The Cool Dow

See all Largest and heaviest fish Ocean sunfish Whale shark Basking shark Beluga sturgeon Greenland shark Keep learning Click for an immersive and interactive 3D experience View 3D model Life cycle Spawning Fish release eggs and sperm into water for fertilization. Hatching Fish embryos emerge from eggs after incubation. Juvenile stage Fish juveniles grow in size, shape, and color, and develop functional organs. Maturity Fish reach sexual maturity and are able to reproduce. See all A gill-bearing aquatic craniate animal  that lacks limbs with digits. Diet fish, worms, crustaceans Largest breed Whale shark Smallest breed Paedocypris Progenetica Popular breed Goldfish Fish has  a closed-loop circulatory system . The heart pumps blood in a single loop throughout the body. Most fish possess  highly developed sense organs . Nearly all daylight fish have color vision  that is at least as good as a human's. There are some species of fish that can  produce sounds  by rubbing or grinding the