Answer Starfish
These five-limbed creatures can regrow arms that detach from their central disc, and some species have even been observed to complete the process in reverse: regrowing an entire body from a lost arm. To do this the starfish will store nutrients in the arm until it is able to regrow its
Mexican tetra
Researchers in Mexico last week described how they are studying cave-dwelling tetra fish to better understand why some animals can regenerate tissue but others can’t. The scientists performed surgery to remove some of the heart of river fish and cave fish from the species Astyanax mexicanus, finding that while some river fish do regenerate tissue, the cave fish just grew scars over the damage.
Salamander
The amphibious salamander can regrow a lost tail to full length. This process sees cells migrating to the wound and then slowly regenerating the tail within a few weeks. The finished appendage is completely functional and has all the features of the original, with the spinal cord and nerves growing back too.
Axolotl
A relative of the salamander but even more skilled at regenerating is the axolotl. This animal can regenerate not just its tail but also limbs, skin and almost any other body part. Researchers found that each time a limb was removed, it regrew almost perfectly. The pale pink creature has since become the focus of research into human limb regeneration.
Mexican tetra
Researchers in Mexico last week described how they are studying cave-dwelling tetra fish to better understand why some animals can regenerate tissue but others can’t. The scientists performed surgery to remove some of the heart of river fish and cave fish from the species Astyanax Mexicans , finding that while some river fish do regenerate tissue, the cave fish just grew scars over the damage.