possible in the period immediately after the old carapace has been shed, and the new is still soft.[4]
The Tasmanian giant crab has been commercially fished in Tasmanian waters since 1992 and a minimum size was established in Australia in 1993.[5] Fishing is typically by pots in water deeper than 140m (460feet).[4] Following concerns surrounding the sustainability of catch numbers, the total allowable catch was adjusted for 2024/25 quota year to 20.7t.[7] valued at about A$2 million.[7] The Tasmanian giant crab is very long-lived and slow-growing, making it vulnerable to overfishing.[5] Before export, they are sometimes kept alive in tanks with water that is 10-.[1]
. N. Coleman . Neville Coleman . 1991 . Encyclopedia of Marine Animals . Blandford, Villiers House . 107. 0-7137-2289-4.