Fish species at risk
A fish is any member of a paraphyletic group of organisms that consist of all gill-bearing aquatic craniate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups. Most fish are ectothermic, allowing their body temperatures to vary as ambient temperatures change, though some of the large active swimmers like white shark and tuna can hold a higher core temperature.
Fish are an important resource for humans worldwide, especially as food. Commercial and subsistence fishers hunt fish in wild fisheries or farm them in ponds or in cages in the ocean . They are also caught by recreational fishers, kept as pets, raised by fishkeepers, and exhibited in public aquaria.
Fish have had a role in culture through the ages, serving as deities, religious symbols, and as the subjects of art, books and movies.