You may think you know what a fish is, but this group of animals actually has a very specific definition. To be a fish, the animal must have specific physical features:
Fish biologists have described more than 30,000 species of fish in the world. Visit NPSpecies to see what species of fish are found in national parks.
Scientists classify fish into two major groups: the jawless (Agnatha) fishes and the jawed (Gnathastomata) fishes.
Native Fish in Parks
National parks contain about 60% of all native freshwater fish species that occur within the United States. Many unique, native fish make their homes in national parks.
Last updated: February 13, 2018