History
Jellyfish have existed since before dinosaurs, for over 500 million years, making them one of the oldest living creatures on Earth. These gelatinous, free-floating animals belong to the phylum Cnidaria and have thrived since the Cambrian period. Over time, jellyfish have adapted to various marine environments, from the deep sea to coastal water.
The Anatomy of a Jellyfish
Jellyfish have no brain, heart, or bones. They are made up of a smooth, gelatinous bell that helps them float and move through water by contracting and relaxing, attached to tentacles armed with tiny, stinging cells. These stingers, called nematocysts, are used to capture prey and defend against predators by injecting venom. While many jellyfish lack eyes, some species, like the box jellyfish, do possess simple eyes that can detect light and dark, aiding in navigation.
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