jellyfish still aren't extinct maybe a specific jellyfish
No jelly fish are not extinct.
Yes, or they would be extinct.
When they go extinct or are about to go extinct, they are called endangered. This usually happens when there is a widespread famine, drought, etc.
Eventually wildlife will go extinct and we will have no source of food and therefore WE will go extinct. So in the long run, without wildlife: WE DEAD!
No, the turritopsis nutricula jellyfish is not extinct. Since, scientists are studying on them. Also, these type of jellyfish's population is increasing. Since, they could turn back into their polyp state again.
Japanese Crested Ibis is extinct
It is an endangered tree. It was thought to be extinct. It is from the island of Mahé within the Seychelles archipelago.http://www.arkive.org/jellyfish-tree/medusagyne-oppositifolia/
I can't speak for all species, but as a general rule, no.
the jellyfish it eats will get over populated
It dies.
it hurts