(MENAFN - Muscat Daily) To increase the production of farm-raised tilapia, the Ministry of Agriculture and Fisheries (MoAF) has turned to sex reversal in the fish.
Super males are being produced through genetic engineering so that when they are bred with females, all the offsprings are males.
The reason for working on male tilapia population is that males grow faster, are larger and fleshier and hence, more in demand among consumers. ''Moreover, males need less feed unlike female tilapias. This means less production costs,'' said Dr Fahad S Ibrahim, director of the Aquaculture Centre under MoAF.
''Our aim is to generate male tilapias for consumption without the use of any harmful substances. That is why we went for a genetic engineering technique for sex reversal in the fish or in other words, to get transsexual fish. The end result is the supermale (YY chromosomes).''
Breeding between a normal male (XY chromosome) and female (XX chromosome) tilapia doesn't essentially lead to only male fry. ''Half of the fry could be females. The male fry are given a particular diet for some days which makes them phenotypic female (which look like females but are genetically males).
''Since these phenotypic females are capable of producing eggs, they are mated with normal males to produce a batch of fry containing 75 per cent males, thus diminishing the number of female offspring. Males from this batch when mated with female tilapias produce only male offsprings,'' he said.
Funded by the Agriculture and Fisheries Development Fund (AFDF) under MoAF, the Aquaculture Centre has started developing a local hatchery for tilapia in collaboration with farmers.
Citing reasons for concentrating on male tilapias, Dr Ibrahim said, ''Since fresh water is scarce in the country, the aim is to make best use of it for food production. The reason for going for tilapia farming is because this fish can tolerate adverse environmental conditions and has the ability to survive low oxygen levels and salinity concentration.''
He said the centre is experimenting on setting up ten model tilapia farms, each expected to produce 36 tonnes fish per year. ''We are hopeful the model farms will help farmers and make the best use of water. If successful, we will replicate them at 50 to 60 pla
