Paris - Female trout fake an orgasm, apparently to find a better mate, according to Swedish research reported next Saturday in the British weekly New Scientist.
When courting pairs of brown trout prepare to spawn, both fish quiver violently, with their mouths gaping. At that point, eggs and sperm are usually released simultaneously to maximise the chances of fertilisation.
Erik Petersson and Torbjoern Jaervi of the National Board of Fisheries watched trout in an aquarium and found that females faked spawning in 69 out of 117 couplings.
"The females behave as if they should spawn," Jaervi told New Scientist. "They trick the males into releasing their sperm."
The more false orgasms a female had, the more males were present when she finally released her eggs.
The apparent reason for this is to give the female a wider choice of prospective mates, thus providing an insurance against male infertility.
Most females eventually spawned with the male they tricked, but sometimes they plumped in favour of hunkier males with bigger fins and jaws, a sign of genetic superiority.
The research is reported in full in a specialist journal, Animal Behaviour. - Sapa-AFP
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