Cricket balls bowl over scientists

Scientists say a species of bushcricket has the biggest testicles of any creature on Earth - proportionately.

The bushcricket's testicles account for up to 14% of its body weight - equivalent to a human with testicles weighing 5kg (11lbs) each.

Karim Vahed of the University of Derby and his team began their studies by measuring the testicle size of 21 species of bushcrickets, reports the BBC.

They found that one species - Platycleis affinis - far surpassed the previous record for the proportionally largest testicles.

The previous holder was a species of fruit fly - Drosophila bifurca - whose testicles to body weight ratio has been recorded as 10.6%.

However, a study of the bushcricket's mating strategies revealed they released only small amounts of sperm at each mating.

That suggests the big testes are for mating with many females, not producing competitive volumes of sperm for each encounter.
"Males with bigger testicles are actually producing smaller amounts," Dr Vahed told BBC News.

"This very much favours the alternative hypothesis: that it's about the number of different females the male can fertilise, rather than getting a greater success per female."

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