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crab

crab

The Columbia Encyclopedia, 6th ed. | 2011 | Copyright

crabcrustacean with an enlarged cephalothorax covered by a broad, flat shell called the carapace. Extending from the cephalothorax are the various appendages: five pairs of legs, the first pair bearing claws (or pincers), are attached at the sides; two eyes on short, movable stalks, two short antennules, two longer antennae, and numerous mouthparts are attached at the front; at the rear the tiny abdomen is bent under the cephalothorax.

The abdomen of the female, wider and flatter than that of the male, forms an apronlike structure that continuously circulates water over the eggs that are carried on her underside. The free-swimming larva, which hatches in about two weeks, is easily recognized by the large spine that projects from its carapace. After several molts, the young crab settles to the bottom and begins to take on adult features.

Crabs are chiefly marine, but some are terrestrial for long periods. They are omnivorous; some are scavengers and others predators. Although they are capable of locomotion in all directions, crabs tend to move sideways; swimming crabs have the last pair of legs flattened to form paddles.

The blue crab of the Atlantic coast of the United States is a swimming crab that is much used for food. It is marketed as a soft-shelled crab after it has molted and before the new shell has hardened. Females of the oyster and mussel crabs live inside the shells of bivalve mollusks. Often seen scurrying about near their burrows in muddy banks are the fiddler crabs , the males of which have one much enlarged claw used in defense and in courtship rituals. The sand, or ghost, crabs build burrows high up on the sand into which they seem to vanish. The sluggish, long-legged spider crabs are often disguised by the algae, barnacles, and sea anemones that attach themselves to the carapace. The giant spider crab of Japan, the largest living arthropod, has legs about 4 ft (22 cm) long and a carapace over 1 ft (30 cm) wide. The closely related kelp crabs are found in kelp beds in the Pacific. The name king crab is applied to the largest (up to 20 lb/9 kg) of the edible crabs, species native to the N Pacific and marketed frozen, canned, or fresh; the red king crab has been introduced into the Barents Sea.

True crabs are classified in the phylum Arthropoda , subphylum Crustacea, order Decapoda. Although the many species of true crabs are similar in appearance, DNA evidence suggests that that similarity is a result of convergent evolution among several groups of sometines only distantly related decapods. The horseshoe crab , which also is called by the name king crab, is not a crustacean, and the hermit crab , although a crustacean, is not a true crab.

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crab

The Oxford Pocket Dictionary of Current English | 2009 | Copyright

crab1 / krab/ • n. 1. a crustacean (order Decapoda, class Malacostraca) with a broad carapace, stalked eyes, and five pairs of legs, the first pair of which are modified as pincers. ∎  the flesh of a crab as food. ∎  (the Crab) the zodiacal sign or constellation Cancer. 2. (also crab louse) a louse (Phthirus pubis, family Pediculidae) that infests human body hair, esp. in the genital region, causing extreme irritation. ∎  (crabs) inf. an infestation of crab lice. 3. a machine for lifting heavy weights. • v. 1. [tr.] move sideways or obliquely. 2. [intr.] fish for crabs. DERIVATIVES: crab·ber n. crab·like / -ˌlīk/ adj. & adv. crab2 • n. short for crab apple. crab3 • n. inf. an irritable person. • v. (crabbed , crab·bing ) inf. 1. [intr.] grumble, typically about something petty. 2. [tr.] act so as to spoil: you're trying to crab my act.

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crab

The Oxford Companion to Ships and the Sea | 2006 | Copyright

crab, a capstan but without a drumhead, and in which the bars were inserted right through the top of the barrel instead of into pigeon-holes in the upper perimeter (drumhead) as in a capstan proper; the holes for the bars in a crab being in different planes. In the days of sail it was used for any heavy lifting work on board in exactly the same way as a capstan but sometimes extemporized for use in positions where the fall of the purchase used for lifting a weight could not be led to an existing winch or capstan. See also crustacea.
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crab

World Encyclopedia | 2005 | Copyright

crab Flattened, triangular, or oval ten-legged crustacean covered with a hard shell. Primarily marine, some crabs are found in freshwater and a few are terrestrial. Their short abdomen, often called a tail, is bent under. Most have a pair of large foreclaws, a pair of movable eyestalks and a segmented mouth. Crabs usually move sideways. Size: pea-sized to 3m (12ft). Order Decapoda.
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crab

A Dictionary of Food and Nutrition | 2005 | | Copyright

crab Shellfish; Cancer and Carcinus spp.; king crab is Limulus polyphemus. A 100‐g portion (500 g with shell) is a rich source of protein, niacin, zinc, copper, and selenium; a good source of iron; a source of vitamins B2 and B6; contains 400 mg of sodium and 5 g of fat, of which 13% is saturated; supplies 130 kcal (545 kJ).
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DAVID A. BENDER. "crab." A Dictionary of Food and Nutrition. 2005. Encyclopedia.com. 26 May. 2012 <http://www.encyclopedia.com>.

DAVID A. BENDER. "crab." A Dictionary of Food and Nutrition. 2005. Encyclopedia.com. (May 26, 2012). http://www.encyclopedia.com/doc/1O39-crab.html

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crab

The Concise Oxford Dictionary of English Etymology | 1996 | | Copyright

crab 1 crustacean of the tribe Brachyura. OE. crabba = (M)LG., (M)Du. krabbe, ON. krabbi, rel. to OS. krēƀit, MLG. krēvet, (M)Du. kreeft, OHG. krebiz, krebaz (G. krebs), and to MLG. krabben, ON. krafla scratch, claw.
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T. F. HOAD. "crab." The Concise Oxford Dictionary of English Etymology. 1996. Encyclopedia.com. 26 May. 2012 <http://www.encyclopedia.com>.

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crab

The Concise Oxford Dictionary of English Etymology | 1996 | | Copyright

crab 2 wild apple. XIV. contemp. with north. scrab (prob. of Scand. orig.; cf. Sw. dial. skrabba wild apple), of which it may be an alteration by assoc. with prec. or CRABBED.
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crab

The Concise Oxford Dictionary of English Etymology | 1996 | | Copyright

crab 3 (of hawks) scratch, claw XVI; (sl.) find fault with, ‘pull to pieces’ XIX. — (M)LG. krabben (see CRAB 1).
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Crab

The Concise Oxford Companion to English Literature | 2003 | | Copyright

Crab, in Shakespeare's Two Gentlemen of Verona, Launce's dog.
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MARGARET DRABBLE and JENNY STRINGER. "Crab." The Concise Oxford Companion to English Literature. 2003. Encyclopedia.com. 26 May. 2012 <http://www.encyclopedia.com>.

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MARGARET DRABBLE and JENNY STRINGER. "Crab." The Concise Oxford Companion to English Literature. 2003. Retrieved May 26, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O54-Crab.html

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Crab

The Oxford Dictionary of Phrase and Fable | 2006 | | Copyright

Crab the zodiacal sign or constellation Cancer.
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ELIZABETH KNOWLES. "Crab." The Oxford Dictionary of Phrase and Fable. 2006. Encyclopedia.com. 26 May. 2012 <http://www.encyclopedia.com>.

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crab

Oxford Dictionary of Rhymes | 2007 | Copyright

crab •blab, cab, confab, crab, Crabbe, dab, drab, fab, flab, gab, grab, jab, kebab, lab, nab, scab, slab, smash-and-grab, stab, tab •Moab • baobab • rehab • pedicab •minicab • taxicab • Skylab

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