SEX REVERSAL IN FISH TO BOOST PRODUCTIVITY.

University pioneers sex reversal in fish to boost dwindling stocks in kenya. Fish is one of Kenya’s favorite delicacies and also a rich source of protein. However, most consumers of the popular tilapia fish are not aware that the meal on their plate is mostly from a male fish. According to fish scientists, male tilapia are fast maturing, rich in flesh and therefore ideal for market purposes once they attain a weight of between 250 to 400 grammes. For optimum exploitation of the sector, the experts say sex reversal can be done to ensure mass production of the popular white meat. The University of Eldoret (UOE) is currently conducting sex reversals on 20,000 fingerlings following the recent opening of a multipurpose hatchery. The hatchery has the potential to conduct sex reversal on 500,000 fingerlings. The university says, this will boost the production and supply of fingerlings across the North Rift region. With the advent of counties, which have been promoting diversification of agriculture over the last four years, residents of the North Rift are taking up fish farming. Besides, most households are shifting from red meat to fish, which they believe is rich in nutrients and also medicinal. According to Josiah Ani, the fish farm manager at the University of Eldoret, the institution has begun sex reversal on fingerlings using a hormone known as Methyl Testosterone which changes the female hormone to male. “Male fish are highly marketable due to their fast growth. The male fish can achieve the market size faster than the female, which consumes a lot of food to help it in reproduction and development of eggs,according to Ani. Before the transformation is done, brooders fed on protein have to be introduced into a fertilized pond. “The brood should be introduced into the pond in a specific ratio, generally two against one.A female tilapia is checked for fertilized eggs before it is transferred to another tank where it pours outs her eggs. The eggs are then taken to an incubator (container) full of water that circulates through pipes and has a temperature of approximately 24-28 degrees. Here, the eggs are hatched into fingerlings. “When they are hatched, the fingerlings have food attached to their body commonly referred to as yolk sacs. For three days to one week, the fingerlings will derive their food from these yolk sacs. When the yolk is fully absorbed, the fingerlings will become active as they seek food. This is the most ideal moment to conduct the sex reversal. The process, according to Ani, involves the use of methyl testosterone, a hormone, mixed with stock solution (dry matter which is food for the fish and contains high protein) and fed to the fish for 21 to 28 days. Feeding is done four to six times a day. It is mainly conducted during the day because tilapia, unlike catfish, is not photophobic and prefers light when feeding. “Fish is still the safest animal for protein and highly recommendable for both the young and the old. We must strive to increase its numbers as well as conduct sex reversals to ensure more males in the market,” he explained. Read more at: http://www.standardmedia.co.ke/business/article/2000198393/university-pioneers-sex-reversal-in-fish-to-boost-dwindling-stocks?articleID=2000198393&story_title=university-pioneers-sex-reversal-in-fish-to-boost-dwindling-stocks&pageNo=2