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megimoo
01-14-2009, 03:25 AM
:rolleyes:Butterflies use penis to gauge sex competition :D

BUTTERFLY sex is not as elegant an affair as you might think. It seems that male monarch butterflies conduct an all-out sperm war based on a crude measure of how much sperm is stored inside a female from a previous mating.

During sex the males physically restrain the females for an entire day while injecting them with a fluid which contains fertile sperm as well as seemingly functionless cells without nuclei.

Michelle Solensky of The College of Wooster in Ohio paired male monarch butterflies with a selection of females that had had different numbers of partners.

She found that males could selectively increase or decrease the amount of fertile sperm in their deposits. For example, they deposited slightly more into a female for each of her previous mates (Animal Behaviour, DOI: 10.1016/j.anbehav.2008.10.026). "This may explain earlier observations that the last male to mate has a reproductive advantage," says Solenksy.

She then arranged for some female butterflies to receive a large deposit from a single male, and others to have a small deposit from three different males adding up to a similar volume.

When males later mated with the females, they used the same amount of sperm irrespective of which experimental group the female butterfly had been in. This showed that the males were adjusting their sperm on the basis of volume - not the number of previous partners.

"I don't know of any other creatures that respond to the amount of sperm inside their mates," says Solensky. "The new aspect for butterflies is that they can assess the intensity of sperm competition without ever witnessing previous matings," says Simone Immler at the University of Sussex in the UK.

Because monarch butterflies do not use chemical signals like pheromones, Solensky suspects that sensors on the male penis detect the volume directly, like the dipstick in a car's oil tank. If so, the cells that lack nuclei may act to bump up the volume of the deposit and discourage rivals.
http://www.newscientist.com/article/mg20126903.400-butterflies-use-penis-to-gauge-sex-competition.html

jinxmchue
01-14-2009, 08:09 AM
During sex the males physically restrain the females for an entire day while injecting them

Lucky bastards.

noonwitch
01-14-2009, 08:47 AM
:rolleyes:[
During sex the males physically restrain the females for an entire day while injecting them with a fluid which contains fertile sperm as well as seemingly functionless cells without nuclei.
"http://www.newscientist.com/article/mg20126903.400-butterflies-use-penis-to-gauge-sex-competition.html



Butterflies are as bad as ducks, although ducks commit gang-rape.

megimoo
01-14-2009, 09:51 AM
Lucky bastards.They can still nag them about their 'little jewels'!