You’ve heard the phrase ‘cutting off the nose to spite the face’, but what about cutting off the entire head to spite the body? This may sound nonsensical at first, but a certain species of sea slug known as the Sacoglossan sea slug would beg to differ. A recent study out of Japan has found that a species of sea slug is able to willingly remove its own head in order to grow a new body.
The unusual discovery was made by Sayaka Mitoh from Nara Women’s University in Japan. Not only did she discover that the sea slug is able to remove its own head, but she also found that once the head was detached from the body it was able to move around and consume algae.
The process of removing its own head is known as autotomy, which involves the sea slug dissolving its neck tissues, then tearing its head free from the body. Unsurprisingly, this is the first time researchers have come across an animal that willingly removes its own head and grows a new body. Geckoes are known to remove their tail of limbs to get away from predators, but not to the extent of removing their entire head.
Sacoglossan sea slugs don’t mind losing their heads. Not only can the sea slugs elect to detach their heads and survive, but they can regrow a whole new body. Read more in @CurrentBiology https://t.co/7ueo5HL0Vn@NaraWomensUniv
Video: Sayaka Mitoh pic.twitter.com/oL5bh9psQ7
— Cell Press (@CellPressNews) March 8, 2021
The exact reason as to why the sea slug does this remains unknown, but researchers believe self-preservation could play a big role in this process. Once the head was completely detached from the body, researchers discovered that the body was filled with parasites, while the newly grown bodies were completely parasite-free.
This is not just a once-off trick either, as researchers noted that one slug removed its head twice during their studies. The old bodies, parasite-filled bodies were also able to react to certain stimuli for up to multiple months after being removed from the body.
On average, it took the slugs around three weeks to completely grow their new bodies. During this period of regrowth, the slugs were able to sustain themselves through the process of photosynthesis.
Take a look at a full breakdown of the study by clicking here.