Male crickets strengthen the potency of their sperm if they can hear competition

By AG Staff 30 August 2017
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Because female crickets can increase their chances of reproductive success by choosing multiple partners, male crickets have had to develop ways to cope with the stiff competition.

AUSTRALIAN RESEARCHERS have found that when male crickets can hear the mating calls of other male crickets, they increase the potency of their sperm to ensure reproductive success.

While it’s well understood that female crickets have an increased chance of reproductive success if they choose multiple partners, previously little was understood about how males tackled this threat of intense competition.

To evaulate possible defense mechanisms to this competition, scientists from the University of Western Australia exposed one group of developing crickets to the calling and courtship of approximately 100 sexually active adult crickets, while another group of crickets were raised in isolation.

“We found that male crickets exposed to the calls of rivals during development produced ejaculates containing a higher proportion of viable sperm than males reared in silence,” said Leigh Simmons, the lead author of the paper.

The male sperm was made more viable through the presence of a particular protein gene.

Leigh explained that the threat of competition, bolstered by a females desire for multiple partners isn’t restricted to crickets.

“Socially mediated changes in gene expression have been reported previously, in the context of pre-mating sexual selection,” he said.

“Rapid increases in the expression of genes in various regions of the female brain have been documented in response to social exposure to courting males, in fish, birds and insects, with these changes in gene expression often being of greater magnitude when females experience more attractive males.”

These new findings add to the growing knowledge of how different male animals are coping with the stiff competition. 

The research was published in the Royal Society.