Antarctic molluscs 'switch sex'

Antarctic bivalves have surprised scientists who have discovered that the animals switch sex.

The reproduction of Lissarca miliaris was studied in the 1970s and the species was first described in 1845.

But their hermaphrodite nature had remained unknown until they were studied by scientists from the National Oceanography Centre, Southampton.

Researchers suggest the molluscs could switch between the sexes to efficiently reproduce in the extremely cold ocean.

The results are published in the journal Polar Biology.

"The previous reproductive study only looked at the large eggs and broods," said PhD student and lead author Adam Reed.

This earlier work showed how females brood their young for up to 18 months, from "large yolky eggs" to "fully shelled young", and found that females can support as many as 70 young inside their hinged shell.

But concentrating on reproduction at a cellular level, Mr Reed and colleagues discovered that the eggs were actually present in males.

Continued:  http://www.bbc.co.uk/nature/19543557