A freshwater prawn farm is an aquaculture business designed to raise and produce freshwater prawn or shrimp¹ for human consumption. Freshwater prawn farming shares many characteristics and problems with marine shrimp farming. Unique problems are introduced by the main species' (the Giant River Prawn, Macrobrachium rosenbergii) developmental life cycle.^[New02] Aquaculture is the cultivation of aquatic organisms, such as fish, shellfish, algae and other aquatic plants. ... Superfamilies Panaeoidea Aristeidae Benthesicymidae Penaeidae Sicyoniidae Solenoceridae Sergestoidea Luciferidae Sergestidae Prawns are edible, shrimp-like crustaceans, belonging to the sub-order Dendrobranchiata. ... Superfamilies and families Alpheoidea Alpheidae - snapping shrimps Barbouriidae Hippolytidae Ogyrididae Atyoidea Atyidae Bresilioidea Agostocarididae Alvinocarididae Bresiliidae Disciadidae Mirocarididae Campylonotoidea Bathypalaemonellidae Campylonotoidae Crangonoidea Crangonoidea Glyphocrangonoidea Galatheacaridoidea Galatheacarididae Nematocarcinoidea Eugonatonotidae Nematocarcinidae Rhynchocinetidae Xiphocarididae Oplophoroidea Oplophoridae Palaemonoidea Anchistioididae Desmocarididae Euryrhynchidae Gnathophyllidae Hymenoceridae Kakaducarididae Palaemonidae Typhlocarididae Pandaloidea Pandalidae Thalassocarididae Pasiphaeoidea Pasiphaeidae Physetocaridoidea Physetocarididae Procaridoidea... Shrimp growout pond on a farm in South Korea. ...

The global annual production of freshwater prawns (excluding crayfish and crabs) in 2003 was about 280,000 tonnes, of which China produced some 180,000 tonnes, followed by India and Thailand with some 35,000 tonnes each. China also produced about 370,000 tonnes of Chinese River Crab (Eriocheir sinensis).^[FIGIS] The word crayfish or crawfish can mean:- Sea crayfish, also called spiny lobster. ... Sections Dromiacea Raninoida Heterotremata Thoracotremata The term crab is often applied to several different groups of short (nose to tail) decapods with thick exoskeletons, but only members of the Brachyura are true crabs; other taxa, such as hermit crabs, porcelain crabs, king crabs, and horseshoe crabs are, despite superficial similarities... 2003 is a common year starting on Wednesday of the Gregorian calendar. ...

Species

All farmed freshwater prawns today belong to the genus Macrobrachium. Until 2000, the only species farmed was the Giant River Prawn (Macrobrachium rosenbergii, also known as the Malaysian Prawn). Since then, China has begun farming the Oriental River Prawn (M. nipponense) in large quantities, and India farms a small amount of Monsoon River Prawn (M. malcolmsonii). In 2003, these three species accounted for all farmed freshwater prawns, about two thirds M. rosenbergii and one third M. nipponense. 2005 is a common year starting on Saturday of the Gregorian calendar. ... See genus (mathematics) for the use of the term in mathematics. ... 2000 is a leap year starting on Saturday of the Gregorian calendar. ... 2003 is a common year starting on Wednesday of the Gregorian calendar. ...

There are about 200 species in the genus Macrobrachium. They occur throughout the tropics and subtropics on all continents except Europe.

Biology of Macrobrachium rosenbergii

Giant River Prawns live in turbid freshwater, but their larval stages require brackish water to survive. Males can reach a body size of 32 cm;females grow to 25 cm. In mating, the male deposits spermatophores on the underside of the female's thorax, between the walking legs. The female then extrudes eggs, which pass through the spermatophores. The female carries the fertilized eggs with her until they hatch; the time may vary, but is generally less than three weeks. A large female may lay up to 100,000 eggs. For the village on the Isle of Wight, see Freshwater, Isle of Wight. ... Brackish water is water that is saltier than fresh water, but not as salty as sea water. ... A spermatophore is a capsule or mass created by males of various invertebrate species, containing spermatozoa and transferred in entirety to the female during sex. ...

