Some fish are able to regrow part or all of their tails when they are lost, including two recently discovered species in Africa, which are known as bichirs. Several types of fish can regenerate the tips of their tails and fins, but not the whole structure.
Tails are considered easier to regrow in fish because, unlike pectoral and dorsal fins, they are not connected to the animal's skeleton. In the bichir fish, the tails and fins are made up of a skin-like material that regenerates when it is lost, such as by another animal biting it off. Other animals that can regenerate tails include salamanders and frog tadpoles.