Through stem cells in the animal’s body. They manage to recreate the eliminated organs from scratch. But that’s not the only secret: regeneration is facilitated because stars have a simplified physiognomy, without blood or brains (their nervous system is spread throughout the body) and with the same vital organs in all arms, in addition to adaptable cells, which manage to transform themselves to take the place of the absent ones.
There are more than 1,900 species of starfish, and for most, regeneration requires that a piece of the central disk still exist. In a few species, however, an entire star can grow from just one part of the arm, albeit an unlikely feat.
Hold the ends!
Animals can live more than 30 years and regenerate indefinitely
– (Marcus Penna/Strange World)
1. There are three cases that lead to regeneration: when the starfish abandons one of its arms when fleeing from a predator, when it is damaged thanks to the attack of other animals or when it reproduces asexually – that is, when it breaks on purpose, generating a new individual from each piece of your disk
– (Marcus Penna/Strange World)
two. The secret is that stars have stem cells in their somatic tissues (not related to reproduction). They can give rise to any type of cell, tissue and organ. But it is necessary that at least a part of the central disc be conserved. In addition to the nerve signal that commands the beginning of regeneration coming from it, it is through it that food intake occurs.
– (Marcus Penna/Strange World)
3. As soon as the loss rolls, the damaged area is covered. Then, yes, the regeneration begins: little by little, the stem cells rebuild the missing arms and also the disc. This takes from several months to up to a year. By having vital organs in all of their arms, these “disabled” stars are able to function properly during this period.
– (Marcus Penna/Strange World)
4. In addition to stem cells, the star has another trump card: established cells are capable of changing roles. One that used to be part of the epidermis, for example, can readapt to make up the digestive system. In some cases, the recovery can go wrong, leaving the animal with deformations in the recovered part or even with more limbs.
Reader Question – Marcos Vinicius Leite, Rio de Janeiro, RJ
Source Regeneration in Echinoderms: Repair, Regrowth, Cloningby Daniela Candia Carnevali