Fish 'attracted to gingers'

Fish 'go mad for the ginger gene', a team of scientists have concluded.

In a new study published today scientists found fish were more attracted to bright orange fish than grey ones.

Scientists in the journal BMC Biology found a single gene mutation which turns the medaka a drab grey colour makes them significantly less attractive to the more colourful members of the opposite sex.

The medaka is found in southeast Asia and is seen in a range of colours including brown, orange and grey.

Shoji Fukamachi led a team of researchers from the University of Konstanz, Germany and the University of Tokyo, who studied the effects of alterations in a colour-determining gene on mating preferences of the fish.

Mr Fukamachi: 'We observed that the grey medaka were often rejected in favour of their brown or orange rivals. This is the first demonstration of a single gene that can change both secondary sexual characteristics and mating preferences.'

He added that the greys, however, need not be completely despondent at these findings, as the study also showed that they were preferentially selective for each other.

The orange colour gene in the medaka was over-expressed in some fish by the scientists, making them 'super attractive bright orange'.

The scientists said this resulted in induced hyperactivity in similarly engineered members of the opposite sex while other potential mates were ignored almost completely.

'Thus, the present finding of the xanthophore-dependent mate choice enables many ingenious experiments to be designed in this and other fish species. This discovery should further facilitate molecular dissection/manipulation of visual-based mate choice,' Mr Fukamachi concluded.