5 Incredible facts about jellyfish
Jellyfish don't have brains, hearts, or eyes, and they've been around for over 500 million years of history today's jellies are remarkably similar to their prehistoric ancestors.
Five Amazing Facts about jellyfish
- Jellyfish aren't fish at all. jellyfish aren't really a type of fish. Fish are vertebrates that live in water and breathe through their gills. Jellyfish, on the other hand, are invertebrates, meaning they have no backbone and they absorb oxygen from water through membranes.
- Did you know? jellyfish can kill a fully grown human. The box jellyfish is thought to be the most venomous marine animal in the world. It has a cube-shaped body and is typically found in waters around Australia and the Indo-Pacific. Its tentacles are covered in poison-filled darts. Only a few types of box jellyfish have venom that's lethal for humans, but a person who gets stung by one of these jellies can go into cardiac arrest or die within minutes.
- Jellyfish are almost completely comprised of water. About 5% percent of jellyfish bodies are made of structural proteins, muscles, and nerve cells, while the remaining 95% is water. Human bodies, by comparison, are up to 60% water.
- Over 60,000 jellyfish have been in space. In 1991, over 2,000 jellyfish polyps were blasted into space to test how they reacted to the lack of gravity. Those jellyfish reproduced in space, creating over 60,000 jellies, but the space-bred jellies weren't able to function properly when they returned to Earth.
- A 505million year old fossil suggests jellyfish pre-date dinosaurs Since jellyfish don't have any bones, fossils of ancient jellies are challenging to find. But in 2007, a preserved jellyfish fossil was discovered in Utah that's thought to be over 505 million years old. Dinosaurs lived from about 245 million to 66 million years ago, meaning jellyfish pre-date them by at least 250 million years.