Bengaluru scientists revive endangered fish species

A team of scientists at the Central Institute of Freshwater Aquaculture (CIFA) in Bengaluru have revived Hypselobarbus pulchellus, an endangered fish species of peninsular India, using the induced breeding technique.

Induced breeding is a technique whereby fish are stimulated by pituitary hormone to breed in captivity.

This is the first time that scientists here have been successful in induced breeding technique. For the past 50 years, the efforts for induced breeding of this fish were unsuccessful.

The fish, known as ‘Haragi’ or ‘Hullugende’ locally, is endemic to Karnataka waters and once formed an important fishery of the river Tungabhadra. The indiscriminate exploitation of rivers and lack of conservation put many of these fish into the category of threatened, vulnerable and rare species.

Dr N Sridhar, principal scientist and his team at CIFA’s regional research centre, have been studying the reproductive biology and induced breeding of this fish — classified as critically endangered (possibly extinct) by the International Union for Conservation of Nature (IUCN) Red List — since 2003.

Though initial success was achieved during 2009, it could not be sustained due to visceral fat formation in the abdomen of the fish. By conducting invitro hydrolysis of feed ingredients, Dr Sridhar identified that the traditional feed — containing rice bran and groundnut oil cake — was causing impaired ovary development among the female fish species.

In 2015, a special feed was developed at the centre to overcome the visceral fat formation.

“The new feed ultimately resulted in maturity of the female fish,” said Dr Sridhar, adding, the first generation of the induced bred healthy fingerlings is now being successfully reared at the centre.

“A part of the fish fingerlings will finally be river ranched at Tunga River in Gajanur, Shivamogga in order to enhance this fish stock in the river once they attain a size of about 100 mm,” Dr Sridhar stated.