Questions:

1. How long have jellyfish existed?

1.  How many jellyfish species are there?

1. What percentage of jellyfish is made out of water?

1.  Which type of jellyfish is said to be immortal? 

Answers:

1. More than 600 million years!

1. About 300,000 different species!

1. 98% water! Jellyfish also do not have brains!

1. The Turritopsis Dohrnii jellyfish!

Citations

https://www.oneearth.org/five-jaw-dropping-facts-about-jellyfish/

https://www.foodnavigator.com/Article/2019/07/30/Jellyfish-A-new-sustainable-nutritious-and-oyster-like-food-for-the-Western-world