Awesome party trick. Slugs rock.
Sea slug loses penis after sex but grows another the next dayThe astounding warning colours of the nudibranchs, a diverse group of sea slugs, are certainly enough to attract attention — but even they pale in comparison to the gripping news that one species of the soft-bodied molluscs has a habit of discarding its penis.
Nudibranchs are hermaphrodites, meaning that they carry both male and female reproductive organs. Moreover, when they mate, they can perform the male role of donating sperm and the female role of receiving sperm at the same time. This process involves two penises and two vagina-like organs, and sperm transmission effectively happens simultaneously during the encounter.
This is a relatively standard arrangement among nudibranchs, so the creatures' sexual organs might all be expected to look roughly the same. But the animals show incredible sex-organ diversity, and it was during an exploration of this diversity in the species Chromodoris reticulata that researchers made their jaw-dropping discovery.
A Japanese team led by Ayami Sekizawa at Osaka City University and Yasuhiro Nakashima at Nihon University in Tokyo went scuba diving off the coast of Okinawa to collect the sea slugs. They then placed the creatures in aquaria in pairs. In some cases both members of a pair had been isolated from others for 24 hours; in other cases a recently-mated animal was placed with one that had been in isolation.
In total, the team observed 108 pairings, and noticed that individuals that had recently donated sperm seemed to be incapable of doing so again for at least 24 hours. When the researchers looked into this more closely, they noticed that the animals unplugged their penises from their partners and crawled away with their penises dragging along beside them: about 20 minutes later, the slugs discarded their penises. The authors realized that the nudibranchs were not donating sperm again within the 24-hour period because they did not have the necessary anatomy with which to do so.
Devious, treacherous, murderous, neanderthal, sub-human of the West.
Topic: Detachable penis!