Giant River Prawn Achieves Excellent Prices in Seafood Markets

The giant river prawn (Macrobrachium rosenbergii) achieves excellent prices in seafood markets across Asia and the global export markets.

Specialist online marketing together with Hi-Tech farming methods and the recent development of monosex broodstock could well make it as popular as vannamei shrimps.

In the earlier years of shrimp/prawn farming the whiteleg shrimp (Litopenaeus vannamei) and tiger prawns (Penaeus monodon), created billion dollar industries, they established a substantial part of the aquaculturists industry.

One of the first GRP aquaculture breakthrough came in 1961, when the Food and Agriculture Organization (FAO) discovered that Macrobrachium rosenbergii or GRP was able to survive in brackish water for more than five days.

The discovery that its larvae needed brine to survive for more than five days was a vital breakthrough for the aquaculture industry.

But to date most seafood consumers have not recognised this excellent species which is the largest member of Macrobrachium of shrimps/prawns group. Other species include crabs, lobsters, crayfish and other familiar critters seafood which consumers love.

The 240 or so Macrobrachium species are found in tropical and subtropical waters, they can be found in lakes, rivers, ponds and streams across most continents. Most species are amphidromous and their lifetime require to live in both fresh and seawater. Eggs wash downstream to the sea, then develop into juveniles. They then travel as far as 100km upstream to breed. This is the beginning of the next generation.

The GRP grows larger than any other shrimps or prawns of the Macrobrachium species. Females grow to 25cm and the larger males grow up to 32cm, excluding their long claws which can extend their length to 60cm.

One of the difficulties of farming GRPs successfully is that dominant males are especially vicious towards each other and cannot be reared as intensively as marine shrimps.

Males are divided into three sizes they have claws of different colours and sizes: The small males (SM) have short translucent claws; mid-sized orange\aw claws (OC) have large yellow-orange claws as long as their bodies; while large blue claws (BC) have bright blue claws twice as long as their bodies. Blue claws dominate orange claws, while small males sit at the bottom of the heap. The presence of higher-caste males inhibits the growth and development of both male and female GRPs.

Wild GRPs live in shallow, muddy ponds, lakes and rivers which have good vegetation. They are able to crawl onto land and climb up relatively vertical surfaces like waterfalls, they move around at night – and spend their days half-buried in mud. After night fall, they forage and hunt for worms, crustaceans, molluscs and fish. People have caught and eaten GRPs for thousands of years in Asia but modern farming began just a half-century ago.

The new giant river prawn is now being successfully farmed – and it will soon be available super markets, restaurants and hotels around the world.

Photo by C.Luckhaup