an outstandingly successful form of crustacean, so much so that since the first crabs evolved in the Jurassic the number of species has multiplied to such an extent that within the order Decapoda (which includes lobster, prawn, shrimp) some 4,500 of the 8,500 species are crabs.
The typical crab is thought of as a creature which scuttles sideways across the sea bottom or beach; and many crabs answer to this description. However, there are also swimming crabs and land crabs, and the range of sizes and configurations is huge. The tiny oyster (pea) crab is the size of a pea, whereas the giant Japanese spider crab may measure 3.6 m (12′) from claw tip to claw tip. The constant feature is possession of two claws and eight walking or swimming legs or ‘feet’, and that the whole creature is, like other crustaceans, contained within a hard exoskeleton which serves as protective armour except at those times when it has to be shed, as its occupant grows, and replaced by a new and larger one.
The most important crab fisheries take place in the N. Pacific, especially the Bering Sea, where king crabs of the genus Paralithodes and snow crabs of the genus Chionoecetes are taken in larger quantities than any other groups. These are processed in one way or another before reaching the consumer.
The W. Atlantic, including the Gulf of Mexico and the S. American coast down to Brazil, is another important region for crab fisheries, especially that for the blue crab, centred in Chesapeake Bay. The blue crab is third in catch by volume, worldwide.
The Pacific coastal waters of N. America yield the Dungeness crab, which, with its E. Atlantic opposite number, the feebly named but delicious ‘edible crab’, constitutes the fourth largest group.
It may be that a lack of full statistics for crab catches in SE Asia has prevented the regional group consisting of the mangrove crab (Scylla serrata) and swimming crabs (Portunus spp) from attaining their proper place in the league table. Thailand is, however, recognized as the third largest producer (after the USA and Japan), with the former Soviet Union and Brazil competing for fourth place.
Some crabs, such as the Dungeness and the European edible crab, yield meat from both claws/legs and body. The blue crab provides mainly body meat. Others, notably the king and snow crabs, furnish leg meat.
There is a similarity of flavour and texture between the white (claw/leg) meat of a crab and lobster meat. The latter is held in higher esteem, at least among those who can afford to buy it; but partisans of the more plebeian crabmeat challenge this, declaring that it can be just as good, or even better.
For particular species or groups, see blue crab; crab, common; dungeness crab; fiddler crab; hermit crab; horseshoe crab; kona crab; lagoon crab; land crabs; mangrove crab; oyster crab; red crab; rock crab; sand crab; shore crab; snow crab; spider crab; stone crab; swimming crabs.
Alan Davidson was a distinguished author and publisher, and one of the world's best-known writers on fish and fish cookery. In 1975 he retired early from the diplomatic service—after serving in, among other places, Washington, Egypt, Tunisia, and Laos, where he was British Ambassador—to pursue a fruitful second career as a food historian and food writer extraordinaire. Among his popular books are Seafood of South-East Asia, North Atlantic Seafood, and Mediterranean Seafood. In 2003, shortly before his death, he was awarded the Erasmus Prize for his contribution to European culture.
