Frequently Asked Questions

What is UdangGalah and where are they being reared ?


The scientific name for udanggalah is Macrobrachiumrosenbergii and it is one of Malaysia indigenous species of fresh water prawn. Malaysia is the first country to discover the method for freshwater prawn farming back in the 1960s. Malaysia produces only a dismal 400 metric tons yearly while China is the world’s largest producer and farms 400,000 metric tons each year. Vietnam, Thailand, Taiwan and Indonesia too produce a sizeable number. The industry globally is worth US$7bil (RM29.39bil).




Is it easy to grow UdangGalah and how long it take to grow them to marketable size?


Under conventional method, most farmers take their post larvae or juvenile from hatcheries that take female brood stock from the rivers which will produce mix population of male and female every batch. Ratio of the mix population usually is about 70% female and 30% male. With mixed prawns, the size varies between the male and female prawn, with the males being bigger.

When there are male and female prawns, the males have to fight with other males to get the female to mate. When they fight, some will die. Energy is diverted and productivity goes down, which means feeding and operational costs goes up. It takes 150 to 180 days to harvest these mixed sex prawns. Due to mating some female will not be growing as their energy are dispersed into having eggs which cannot hatch in fresh water. Farmers will find many differing sizes in the pond and have to do selective harvesting which will require more labor and cost. During such harvesting, remaining prawns will be stressed and cause more mortality.




What is the suitable water and temperature for rearing udanggalah?


Udanggalah has been found to survive between 0 to 20 ppt salinity. It is recommended that grow out pond salinity should not be more than 8 ppt as the growth rate greatly reduced after that salinity range and this varies between strains and geographical variation. Udang-galah has been found to survive between 23 degree to 35 degree Celsius but recommended optimum growth rate is between 26 degree to 32 degree Celsius.




Can we grow udanggalah in concrete pond or fiber tanks?


Udanggalah can be grown in almost every type of containment but it is recommended to be grown in mud ponds which has more natural food like algae, plankton, zoo plankton, insects’ larvae and other oganisms. Pellet feed are supplements in mud ponds. Growing in suitable mud ponds with the right probiotics and ingredients will produce required organic additional food and give better growth rate.




What is the challenges and problems associated with growing udanggalah ?


Aside from securing good quality prawn fry, the major challenges aside from normal water quality, farm management and operation husbandry, the major problem is the four and two legged predators. Farmers must keep up with latest method to prevent predations and theft.




What are the diseases associated with growing udanggalah?


MacrobrachiumNodavirus (MrNV) but usually with disease free broodstock at hatchery level, the disease occurrence at farm level will not arise.




How do we overcome the challenges in growing udanggalah ?


As in any aquaculture sector, proper management and operation husbandry is crucial to ensure good survival and production. It would be good if farmers work with reputable hatchery and nursery that provide quality post larvae or juvenile as well as provide good advice on how to improve survival rate.




Why is monosex technology and how do it help in growing udanggalah ?


GK Aqua uses an unique biotech method to produce all male prawns post larvae and juvenile for breeding. The monosex ones only takes 90 days to grow to marketable size compared conventional mixed population which take up to 150 days.

By farming only all-male baby prawn larvae, making it an all-male affair which is like all male prisoners having nothing to do but to eat and built their bodies in an all-male prison. The results are overwhelming. There is no fighting over female for mating. The mono sex prawn are three times in size and going from 4gm to 80gm within the next 90 days. “Our pilot study shows that we can get 130% more yield this way compared to the conventional (mixed sex) prawn farming.”

A one-acre piece of land,can produce 1.2 tons of all male prawns every six months. In a worst-case scenario, if a farmer with a two-acre farm is really incompetence and gets only a 30% to 40% survival rate for his all-male prawns and If the farmers husbandry practice is good they can achieve 60-70% survival rate.




What is the best size to harvest and what size is optimum for eating udanggalah ?


There is no best size but marketable size start from 60 to 250 grams. Different size prawn are needed for different sectors ranging from recreational prawn fishing to the food industry. Normally prawns in the market exceeding 300 grams are normally wild caught and to grow it under aquaculture environment will not be economical (time taken could reach 2 years)




How do we procure the all-male post larvae and juvenile udanggalah ?


Please contact Ms Siti Azzah (phone?)





UDANG GALAH