What is dangerous about jellyfish?

I see you're new here Mullah B welcome. Some jellyfish are poisonous many are not. Since you asked about dangerous ones I'll focus on those, why their dangerous and how they they do it. Most species have tentacles loaded with stinging cells called nematocysts. read more

Most Dangerous Jellyfish 7 November 25, 2013 For an animal (just) that is 95% water, has no brain and eats / defecates out of the same opening the jellyfish have a surprisingly complex and effective weapon at their disposal. read more

Aside from box jellyfish though, as you can see, there are really not many dangerous jellyfish. There is the Man o’ War (which barely counts), and the Sea Nettle and Lion’s Mane jellyfish, but other stinging jellies like the Moon and Cannonball are relatively harmless. read more

Jellyfish are aquatic creatures classified in the phylum Cnidaria along with other sea creatures such as corals and sea anemones. The body of a jellyfish is about 95% water and 5% solid matter, and it lacks elaborate body systems like those found in most animals. read more