Four unique insects have been found deep inside Brazil's caves where the female has a 'penis' that she inserts into the male's 'vagina' during their 40 to 70-hour mating session.
Scientists have discovered four insect species in Brazil that dwell in extremely dry caves, feed on bat guano, and possess what researchers call an ‘evolutionary novelty’. The female has an elaborate, penis-like organ while the male has a vagina-like opening into which a female inserts her 'penis' during mating, which can last 40 to 70 hours, the scientists reported in the journal Current Biology.
Researchers say these attributes make the four species of the insect genus Neotrogla unique in the world. “Evolution of novelties like a female penis is exceptionally rare. That’s why I was really surprised to see the structure,” says entomologist Kazunori Yoshizawa of Japan’s Hokkaido University. Yoshizawa says that although sex-role reversal has been documented in different types of animals, these insects are the sole example in which the “intromittent organ” – the penis – is reversed.
Neotrogla insects are small, betwen 2.7mm and 3.7mm in length. Superficially, they look like flies, with nothing particularly unusual about their appearance aside from their genital structures. Scientists are calling the female penis structure a gynosome. During mating, she inserts it into a male and receives sperm. Once inserted, part of the gynosome inflates and spines internally anchor the insects together.