News & Views
Indonesian research probes sex reversal in common carp
By Ruby Gonzelez
An all-natural treatment was used in the sex reversal of common carp (Cyprinus carpio) and resulted in as much as 80 percent female larvae.
By Ruby Gonzelez
Extract from the leaves and stalks of turkey berry was used in a research conducted by Triayu Rahmadiah, Muslim and Ade Dwi Sasanti, of the Sriwijaya University in Indonesia, to determine the effect of the plant extract as phytoestrogens on the feminization of common carp.
Phytoestrogens may affect the development of the reproductive and sex differentiation in fish.
Leaves and stalks were used because of their higher content of steroids.
Larvae were immersed for 24 hours in a solution of 300mg of turkey berry leaf and stalk extract per 1 liter of water. The larvae were then transferred to a 40-liter aquarium. During the 35-day rearing period, they were fed with natural food and artificial feeds.
The other treatments contained 0, 100, 200 and 400 mg of turkey berry extract. It was observed that while the highest percentage of female common carp was produced in the 300 mg treatment, there was a decrease in the percentage of female in 400mg treatment. Authors said there are symptoms of a paradoxical effect “that high doses for certain species will have the opposite effect and can result in high mortality.”
Female carp is valued over male carp because they grow faster.
Using turkey berry extracts for the carp sex reversal, is “in line with the global trend of the people who take the slogan ‘back to nature’ so that the demand for food use and the production of natural ingredients needs to be increased by using herbal drugs or phytoestrogens,” the authors said.
The research was published in the International Journal of Fisheries and Aquatic Research.