<p style="margin: 0pt;">A mosaic jellyfish floats serenely in the waters of the Coral Sea, about 100 nautical miles from Cairns, Australia. Jellyfish are ubiquitous in the Earth’s oceans. They can thrive in warm water and cold, along coastlines or out in the deep. Their bodies are about 95 percent water. And though they have no brains, jellyfish have somehow been smart enough to survive for over 500 million years.</p>

Mosaic Jellyfish

A mosaic jellyfish floats serenely in the waters of the Coral Sea, about 100 nautical miles from Cairns, Australia. Jellyfish are ubiquitous in the Earth’s oceans. They can thrive in warm water and cold, along coastlines or out in the deep. Their bodies are about 95 percent water. And though they have no brains, jellyfish have somehow been smart enough to survive for over 500 million years.

Photograph by Melissa Fiene, My Shot

Jellyfish

Jellyfish aren’t fish but invertebrates, animals that lack backbones and even brains. Yet 30,000-odd species do far more than survive—they thrive in ocean waters the world over.

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