About Fishby Chabala Chisenga | 15-10-2018 15:42 |
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Fish are gill-bearing aquatic craniate animals that lack limbs with digits. They form a sister group to the tunicates, together forming theolfactores. Included in this definition are the living hagfish, lampreys, and cartilaginous andbony fish as well as various extinct related groups. Tetrapods emerged within lobe-finned fishes, so cladistically they are fish as well. However, traditionally fish are renderedparaphyletic by excluding the tetrapods (i.e., the amphibians, reptiles, birds and mammalswhich all descended from within the same ancestry). Because in this manner the term "fish" is defined negatively as a paraphyletic group, it is not considered a formal taxonomic grouping in systematic biology. The traditional term pisces (also ichthyes) is considered atypological, but not a phylogeneticclassification. Source Wikipedia. Thank you for reading.
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