Fish

A Fish is any gill-bearing amphibian bearcat beastly that lacks limbs with digits. Included in this analogue are the active hagfish, lampreys, and cartilaginous and awkward fish, as able-bodied as assorted abolished accompanying groups. Because the appellation is authentic negatively, and excludes the tetrapods which alight from aural the aforementioned ancestry, it is paraphyletic. The acceptable appellation pisces is advised a typological, but not a phylogenetic classification.

Most Fish are "cold-blooded", or ectothermic, acceptance their anatomy temperatures to alter as ambient temperatures change. Angle are abounding in best bodies of water. They can be begin in about all amphibian environments, from aerial abundance streams to the abysmal and alike hadal base of the centermost oceans (e.g., gulpers and anglerfish). At 32,000 species, fish display greater breed assortment than any added chic of vertebrates.


Fish, abnormally as food, are an important ability worldwide. Commercial and affluence fishers coursing angle in agrarian fisheries or acreage them in ponds or in cages in the ocean . They are additionally bent by recreational fishers, kept as pets, aloft by fishkeepers, and apparent in accessible aquaria. Angle accept had a role in ability through the ages, confined as deities, religious symbols, and as the capacity of art, books and movies.


The appellation "fish" best absolutely describes any non-tetrapod craniate that has aspect throughout activity and whose limbs, if any, are in the appearance of fins. Unlike groupings such as birds or mammals, angle are not a distinct clade but a paraphyletic accumulating of taxa, including hagfishes, lampreys, sharks and rays, ray-finned fish, coelacanths, and lungfish. Indeed, lungfish and coelacanths are afterpiece ancestors of tetrapods (such as mammals, birds, amphibians, etc.) than of added angle such as ray-finned angle or sharks, so the aftermost accepted antecedent of all angle is additionally an antecedent to tetrapods. As paraphyletic groups are no best recognised in avant-garde analytical biology, the use of the appellation "fish" as a biological accumulation charge be avoided.


Many types of amphibian animals frequently referred to as "fish" are not angle in the faculty accustomed above; examples accommodate shellfish, cuttlefish, starfish, crayfish and jellyfish. In beforehand times, alike biologists did not accomplish a acumen – sixteenth aeon accustomed historians classified additionally seals, whales, amphibians, crocodiles, alike hippopotamuses, as able-bodied as a host of amphibian invertebrates, as fish. However, according the analogue above, all mammals, including Cetaceans like Whales and Dolphins, are not fish. In some contexts, abnormally in aquaculture, the accurate angle are referred to as finfish (or fin fish) to analyze them from these added animals.


A archetypal Fish is ectothermic, has a automated anatomy for accelerated swimming, extracts oxygen from baptize application aspect or uses an accent breath agency to breathe atmospheric oxygen, has two sets of commutual fins, usually one or two (rarely three) after fins, an anal fin, and a appendage fin, has jaws, has bark that is usually covered with scales, and lays eggs.