Prawns

In commercial farming and fishery, the terms prawn and shrimp are generally used interchangeably. In European countries, particularly the United Kingdom, the word “prawns” is far more common on menus than the term “shrimp”, which is generally only used 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”).

In various forms of English, the name “prawn” is often applied to shrimp as well, generally the larger species, such as Leander serratus. In the United States, according to the 1911 Encyclopædia Britannica, the word “prawn” usually indicates a freshwater shrimp or prawn. In Middle English, the word “prawn” is recorded as prayne or prane; no cognate form can be found in any other language. It has often been connected to the Latin perna, a ham-shaped shellfish, but this is due to an old scholarly error that connected perna and parnocchie with prawne-fishes or shrimps. In fact, the Old Italian perna and pernocchia meant a shellfish that yielded nacre, or mother-of-pearl.

A freshwater prawn farm is an aquaculture business designed to raise and produce freshwater prawn or shrimp for human consumption. Freshwater prawn farming shares many characteristics with, and many of the same problems as, marine shrimp farming. Unique problems are introduced by the developmental life cycle of the main species (the giant river prawn, Macrobrachium rosenbergii). The global annual production of freshwater prawns (excluding crayfish and crabs) in 2003 was about 280,000 tons, of which China produced some 180,000 tons, followed by India and Thailand with some 35,000 tons each. Additionally, China produced about 370,000 tons of Chinese river crab.

Giant River Prawns have been farmed using traditional methods in south-east Asia for a long time. First experiments with artificial breeding cultures of M. rosenbergii were done in the early 1960s in Malaysia, where it was discovered that the larvae needed brackish water for survival. Industrial-scale rearing processes were perfected in the early 1970s in Hawaii, and spread then first to Taiwan and Thailand and then to other countries. The technologies used in freshwater prawn farming are basically the same as in marine shrimp farming. hatcheries produce postlarvae, which then are grown and acclimated in nurseries before being transferred into growout ponds, where the prawns are then fed and grown until they reach marketable size. Harvesting is done by either draining the pond and collecting the animals ("batch" harvesting) or by fishing the prawns out of the pond using nets (continuous operation).