However , traditionally fish are rendered paraphyletic by excluding the tetrapods ( i.e. , the amphibians , reptiles , birds and mammals which all descended from within the same ancestry ) .
Tetrapods emerged within lobe - finned fishes , so cladistically they are fish as well .
Traditionally fish are rendered paraphyletic by excluding the tetrapods ( i.e. , the amphibians , reptiles , birds and mammals which all descended from within the same ancestry ) .
Tetrapods emerged within lobe - finned fishes , so cladistically they are fish as well .