PORT DICKSON: The giant river prawn or its scientific name macrobrachium rosenbergii, is a species of the palaemonid freshwater prawn, which has high domestic and export potential.
Realising this, a giant prawnfarm owner here, Giva Kuppusamy (pix) , 36, took the initiative to apply biotechnological technique for the production of monosex prawn populations, thus ensuring there is continuous supply of broodstock.
Photo: GK Aqua
“I used to work at a 100-acre giant prawn farm in Pahang in 2009 and I found that the main problem was maintaining the broodstock and that most projects require domestication of parent stocks and a lot of money was invested in research but there were no results.
"As such the giant prawn farming industry failed to develop, people were opening aquaculture ponds but they couldn’t get supply of shrimp seeds, so in 2016 together with five partners, I started GK Aqua to begin the technique of all-male monosex culture of giant prawns,"he told Bernama news agency.
Giva, a University of Malaya biotechnology graduate said, the male giant prawn is ‘paired’ and bred using micro-surgical technique on the androgenic gland and this would transform the male into a fully-functioning neo-female.
According to Giva, the normal male prawns are injected with the enzyme ribonucleic acid interference (RNAi) to inhibit male development and transform them into neo-females which genetically are still males but are able to produce eggs.
When matured, he said the neo-female prawn would be 'paired' with the normal male parent for the mating process and almost all the seeds produced from the neo-female are males.
He said through this prawn production technique, its capacity could be increased and it only requires four months for the prawns to be fully developed while the conventional method would usually take nine months.
"In this way too, farming operation costs can be reduced and the size of the prawn produced is three times the size of the ordinary giant prawn and based on clients’ records, through this technique, from 100,000 seeds they could get returns of around 1,200 to 1,500 tonnes of giant prawns,” he said.
Giva who hails from Perak but has been living in Negeri Sembilan for a long time, said he has received approval for the monosex culture technique from the Biosafety Department and the Genetic Modification Advisory Committee.
Photo: GK Aqua
Elaborating, Giva said the project started in 2016 on a one- acre lease land in Lenggeng here, but it was moved to a farm in Bukit Pelanduk last year, after facing difficulties in obtaining nearby water source.
Giva said they were able to obtain over a million life seeds at the six-acre leased farm and earn a return of around RM100,000 a month, but following the Movement Control Order (MCO), the demand for the seeds had declined.
"At GK Aqua, the parent giant prawns are bred for 38 days before they are sold to customers who are usually fish pond business operators, so when the MCO was enforced and people are not allowed to go fishing, we were also affected,” said Giva who also has a master's degree in ecocultural sustainability from Scotland.
He said the Negeri Sembilan Fisheries Department (JPNS) often visits the farm to monitor the situation and get their supply of adult prawn broodstock.
Giva said that great care is needed in giant prawn farming as they must be monitored every hour, especially the water temperature and mineral content in the pond, adding that the water must be replaced every 15 days.
In addition, Giva said he was also planning to bring giant prawn farming or ugady to padi fields in the state, as an effort towards chemical-free crop production and help farmers to increase their income.
Meanwhile, JPNS director Halimi Abu Hanip said the effort by GK Aqua in monosex culture is seen as an industry 4.0 game changer which could help Negeri Sembilan in its aspiration to be the nation’s freshwater prawn farming valley.
He said the giant prawn species can be sold at over RM70 per kilogramme and they are popular for recreational or sport fishing purposes, especially for fishing ponds.
On challenges faced by the livestock industry, he said most prawn breeders depend on wild adult prawns and the seed survival rate is also relatively low.
In addition he said, the Covid-19 pandemic which had forced fishing ponds to close had also left the prawns unsold.
On JPNS’ efforts to ensure the prawn species will continue to be maintained, Halimi said the department is actively releasing the giant prawn seeds into rivers for the purpose of conserving its population in their natural habitat, including in Sungai Rembau-Linggi and Sungai Muar in Gemas.
"In terms of aquaculture, the department provides support, technical advisory services and input to assist farmers so that giant prawn farming can be expanded in Negeri Sembilan," he said.
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