Caridea

Shrimp
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Crustacea
Class:	Malacostraca
Order:	Decapoda
Suborder:	Pleocyemata
Infraorder:	Caridea Dana, 1852
Superfamilies
Alpheoidea Atyoidea Bresilioidea Campylonotoidea Crangonoidea Galatheacaridoidea Nematocarcinoidea Oplophoroidea Palaemonoidea Pandaloidea Pasiphaeoidea Procaridoidea Processoidea Psalidopodoidea Stylodactyloidea

For other uses, see Caridea (disambiguation).

True shrimp are swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. Adult shrimp are filter feeding benthic animals living close to the sea bottom. They can live in schools and can swim rapidly backwards. Shrimp are an important food source for larger animals from fish to whales. They have a high resistance to toxins in polluted areas, and may contribute to high toxin levels in their predators. Together with prawns, shrimp are widely caught and farmed for human consumption.

Etymology: The term shrimp originated around the 14th century with the Middle English shrimpe, akin to the Middle Low German schrempen, and meaning to contract or wrinkle; and the Old Norse skorpna, meaning to shrivel up.

Life cycle

A nauplius of a shrimp.

Shrimp mature and breed only in a marine habitat. The females lay 50,000 to 1 million eggs, which hatch after some 24 hours into tiny nauplii. These nauplii feed on yolk reserves within their body and then undergo a metamorphosis into zoeae. This second larval stage feeds in the wild on algae and after a few days metamorphoses again into the third stage to become myses. At this stage the myses already begin to appear like tiny versions of fully-developed adults and feed on algae and zooplankton. After another three to four days they metamorphose a final time into postlarvae: young shrimp having all the characteristics of adults. The whole process takes about 12 days from hatching. In the wild, the postlarvae then migrate into estuaries, which are rich in nutrients and low in salinity. There they grow and eventually migrate back into open waters when they mature. Adult shrimp are benthic animals living primarily on the sea bottom.

Distinction from prawns

Biological

Saron neglectus are hiding between the brances of the coral in Kona

Biologists distinguish the true shrimp from the true prawn because of the differences in their gill structures. The gill structure is lamellar in shrimp but branching in prawns. The easiest practical way to separate true shrimps from true prawns is to examine their second abdominal segments. The second segment of a shrimp overlaps both the first and the third segment, while the second segment of a prawn overlaps only the third segment.

Commercial and culinary

While in biological terms shrimps and prawns belong to a different suborders of Decapoda, they are very similar in appearance. In commercial farming and fisheries the terms shrimp and prawn are often used interchangeably. In European countries, particularly the United Kingdom, the word “prawns” is more commonly on menus than the term “shrimp”, which is used more often in North America. The term “prawn” is also loosely used to describe any large shrimp, especially those that come 15 (or fewer) to the pound (also called “king prawns”, but also “jumbo shrimp”). Australia and other Commonwealth countries as well as South Africa follow this European/British use to an even greater extent, using the word “prawn” almost exclusively. The Australian Paul Hogan’s use of the phrase “I'll slip an extra shrimp on the barbie for you” in an American television advertisement was intended to make what he was saying easier for his American audience to understand, and was thus a deliberate distortion of what an Australian would typically say.

In Britain very small crustaceans with a brownish shell, about 1cm long or smaller when shelled, are called shrimp, while anything larger is usually a prawn. Shrimps are sometimes added to dishes not based mainly on them, and used to make potted shrimp.

Commercial fishing

Double-rigged shrimp trawler hauling in the nets

Shrimp bycatch

Main article: Shrimp fishery

Common commercial methods for catching shrimp and prawns include otter trawls, cast nets, seines, shrimp baiting and dip netting. Trawling involves the use of a system of nets. In some parts of the Pacific Northwest, fishing with baited traps is also common.

The following table shows the yearly weight of shrimp and prawns captured globally in millions of tonnes.

Production	1999	2000	2001	2002	2003	2004	2005
Million tonnes	3.03	3.09	2.96	2.97	3.55	3.54	3.42

The highest rates of incidental catch of non-target species is associated with shrimp trawling. In 1997, the FAO documented the estimated bycatch and discard levels from shrimp fisheries around the world. They found discard rates as high as 20 pounds for every pound of shrimp, with a world average of 5.7 pounds for every pound of shrimp.

Worldwide, shrimp trawl fisheries generate about two percent of the world’s catch of fish in weight, but result in more than one third of the global bycatch total.

Trawl nets in general, and shrimp trawls in particular, have been identified as sources of mortality for species of finfish and cetaceans. Bycatch is often discarded dead or dying by the time it is returned to the sea, and may alter food web dynamics in discarded regions.

Sea turtles, already critically endangered, have been killed in large numbers in shrimp trawl nets. For example, estimates indicate that thousands of Kemp's Ridley, loggerhead, green and leatherback sea turtles are caught in shrimp trawl fisheries in the Gulf of Mexico and US Atlantic annually

Concerns about bycatch have led fishermen and scientists to develop devices they can put on their nets to reduce unwanted catch. The "bycatch reduction device" (BRD) and the Nordmore grate are net modifications that help fish escape from shrimp nets. All US shrimp trawlers—and all foreign fleets selling shrimp in the US—are supposed to outfit their nets with trap-door turtle excluder devices (TEDs) to let sea turtles escape. However, not every nation enforces TED use with equal vigor.

Farming

Tanks in a shrimp hatchery.

