Yesterday Justin, in Grade 6, was telling Mr. Weber about this jellyfish that is immortal. “As if,” thought Mr. Weber. “This cannot possible be true; it must be a misunderstanding.”
Well, after further investigation*, it turns out he was right! This is the only known case of an animal capable of reverting completely to a sexually immature, colonial stage after having reached sexual maturity as a solitary stage. That is kind of like a chicken being able to revert back to being an egg. Basically, when the jellyfish is exposed to environmental stress or physical assault, or is sick or old and begins to disintegrate something strange happens . . . its life cycle starts to move in reverse. A large portion of its body and tentacles deteriorate, and it eventually becomes a cyst. It can then, miraculously, reactivate genetic instructions from earlier in its lifecycle, and it actually starts creating new polyp cells. From there, the life cycle begins moving forwards again. This all happens within five days of the jellyfish’s “death.” Scientists say that this could technically continue indefinitely.
http://submergemag.com/blogs/i-dont-think-youre-ready-for-this-jelly/9642/ (note: includes some strong language)