Barnacles can drastically change penis size to have sex

Washington, Feb 7 : Barnacles can totally change the size and shape of their penises to battle the waves and have sex, a new study has found.

Graduate student Christopher Neufeld and Dr. Richard Palmer from the Department of Biological Sciences at the University of Alberta discovered that these distant relatives of crabs and lobsters can alter the size of their penises up to 8 times their body length, in order to mate.

The authors said that barnacles want to mate but are permanently bound to whatever rock or hull they once latched onto. Because of this condition, barnacles have evolved the longest penises of any creature for their size to seek out and have sex with their neighbours.

Neufeld and Palmer have shown that barnacles appear to have acquired the capacity to change the size and shape of their penises to closely match local wave conditions.

When wave action is light, a longer (thinner) penis can reach more mates, but at times of higher wave action, a shorter (stouter) penis is more manoeuvrable in flow and therefore can reach more mates.

The research suggests that sexual selection, competition with other males, female choice, sexual conflict between males and females, is not required to explain variation in genital form.

In barnacles, this variation appears to be driven largely by the hydrodynamic conditions experienced under breaking waves, the authors said.

The study is published in Proceedings of the Royal Society B.

ANI