What is fish-meaning?

Fish are aquatic animals characterized by their streamlined bodies, gills for breathing, and fins for swimming. They are cold-blooded and lay eggs. Fish are found in both saltwater and freshwater environments all over the world, ranging in size from tiny species like the goby to huge ones like the whale shark. Fish are important to the global ecosystem as both a food source for humans and other animals, and as vital members of aquatic food webs. Hundreds of fish species are currently endangered, largely due to overfishing and habitat destruction.