There are over 200 species of jellyfish and most of them are salt water species who are not anywhere close to extinction. The fresh water jellyfish are the ones facing extinction around the world. One of the known species Craspedacusta sowerbyi aka the peach (or orange) blossom jellyfish is usually found in China and is facing extinction. It's existed for roughly 1.5 billion years but the species has become extinct in other geographic areas around the world. Part of theory on why extinction is becoming prevalent because most populations found have all males or all females, making reproduction more challenging.
it lays eggs
No
It only depends what jellyfish. Make sure to be specific in your questions.
jellyfish
moon jellyfish
There are several types of jellyfish found in Australian waters, including the box jellyfish, the Irukandji jellyfish, the bluebottle jellyfish, and the moon jellyfish. Each of these jellyfish species has unique characteristics and can pose a threat to humans.
They do not have many predators. The only ones seaming to be other compass jellyfish, and human pollution. They are not endangered or threatened.
Most of them are not endangered but some are, like the freshwater Craspedacusta sowerbyi Lankester.As of the year 2015 jellyfish are not endangered.There are multiple types of jellyfish, you should try to distinguish which species you are talking about.
Probably not. There is no official census of the lion's mane.
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/
There are over 1,700 jellyfish species known.
I can't speak for all species, but as a general rule, no.