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 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.
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.
Most shrimp mature and breed only in a marine habitat, although there are a small number of freshwater species. 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 marine 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. Most adult shrimp are benthic animals living primarily on the sea floor.
Common shrimp species include rock, pink, royal red brown, white and snapping shrimp. Depending on the species and location, they grow from about 1.2 cm (0.5 in) to 30 cm (12 in) long, and live between one and 6.5 years.
Distinction from prawns:-
Arthropods can be subdivided into several classes, one of which is the Malacostraca.
This class contains about half of the crustaceans. The members of this class have a primitive body plan that can be described as shrimp-like, consisting of a 5-8-7 body plan. They have a small carapace that encloses the head and the thorax, and have a muscular abdomen for swimming. They also have a thin exoskeleton to maintain a light weight. These general characters are common in all members of the class.
The class can be further divided into the decapods, which are even still divided into the dendrobranchiates (prawns) and the carideans (shrimp and snapping shrimp).
The prawns have sequentially overlapping body segments (segment one covers the segment two, segment two covers segment three, etc), chlelate (claw like) first three leg pairs, and have a very basic larval body type.
The shrimps also have overlapping segments, however, in a different pattern (segment two overlaps segments one and three), only the first two leg pairs are chelate, and they have a more complex larval form.
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 the second abdominal segment. 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 different suborders of Decapoda, they are very similar in appearance. In commercial farming and fisheries, the terms shrimp and prawn are often used interchangeably. However, recent aquaculture literature increasingly uses the term “prawn” only for the freshwater forms of palaemonids and “shrimp” for the marine penaeids.
In the United Kingdom, the word “prawn” is more common on menus than “shrimp”; while the opposite is the case 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 (such as “king prawns”, yet sometimes known as “jumbo shrimp”). Australia and other Commonwealth nations follow this British usage to an even greater extent, using the word “prawn” almost exclusively. When Australian comedian Paul Hogan used the phrase, “I’ll slip an extra shrimp on the barbie for you” in an American television advertisement, it 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 are called shrimp, and are used to make potted shrimp. They are also used in dishes where they aren’t the primary ingredient.
For more knowledge You may click & see:->
*List of shrimp and prawn species
*List of freshwater aquarium shrimp
*Crangon crangon – the common brown shrimp or prawn (B.E.) much consumed in Europe
*The Shrimp Girl by William Hogarth
*New Zealand freshwater shrimp
Very Good, Tasty & Healthy 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 means that the high cholesterol content in shrimp actually improves the ratio of LDL to HDL cholesterol and lowers triglycerides.
Some people may have Shrimp Allergy and for them it is always advicible not to eat it at all and he or she should avoid all types of shell food as all shellfish are closely related, and they all include similar allergy-causing proteins called “tropomyosins.” This is especially true of shellfish that are in the same family. (There are two main families of edible shellfish: crustaceans, which include shrimp, lobsters, crabs and crayfish, and mollusks, which include oysters, scallops, clams and mussels.)
Shrimp and other shellfish are among the most common food allergens. They are not kosher and thus are forbidden in Jewish cuisine. However, according to some mazhab, shrimp are halal, and therefore are permissible in Islamic cuisine.
http://en.wikipedia.org/wiki/Shrimp and other different internet sites