The hatchery that gave its prawns away

06 November 2026

Part 2 of 17 · A history of the giant freshwater prawn

Freshwater prawn farming across the Western Hemisphere descends, almost entirely, from thirty-six prawns.[1]

They arrived from Malaysia in 1965 and 1966 at the Anuenue Fisheries Research Center in Honolulu, where Takuji Fujimura and his team set about turning Shao-Wen Ling’s tank result into a production line. By 1972 they had worked out how to rear postlarvae on a commercial scale, and published the method.[2][3]

Then they gave the prawns away. From 1965 onwards, a government hatchery handed out postlarvae free to farmers to stock their ponds.[2] But the stock travelled far beyond Hawaiian ponds. Successful pond trials in Hawaii were followed by attempts at commercial farming in many other places, Australia among them.[2] Guam took its prawns from Hawaii in 1974;[4] a university in Brazil imported postlarvae straight from Anuenue in 1977;[5] and from the 1970s, breeding stock from Hawaii and Thailand began to reach countries where the species is not native.[3]

Taiwan’s industry began with even fewer: a single pair. The species had turned up now and then in the rivers of southern Taiwan, but farming there grew from two adults imported from Thailand in 1970.[2] Taiwan went on to become one of the pioneers of modern prawn farming.[3]

Thirty-six is a small family to found a hemisphere on, and two is smaller. Decades later, when geneticists compared farmed and wild prawns, many of the farmed populations carried less genetic variety than wild prawns from Myanmar.[1] The generosity that spread the prawn so quickly also spread it from very few parents.

For several years, Hawaii was the place the aquaculture press associated with freshwater prawns, and in 1978 it was predicted that Hawaiian farms would be producing 1,000 tonnes a year by 1981. They produced 118.[2] Thailand, where people had long eaten the prawn, had farmed 3 tonnes in 1976. By 1987 it was farming an estimated 15,000.[2]

Sources

1. University of Southern Mississippi, microsatellite study of wild and cultured giant freshwater prawn: Western Hemisphere culture derived primarily, if not entirely, from 36 prawns introduced to Hawaii from Malaysia in 1965 and 1966; reduced genetic diversity in many cultured populations. aquila.usm.edu
2. New, M. B. (1987), Freshwater prawns: status of global aquaculture. FAO. Anuenue and Fujimura; free postlarvae from 1965; early commercial attempts including Australia; Taiwan’s two adults from Thailand, 1970 (citing Chen, 1976); the 1978 forecast of 1,000 t a year by 1981 and the 118 t produced; Thailand 3 t (1976) to an estimated 15,000 t (1987). fao.org
3. FAO (2009), Cultured aquatic species fact sheet: Macrobrachium rosenbergii. Mass rearing for commercial-scale hatchery production by 1972; broodstock from Hawaii and Thailand introduced worldwide from the 1970s; Taiwan and Thailand as pioneers. fao.org
4. Smithsonian Environmental Research Center, NEMESIS species summary: Macrobrachium rosenbergii imported to Guam from Hawaii, 1974. invasions.si.edu
5. Genetics and Molecular Biology (SciELO), on the introduction of the giant river prawn to Brazil: postlarvae imported from the Anuenue centre, 1977. scielo.br

Part 2 of 17 · A history of the giant freshwater prawn · Previous: Part 1, The larvae that needed the sea · Next: Part 3, Science in Hawaii, an industry in Thailand · SHRMP.bio’s strategy behind it: shrmp.bio/strategy.html