Main articles: Shrimp farm and Freshwater prawn farm

A shrimp farm is an aquaculture business for the cultivation of marine shrimp or prawnsTemplate:Fn for human consumption. Commercial shrimp farming began in the 1970s, and production grew steeply, particularly to match the market demands of the U.S., Japan and Western Europe. The total global production of farmed shrimp reached more than 1.6 million tonnes in 2003, representing a value of nearly 9,000 million U.S. dollars. About 75% of farmed shrimp is produced in Asia, in particular in China and Thailand. The other 25% is produced mainly in Latin America, where Brazil is the largest producer. The largest exporting nation is Thailand.

Marketing

Main article: Shrimp marketing

Shrimp are marketed and commercialized with several issues in mind. Most shrimp are sold frozen and marketed based on their categorization of presentation, grading, colour, and uniformity.

Shrimp as food

As with other seafood, shrimp is high in calcium, Iodine and protein but low in food energy. A shrimp-based meal is also a significant source of cholesterol, from 122 mg to 251 mg per 100 g of shrimp, depending on the method of preparation. Shrimp consumption, however, is considered healthy for the circulatory system because the lack of significant levels of saturated fat in shrimp mean that the high cholesterol content in shrimp actually improves the ratio of LDL to HDL cholesterol and lowers triglycerides.

Shrimp and other shellfish are among the most common food allergens. They are not kosher and thus are forbidden in Jewish cuisine.

A steamed tail-on shrimp

Preparation

Fried floured shrimp

Preparing shrimp for consumption usually involves removing the head, shell, tail, and "sand vein".

To deshell a shrimp, the tail is held while gently removing the shell around the body. The tail can be detached completely at this point, or left attached for presentation purposes.

Removing the "vein" (a euphemism for the digestive tract) can be referred to as "deveining", though in fact shrimp do not have any real veins; they have an open circulatory system. The "vein" can be removed by making a shallow cut lengthwise down the outer curve of the shrimp's body, allowing the dark ribbon-like digestive tract to be removed with a pointed utensil. Alternatively, if the tail has been detached, the vein can be pinched at the tail end and pulled out completely with the fingers. The shrimp is then rinsed under cold running water.

Shrimp and prawns are versatile ingredients, and are often used as an accompaniment to fried rice. Common methods of preparation include baking, boiling, and frying.

Recipes using shrimp form part of the cuisine of many cultures. Strictly speaking, dishes containing scampi should be made from the Norway lobster, a shrimp-like crustacean more closely related to the lobster than shrimp, but in some places it is quite common for large shrimp to be used instead.

Wet shrimp is commonly used as a flavoring and as a soup base in Asian cuisines (such as Thai tom yum goong) while fried shrimp is popular in North America. In Europe, shrimp is very popular, forming a necessary ingredient in Spanish paella de marisco, French bouillabaisse, Italian cacciucco, Portuguese caldeirada and many other seafood dishes. Shrimp curry is very popular in South Asia and Southeast Asia. Shrimp are also found in Latin and Caribbean dishes such as enchiladas and coconut shrimp. Other recipes include jambalaya, okonomiyaki, poon choi and bagoong.

Shrimp in aquaria

Pandalus borealis

Several types of shrimp are kept in home aquaria. Some are purely ornamental, while others are useful in controlling algae and removing debris. Freshwater shrimp commonly available for aquaria include the Japanese marsh shrimp (Caridina multidentata, also called "Amano shrimp," as their use in aquaria was pioneered by Takashi Amano), cherry shrimp (Neocaridina heteropoda), and ghost or glass shrimp (Palaemonetes spp.). Popular saltwater shrimp include the cleaner shrimp Lysmata amboinensis, the fire shrimp (Lysmata debelius) and the harlequin shrimp (Hymenocera picta).

See also

• Crangon crangon -- the common brown shrimp or prawn (B.E.) much consumed in Europe
• Shrimp baiting
• Krill
• Dried shrimp
• Snapping shrimp
• The Shrimp Girl by William Hogarth

References

• Epperly, S; Avens, L; Garrison, L; Henwood, T; Hoggard, W; Mitchell, J; Nance, J; Poffenberger, J; Sasso, C; Scott-Denton, E and Young, C (2002) Analysis of Sea Turtle Bycatch in the Commercial Shrimp Fisheries of Southeast US Waters and the Gulf of Mexico. NOAA Technical Memorandum NMFS-SEFSC-490.
• Morgan, LE and Chuenpagdee, R (2003) Shifting Gears. Addressing the Collateral Impacts of Fishing Methods in U.S. Waters.
• SAFMC (1998) Final Habitat Plan for the South Atlantic Region Essential Fish Habitat Requirements for Fishery. Management Plans of the South Atlantic Fishery Management Council. The Shrimp Fishery Management Plan (FMP), the Red Drum FMP, the Snapper Grouper FMP, the Coastal Migratory Pelagics FMP, the Golden Crab FMP, the Spiny Lobster FMP, the Coral, Coral Reefs, and Live/Hard Bottom Habitat FMP, the Sargassum Habitat FMP, and the Calico Scallop FMP.

External links

• Template:Dmoz
• Template:Dmoz
• Charles and Raabe, Linda (2008) The Caridean shrimp: Illustrations and Glossary
• Template:Dmoz
• How to Clean Shrimp
• Freshwater aquarium invertebrates, crustacean, pet shrimp, crayfish, crabs forum
• FAO: Shrimp otter trawling