Lange et al., Proc. Royal Soc. B, Nov. 2013.
Photograph of a reciprocal sea-slug mating with both stylets inserted into the mating partners’ foreheads. [Caption altered from original for clarity and brevity.]
Sea slugs: Who knew they lead such interesting private lives?
This is Sandra Tsing Loh with the Loh Down on Science.
You may not spend your days considering the mating rituals of Australian sea slugs, but there are people who do. Researchers at the University of Tubingen, in Germany, for instance.
Sea slugs are hermaphrodites, which means they have both male and female parts. They also have an extra appendage called a stylet, which they use like a hypodermic needle to puncture their partner and inject hormones. No one is sure why, but it may boost insemination.
The Tubingen team wanted to know if there was any rhyme or reason to where the slugs wounded their mates. Some species vary injection sites. Not the romantically named Siphopteron species 1. It always seems to puncture its partner in the head—right between the eyes, in fact! Ouch!
Luckily, both partners do it. Why? Researchers haven’t figured that out yet. They speculate that the injections may be some form of neural control that makes their partners, oh, I don’t know, more agreeable?
You could say, with hermaphroditic sea slugs, love goes to their heads. Or not.
***** For more 90-SECOND SCIENCE FACTS, click here.*****
The Loh Down on Science is produced by LDOS Media Lab, in partnership with the University of California, Irvine, and 89.3 KPCC. And made possible by the generous support of the Gordon and Betty Moore Foundation.