From these eggs hatch zoeae, the first larval stage of crustaceans. They go through several larval stages before metamorphosing into postlarvae, at which stage they are about 8 mm long and have all the characteristics of adults. This metamorphosis usually takes place about 32 to 35 days after hatching. These postlarvae then migrate back into freshwater. The zoea larva of the blue king crab, Paralithodes platypus The zoea is the first free-swimming larval stage of crustaceans. ... Classes Branchiopoda Cephalocarida Malacostraca Maxillopoda Ostracoda Remipedia The crustaceans (Crustacea) are a large group of arthropods (55,000 species), usually treated as a subphylum. ...

There are three different morphotypes of males. The first stage is called "small male" (SM); this smallest stage has short, nearly translucent claws. If conditions allow, small males grow and metamorphose into "orange claws" (OC), which have large orange claws on their second chelipeds, which may have a length of 0.8 to 1.4 their body size. OC males later may transform into the third and final stage, the "blue claw" (BC) males. These have blue claws, and their second chelipeds may become twice as long as their body.^[Wyn00]

Male M. rosenbergii have a strict hierarchy: the territorial BC males dominate the OCs, which in turn dominate the SMs. The presence of BC males inhibts the growth of SMs and delays the metamorphosis of OCs into BCs; an OC will keep growing until it is larger than the largest BC male in its neighbourhood before transforming. All three male stages are sexually active though, and females who have undergone their pre-mating molt will cooperate with any male to reproduce. BC males protect the female until their shell has hardened, OCs and SMs show no such behavior.

Technology

Giant River Prawns have been farmed using tradinitional 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. 1960 was a leap year starting on Friday (link will take you to calendar). ... This article provides extensive lists of events and significant personalities of the 1970s. ... State nickname: The Aloha State Other U.S. States Capital Honolulu Largest city Honolulu Governor Linda Lingle Official languages Hawaiian and English Area 28,337 km² (43rd)  - Land 16,649 km²  - Water 11,672 km² (41. ...

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). Shrimp growout pond on a farm in South Korea. ...

Due to the aggressive nature of M. rosenbergii and the hierarchy between males, stocking densities are much lower than in penaeid shrimp farms. Intensive farming is not possible due to the increased level of cannibalism, so all farms are either stocked semi-intensively (4 to 20 postlarvae per square metre) or, in extensive farms, at even lower densities (1 to 4/m²). The management of the growout ponds must take into account the growth characteristics of M. rosenbergii: the presence of blue-claw males inhibits the growth of small males, and delays the metamorphosis of OC males into blue-claws. Some farms fish off the largest prawns from the pond using seines to ensure a healthy composition of the pond's population, designed to optimize the yield, even if they employ batch harvesting. The heterogeneous individual growth of M. rosenbergii makes growth control necessary even if a pond is stocked newly, starting from scratch: some animals will grow faster than others and become dominant BCs, shunting the growth of other individuals. Superfamilies and families Alpheoidea Alpheidae - snapping shrimps Barbouriidae Hippolytidae Ogyrididae Atyoidea Atyidae Bresilioidea Agostocarididae Alvinocarididae Bresiliidae Disciadidae Mirocarididae Campylonotoidea Bathypalaemonellidae Campylonotoidae Crangonoidea Crangonoidea Glyphocrangonoidea Galatheacaridoidea Galatheacarididae Nematocarcinoidea Eugonatonotidae Nematocarcinidae Rhynchocinetidae Xiphocarididae Oplophoroidea Oplophoridae Palaemonoidea Anchistioididae Desmocarididae Euryrhynchidae Gnathophyllidae Hymenoceridae Kakaducarididae Palaemonidae Typhlocarididae Pandaloidea Pandalidae Thalassocarididae Pasiphaeoidea Pasiphaeidae Physetocaridoidea Physetocarididae Procaridoidea...

The FAO considers the ecological impact of freshwater prawn farming to be less severe than in shrimp farming. The prawns are cultured at much lower densities, meaning less concentrated waste products and a lesser danger of the ponds becoming breeding places for diseases. The growout ponds do not salinate agricultural land, as do those of inland marine shrimp farms. Freshwater prawn farms do not endanger mangroves, and are better amenable to small-scale businesses run by a family.^[FAO] Headquartered in Rome, Italy, the Food and Agriculture Organization (FAO) of the United Nations programs seek to raise levels of nutrition and standards of living; to improve the production, processing, marketing, and distribution of food and agricultural products; to promote rural development; and, by these means, to eliminate hunger. ... Shrimp growout pond on a farm in South Korea. ... Above and below water view at the edge of the mangal Mangrove are woody trees or shrubs that grow in coastal habitats or mangal (Hogarth, 1999), for which the term mangrove swamp also would apply. ...

