blue crab

 

common name for a crustacean, Callinectes sapidus, found on the S Atlantic and Gulf coasts of North America. The blue crab is a member of the family of swimming crabs known as the Portunidae and is characterized by a broad, semitriangular carapace (shell) covering the thorax, by a narrow abdomen tucked under its body, and by five pairs of appendages called pereiopods, of which the first two bear large claws (chelae) and the last two are flattened paddles modified for swimming. It is the most common edible crab of the Atlantic coast, and several million pounds are fished commercially by trapping or trawling each year. It is sold both as the hard-shell variety and as the familiar delicacy known as the soft-shelled crab. In the hard-shell form, the crab is in an intermolt phase (between molts) and the exoskeleton is fully hardened (sclerotized). In its soft-shell stage, the crab is in the phase just after the molt but before the exoskeleton has hardened. Since, in nature, the crab retires to secluded areas at the time of the molt and is thus difficult to collect, commercial fishermen collect the crabs at the so-called peeler stage, which occurs two to three days before the molt. The crabs are then held in pens, on floats in the water, until just after the molt, when they are marketable. The ovaries of the female begin to develop only after mating has taken place. The female carries the young under her abdomen until they hatch as tiny larvae, which are only ¹/₂₅ in. (0.1 cm) long. The crabs molt many times and grow to 7 in. (17.8 cm) in about 200 days. Blue crabs are classified in the phylum Arthropoda, subphylum Crustacea, class Malacostraca, order Decapoda, family Portunidae.

Blue crab
Scientific classification
Kingdom: Animalia Phylum: Arthropoda Subphylum: Crustacea Class: Malacostraca Order: Decapoda Suborder: Pleocyemata Infraorder: Brachyura Family: Portunidae Genus: Callinectes Species: C. sapidus
Binomial name
Callinectes sapidus Rathbun, 1896

The blue crab (Callinectes sapidus, from the Greek calli="beautiful", nectes="swimmer", and Latin sapidus="savory") is a crustacean found in the waters of the western Atlantic Ocean and Gulf of Mexico, which is the Maryland State Crustacean and the subject of an extensive fishery.^[1]

Distribution and ecology

The blue crab is native to the western edge of the Atlantic Ocean from Nova Scotia to Argentina.^[2] It has been introduced (via ballast water) to Japanese and European waters, and has been observed from the Baltic Sea, North Sea, Mediterranean Sea and Black Sea.^[3]

The natural predators of the blue crab include eels, drum, spot, trout, some sharks, and cownose sting rays. The blue crab is an omnivore, eating both plants and animals. Blue crabs typically consume thin-shelled bivalves, annelids, fish, plants and nearly any other item they can find, including carrion.

Commercial importance

The Chesapeake Bay, shared by Maryland and Virginia, is famous for its blue crabs, and they are one of the most important economic items harvested from it. In 1993, the combined harvest of the blue crabs was valued at around 100 million US Dollars. Over the years the harvests of the blue crab dropped; in 2000, the combined harvest was around 45 million dollars. In 19__^{[citation needed]} the Maryland Department of Natural Resources created stricter guidelines for harvesting blue crabs to help increase populations. These include raising the legal size from 5 to 5¼ inches (from 12.7 to 13.3 cm) and limiting the days and times they may be caught.

While blue crabs remain a popular food in the Chesapeake Bay area, the Bay is not capable of meeting local demand. Crabs are shipped in from North Carolina, Louisiana, Florida and Texas to supplement the local harvest.

Harvesting techniques

Blue crabs are often harvested by using a "crabpot", although line crabbing (using a baited line similar to fishing) is also popular among amateur "crabbers". The design of a crabpot can vary widely, but nearly all varieties are made out of wire mesh (older designs of wood and wire also exist, as well as all metal varieties). The crabpot is usually cubical or prismatic in shape (although cylindrical designs are also used). The crabpot contains two to four "entrances" for the crabs that prohibit exit. These may be as simple as hinged panels that are drawn closed as the crabpot is raised from the water, or may be in the form of a tapered or conical aperture that allows the crab to squeeze through in one direction only. A crabpot is baited with any of several types of meat, including bunker, bluefish, chicken or eel. The bait is placed in a holding spot (often a separate meshed enclosure preventing the crabs from completely removing the bait) in the middle or bottom of the pot.

The pots are distributed throughout the crabber's harvesting area and are checked approximately once a day for captures or depleted bait. Crabs that are caught are removed, and the pot is re-baited for the next day. Some people^{[citation needed]} add the catch from each pot to a "keeper pot" that holds the live crabs until a substantial harvest is accumulated. When the keeper pot is appreciably full, the contents are prepared for a "crab feast" or for sale. The keeper pot also allows a crabber to fatten up the crabs until the time they are cooked.

The largest male crabs are known as "jimmies", and mature females as "sooks" or "sookies". Immature female crabs are known as "sallies" or "she-crabs".^[1]

Preparation

Blue crabs are most often eaten in the hard shell, after steaming them in large pots with water, vinegar and seasoning (Old Bay Seasoning is a popular variety in Maryland). The cooked crabs are cracked by hand, and the meat pulled out and eaten directly, often with butter or additional seasoning. The picked meat, especially the large chunks from the backfin area, can also be used to make crab cakes, crab soup, or other dishes.

Crabs caught just after molting (before the new shell has had time to harden) are prepared as soft shell crabs. Soft shell crabs are prepared by first cutting out the gills, face, and guts. The crab is then battered in flour, egg, and seasoning, then fried in oil until crispy. The result can be served as an entrée, or in a sandwich.

Blue crabs average 15% edible meat, and that meat is high in vitamin B₁₂. Just three ounces of crab meat contain a full day's allowance of the vitamin.

References

1. ^ ^{a b} Maryland State Crustacean. Maryland State Archives (2005-12-27).
2. ^ Callinectes sapidus. Smithsonian Marine Station at Fort Pierce (2004-10-11).
3. ^ Callinectes sapidus. CIESM: The Mediterranean Marine Research Network (August 2006).

External links

• The Maryland Blue Crab Blue crab fact and information website.

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