Jellyfish are found in all the planet’s oceans: they live both on the water’s surface and in the deepest waters, and a few species can even live in fresh water lakes. There are about 1,500 known species, and every day more are being discovered.
These animals have lived on Earth for more than 600 million years, making them older than dinosaurs! Of all existing jellyfish species, only about 70 are truly dangerous to man. Being stung by a jellyfish is like being hit by tiny poisonous arrows.
Every jellyfish has tentacles that contain stinging cells; when a jellyfish is hit by a foreign body, it releases stingers which resemble actual little harpoons. The stinger kills or stuns its prey so the jellyfish can capture it with its tentacles and feed from it.