Penaeus monodon, often called the giant tiger prawn, is an important species for aquaculture.
Prawn is a common name, used particularly in the United Kingdom, Ireland and Commonwealth nations, for large swimming crustaceans or shrimp, especially those with commercial significance in the seafood industry. Shrimp that fall in this category often belong to the suborder Dendrobranchiata. In North America, the term is used less frequently, typically for freshwater shrimp.
In the United Kingdom prawn is more common on menus than shrimp, while the opposite is the case in the United States. The term prawn also loosely describes any large shrimp, especially those that come 15 (or fewer) to the pound (such as king prawns or jumbo shrimp).
Although prawns are sometimes defined as large freshwater shrimp, there are many counter-examples; the "bigclaw river shrimp", Macrobrachium carcinus, is a large caridean shrimp that lives in fresh water, and is rarely referred to as a "prawn".
According to the crustacean taxonomist Tin-Yam Chan, "The terms shrimp and prawn have no definite reference to any known taxonomic groups. Although the term shrimp is sometimes applied to smaller species, while prawn is more often used for larger forms, there is no clear distinction between both terms and their usage is often confused or even reverse in different countries or regions."
A lot of confusion surrounds the scope of the term shrimp. Part of the confusion originates with the association of smallness. That creates problems with shrimp-like species that are not small. The expression "jumbo shrimp" can be viewed as an oxymoron, a problem that does not exist with the commercial designation "jumbo prawns".
The term shrimp originated around the 14th century with the Middle Englishshrimpe, akin to the Middle Low Germanschrempen, and meaning to contract or wrinkle; and the Old Norseskorpna, meaning to shrivel up. It is not clear where the term prawn originated, but early forms of the word surfaced in England in the early 15th century as prayne, praine and prane. According to the linguist Anatoly Liberman it is unclear how shrimp, in English, came to be associated with small. "No Germanic language associates the shrimp with its size... The same holds for Romance... it remains unclear in what circumstances the name was applied to the crustacean."
Shrimps and prawns
It is impossible to give a short definition of either name, as in different regions these terms are used for different animals or animal groups, and even within a single region the usage is not consistent... All in all the situation is quite confused, and nowhere a sharp distinction seems to be made between shrimps and prawns. In general one can say that the larger... species that are commercially most attractive are called shrimps in America, and prawns in most of the rest of the English-speaking world. The word shrimp being used almost everywhere for the... other small forms, but many exceptions occur here.
The terms shrimp and prawn originated in Great Britain. Shrimp is applied to smaller species, particularly species that are dorsoventrally depressed (wider than deep) with a shorter rostrum. It is the only term used for species in the family Crangonidae, such as the common shrimp or brown shrimp, Crangon crangon. Prawn is never applied to very small species. It is applied to most of the larger forms, particularly species that are laterally compressed (deeper than wide) and have a long rostrum. However, the terms are not used consistently. For example, some authors refer to Pandalus montagui as an Aesop shrimp while others refer to it as an Aesop prawn.
Commonwealth countries, and Ireland, tend to follow British usage. There are some exceptions in Australia where some authors refer to small species of Palaemonidae as prawns and call Alpheidae pistol shrimp. Other Australian authors have given the name banded coral shrimp to the prawn-like Stenopus hispidus and listed "the Processidae and Atyidae as shrimps, the Hippolytidae, Alpheidae, Pandalidae and Campylonotoidea as prawns". New Zealand broadly follows British usage. A rule of thumb given by some New Zealand authors states; "In common usage, shrimp are small, some three inches or less in length, taken for food by netting, usually from shallow water. Prawn are larger, up to twelve inches long, taken by trapping and trawling." South Africa and the former British colonies in Asia also seem to generally follow British usage.
In the United States the term shrimp is used for almost all species. Prawn is less commonly used. Shrimp is the more general term, both in Britain and in North America, but most particularly in the United States. In the United States, the term prawn applies especially to larger shrimps and those that live in freshwater.