- Jellyfish are thought to pre-date the dinosaurs by millions of years.
- Thousands of jellyfish have been launched into space for experiments.
- Here are 12 things you probably didn’t know about these remarkable animals.
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As beach season gets underway, reports are already emerging of jellyfish sightings and stings. Lion’s Mane jellyfish were spotted in Dublin, Ireland; several beaches in Mexico’s Sinaloa state were closed after hundreds of reported stings; and several Portuguese man-of-wars (a jellyfish relative with a painful sting) have washed ashore in South Carolina.
Although these invertebrates can be frightening, they’re also fascinating and poorly understood.
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.
Here are 12 surprising facts you probably didn’t know about jellyfish.
One type of 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.
A group of jellyfish can go by three different names.
Groups of animals typically have their own names: A group of cows is a herd, for example, while many fish swimming together are a school. Jellyfish groups can go by three different names. A collection of jellyfish are called a "bloom," "smack," or "swarm."
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