Colorful Freshwater Fish HD
Channel: Nature 360
Date: 2020-08-17

All fish share two traits: they live in water and they have a backbone—they are vertebrates.

Apart from these similarities, however, many of the species in this group differ markedly from one another. Fin fish like salmon have gills, are covered in scales, and reproduce by laying eggs. Eels, by contrast, have worm-like bodies and exceedingly slimy skin. Lungfish gulp air. Whale sharks, the largest fish, give birth to live young and eat only tiny fish, squid, and plankton. Some species, such as the weedy sea dragon, are so bizarre they seem almost unreal.

Fish have developed special senses, too. Because water transmits sounds, disperses chemicals, and conducts electricity better than air, fish rely less on their vision and more on their hearing, taste, and smell. Many can detect motion in the water using a special row of scales with sensors known as the lateral line. Others can find their prey and even navigate by detecting electrical charges.