Fish

Epic card · No. 9182

A fish is an aquatic, anamniotic, gill-bearing vertebrate with a tough cranium to protect the brain. Many fish have fins that they use for directional stability and propulsion. Fish can be grouped into the more basal jawless fish and the more common jawed fish, the latter including all living cartilaginous and bony fish, as well as the extinct placoderms and acanthodians. Tetrapods are descended from fish, so in a break from the long tradition of grouping all fish into a single class (Pisces), modern phylogenetics views fish as a paraphyletic group that includes all vertebrates except tetrapods. To treat fish as a monophyletic group, one would have to classify tetrapods as a clade/subgroup of specialized fish, which would make "fish" and "vertebrates" synonyms. In English, the plural of "fish" is fish when referring to individuals and fishes when referring to species. Most fish are cold-blooded, their body temperature varying with the surrounding water, though some large, active swimmers...

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