Recently, in the journal "Contemporary Biology" published a paper called "Extreme autotomy and whole-body regeneration in photosynthetic sea slugs", it can be said that it broke through human cognition, a creature called sea slugs will actively break their necks, and then re-grow the body.
<h1>Sea slugs severed head regeneration</h1>
The sea slug is not a slug, but a species of snail, a suborder of the sea hare family Marine gastropods, with two pairs of antennae protruding like rabbit ears. Sea slugs are shellfish living in shallow seas. It is a special member of the mollusk family. Their shells have degenerated into inner shells. Eleven species of sea slugs have been found, all living on the silty seafloor of intertidal water zones along the coast.
Hayaka Mito, a doctoral student in the Department of Biological Sciences at Nara Women's University in Japan, discovered that the head of a sea slug in her lab had fallen out of nowhere.
We need to know that in nature, without the heart and important organs, it is difficult for living things to survive, but after the sea slugs cut off their heads, not only did they not die, but the head was still eating seaweed leisurely.
After a few weeks, the head grew a whole new heart and body.
Mito Hayaka discovered that the sea slugs were dissolving cells near their necks and then ripping off their heads. After the head-body separation, the body of the sea slug still reacts, but it is not as active as the head, and the body can still move if it is stimulated before it completely decays.
After several years of research, Mito Hayaka discovered two species of sea slugs, the Elysia cf. marginata) and the deep-edge sea cow (Elysia atroviridis) have such abilities.
<h1>Why severed head regeneration</h1>
We all know that when geckos, lizards and other animals are bitten by predators or encounter danger, they often cut off their tails to attract the attention of the enemy and take the opportunity to escape. This can be said to be a way of survival that sacrifices the part and preserves the whole. This is a survival skill of self-defense, which can also be said to be instinctive.
Previously, scientists agreed that salamanders have the strongest regenerative power, and no other animal can match their regenerative ability, including limbs, tail and spinal cord, parts of the eyes (such as the retina and lens), brain, heart and chin. For example, when salamanders lose a leg, they produce large numbers of cells at the stumps— called bud groups— from which they eventually regenerate a new, fully functional leg.
And the ability of sea slugs to regenerate such a severed head is not available even to salamanders. We need to know that for other animals, without the heart and body, it is impossible to absorb nutrients, and even if the mouth can eat, it has no meaning.
But sea slugs are different, some sea slugs can store chloroplasts obtained from algae into horned gills, thereby using photosynthesis to replenish their own energy, and there is a more BUG sea slug - green leaf sea slugs, directly into the body, so that they can really become walking "green leaves", so that without eating, the descendants of these sea slugs can also produce their own chlorophyll, but before eating enough algae to obtain the necessary chloroplasts, They cannot yet photosynthesize.
Green leafy sea slugs
This also means that even without the heart and body, sea slugs can provide energy to the head by ingesting the chloroplasts of the algae for photosynthesis, thus ensuring the survival of the head.
Coupled with the fact that the head of the sea slug is small, the energy required is also small, so there is no need to promote the flow of blood and nutrients.
Scientists believe that the reason why sea slugs are severed to survive is because the body of sea slugs is infected with parasites, and a new body can be obtained through such releases. But this explanation only applies to deep-edge sea cows, which can regenerate even if their bodies are free of parasites.
For example, scientists have found that an old edge sea cow, if it continues to regenerate its head, it will soon die, and the severed head regeneration, to obtain a new body, can also extend a certain life span.
But this is risky for the elderly sea slugs, who die on day 10 because they are too old to get enough energy for their heads.
At present, scientists are further studying sea slugs, hoping to grasp the regeneration mechanism of sea slugs.
<h1>significance</h1>
While we may never have the incredible regenerative power of sea slugs, if in the future, we can acquire this gene of sea slugs, such as editing them in humans, humans will be able to increase their ability to recover from injury.
In addition to this, this tiny creature is likely to continue to provide us with insights into "tissue regeneration, wound healing and repair in mammals."