Scientists have discovered the first case of gender-reversed genitalia, found in a species of Brazilian cave bugs.
Researchers are saying that the female cave bugs, which have a penis, are the first example of the "intromittent organ," meaning the male organ, is reversed and placed on the female, reports the Los Angeles Times. Some instances of sex-role reversal have been found in other animals and insects before, such as the seahorse, but the Brazilian cave bug is an “evolutionary novelty” because of the male-to-female anatomical switch.
The insects are small and resemble flies, and are completely ordinary except for their sex organs. Reuters reports that the reproductive organs of the female bug are called a gynosome. During mating, the female bug inserts her gynosome into the male bug to receive sperm, which locks the two bugs together for as long as 70 hours.
Entomologist Kazunori Yoshizawa of Hokkaido University in Japan believes that this unique mating setup places the female bug into an unprecedented position of power. "Because the female anchoring force is very strong, a male's strong resistance may cause damage to his genitalia. Therefore, it is very likely that entire mating processes are controlled actively by females, whereas males are rather passive," Yoshizawa said.