Economics

The global annual production of freshwater prawns in 2003 was about 280,000 tonnes, of which China produced some 180,000 tonnes, followed by India and Thailand with some 35,000 tonnes each. Other major producer countries are Taiwan, Bangladesh, and Vietnam. In the United States, there are only a few hundred small farms for M. rosenbergii with an overall production of just about 50 tonnes in 2003.^[FIGIS] The U.S. is, though, the largest producer of farmed crayfish. In 2003, U.S. farms produced 33,500 tonnes of Red Swamp Crawfish (Procambarus clarkii), a crayfish species native to Louisiana. 2003 is a common year starting on Wednesday of the Gregorian calendar. ... The word crayfish or crawfish can mean:- Sea crayfish, also called spiny lobster. ... 2003 is a common year starting on Wednesday of the Gregorian calendar. ... State nickname: Pelican State Other U.S. States Capital Baton Rouge Largest city New Orleans Governor Kathleen Blanco Official languages None; English and French de facto Area 134,382 km² (31st)  - Land 112,927 km²  - Water 21,455 km² (16%) Population (2000)  - Population 4,468,976 (22nd)  - Density 39. ...

See also

• The technologies used in freshwater prawn farming, but also the ecological problems associated with this industry, are basically the same as for marine shrimp farming and are discussed in yonder article.

Shrimp growout pond on a farm in South Korea. ...

Footnotes

Note 1: The terminology is sometimes confusing as the distinction between "shrimp" and "prawn" is sometimes blurred. Recent aquaculture literature increasingly uses the term "prawn" only for the freshwater forms of Palaemonids and "shrimp" for the marine penaeids.^[IAA01] Superfamilies and families Alpheoidea Alpheidae - snapping shrimps Barbouriidae Hippolytidae Ogyrididae Atyoidea Atyidae Bresilioidea Agostocarididae Alvinocarididae Bresiliidae Disciadidae Mirocarididae Campylonotoidea Bathypalaemonellidae Campylonotoidae Crangonoidea Crangonoidea Glyphocrangonoidea Galatheacaridoidea Galatheacarididae Nematocarcinoidea Eugonatonotidae Nematocarcinidae Rhynchocinetidae Xiphocarididae Oplophoroidea Oplophoridae Palaemonoidea Anchistioididae Desmocarididae Euryrhynchidae Gnathophyllidae Hymenoceridae Kakaducarididae Palaemonidae Typhlocarididae Pandaloidea Pandalidae Thalassocarididae Pasiphaeoidea Pasiphaeidae Physetocaridoidea Physetocarididae Procaridoidea... Superfamilies Panaeoidea Aristeidae Benthesicymidae Penaeidae Sicyoniidae Solenoceridae Sergestoidea Luciferidae Sergestidae Prawns are edible, shrimp-like crustaceans, belonging to the sub-order Dendrobranchiata. ...

References

The main reference for this article was a comprehensive farming manual of the FAO: Headquartered in Rome, Italy, the Food and Agriculture Organization (FAO) of the United Nations programs seek to raise levels of nutrition and standards of living; to improve the production, processing, marketing, and distribution of food and agricultural products; to promote rural development; and, by these means, to eliminate hunger. ...

• New02: New, M. B.: Farming Freshwater Prawns; FAO Fisheries Technical Paper 428, 2002. ISSN 0429-9345.

Other references:

• FAO: FAO: Cultured Species Fact Sheet M. rosenbergii; accessed June 30, 2005. Has images.
• FIGIS: Data extracted from the FAO Fisheries Global Aquaculture Production Database for freshwater crustaceans. The most recent data sets are for 2003 and sometimes contain estimates. Accessed June 28, 2005.
• IAA01: Indian Aquaculture Authority: Shrimp Aquaculture and the Environment - An Environment Impact Assessment Report, ch. 2; IAA report, April 2001.
• Wyn00: Wynne, F.: Grow-out Culture of Freshwater Prawns in Kentucky, 2000. Last accessed July 4, 2005.