Underwater world, especially sea water so much inhabited by wild animals, ferocious, beautiful and gorgeous. Fish is one of the species of water very beautiful and lots of all kinds and its name. From the start of a very big like sharks and whales, until the fish is very small and clustered. One type of fish that looks wild but wonderful is the arapaima. Arapaima gigas, one of the largest freshwater fishes in the world, and can reach a length of 10 feet and a weight of 440 pounds.