Posted on 05/15/2005 12:37:27 PM PDT by mathprof
For certain fish species to survive, the male genitalia should be large enough to attract the females, and small enough to escape predators, stated a study presented in the proceedings of the National Academy of Sciences.
The study was to find the female sexual preference and male swimming performance in two species of mosquitofish -Western and Bahamas mosquitofish.
In the study, researchers analyzed the gonopodia (modified fin) in the mosquitofish that transfer sperm to females. Mosquitofish can not retract their gonopodia and they swing them during courtship.
Researchers concluded that the females preferred to spend time watching videos of males displaying digitally enlarged gonopodia rather than those with average-size gonopodia. This indicates that a larger gonopodium is the female sexual preference.
However, larger gonopodia make the males more susceptible to predation, because the males with larger gonopodia swim slower.
"Our results suggest that both mating selection, favoring larger genitalia, and natural selection, favoring reduced size, may direct evolution and diversification of genitals," said Layman, co-author of the study.
The study was conducted by Craig A. Layman in Yale University, and colleagues Brian Langerhans at Washington University and Thomas J. Dewitt at Texas A&M University.
There's always a bigger fish.
Heck, who doesn't?
Lots of witty replies to this same topic over here http://www.freerepublic.com/focus/f-chat/1401171/posts
They don't call it a codpiece for the halibut.
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