Image being able to ‘just’ get rid of your body (and regrow a replacement one of course) when it’s giving you a hard time. That would be amazing when the aches and pains become, well, a pain. Researchers have just discovered two species of sea slug that do exactly that! The two species have been shown to shed their entire body (including major organs with the exception of the brain) and grow a new one when their parasite load becomes too high. Iinstead of trying to fight off the parasites, they simply let them go.

While they are busy growing their new body they ‘steal’ energy by incorporating the chloroplasts from their algal meals – which is then used for photosynthesis (known as kleptoplasy). This is a big step up from the usual instances of species being able to regrow something after willingly shedding them (autotomy) – which usually involves shedding a limb/appendage…

The shedded bodies never regrow a head – which begs the question if the headless horseman features in any of the sea slugs horror story lore – or, you know, if there are just a whole host of bodies floating around…

The full research article can be found here: https://doi.org/10.1016/j.cub.2021.01.014