Fish that turn into sleeping bags

The parrotfish are found in shallow coastal waters in the seas. Some parrotfish species cover themselves in a gelatinous substance especially at night before they sleep. This substance is produced by the fish from mucus from the glands located at the upper edge of the gill cavity. They form this protective sheath so that other fish of prey cannot smell them out at night.

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Sharks are more ancient than dinosaurs

Sharks are fish which have cartilages rather than bones. These fish evolved earlier than dinosaurs, which were reptiles. The fossil records show that sharks existed about 400 million years ago. Dinosaurs were found during the Triassic period, i.e. about 225 million years ago.

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