Scientists are giving “sex changes” to prawns so farmers can reap the economic benefits of producing faster growing and meatier males. Just a year after the procedure made it possible, Asian farmers have fully embraced this offbeat method to increase profits.

The procedure requires two main stages in order to create an all-male mob of giant freshwater prawns (Macrobrachium rosenbergii). It all starts with the androgenic gland, an organ unique to crustaceans that produces a hormone that regulates sexual differentiation and the production of male reproductive organs. The hormone is suppressed by injecting a molecule that silences the expression of the gene that codes for its production. This cutting-edge technique is called temporal gene silencing.

This procedure allows scientists to create “neo-females,” essentially prawns that are genetically male but with all the lady prawn bits needed to reproduce. These neo-females are then bred with normal males, which makes all of their offspring male.

The project was developed by a team of scientists at the Ben-Gurion University of the Negev in Israel. The scientific research was completed and published last year, however Reuters has reported that this new technique is taking hold in the Asian food industry.

Professor Amir Sagi, who heads the research group, said workers can inject around 2,000 prawns a day by hand in Israel, where they are then shipped out to Vietnam, China and India. The prawns can release thousands of eggs each, so over several cycles, millions of male prawns can be produced – although only the injected generation will be affected from the gene silencing. It’s estimated that the development could help increase a farmer’s income by 60%.

“The advantage of this technology is that with using all male with that technology is that we do not have to use any chemicals nor any hormones and it is a non-GMO, saying that it is not genetically modifying the organism,” Sagi told Reuters in reference to the all-male generation that hatched. 

^{Image credit: Dennis Wright/Flickr. (CC BY-ND 2.0)}