There would be no point in defining fish monophyletically anyway, as it would then be just a synonym of craniates. (Also note that “apes, i.e. non-human hominoids, do not include humans” is a tautology but “fish, i.e. non-tetrapod craniates, do not include humans” is not.)
(Of course, you could then say “There would be no point in defining apes monophyletically anyway, as it would then be just a synonym of hominoids.” But hominoids is a much uglier word, and hominoids/hominids/hominines/etc. are much harder to remember than apes/great apes/African apes/etc. (plus, my spell checker baulks at some of the former, FWIW). (See this proposal to rename the scientific names of the clades.)
There would be no point in defining fish monophyletically anyway, as it would then be just a synonym of craniates. (Also note that “apes, i.e. non-human hominoids, do not include humans” is a tautology but “fish, i.e. non-tetrapod craniates, do not include humans” is not.)
(Of course, you could then say “There would be no point in defining apes monophyletically anyway, as it would then be just a synonym of hominoids.” But hominoids is a much uglier word, and hominoids/hominids/hominines/etc. are much harder to remember than apes/great apes/African apes/etc. (plus, my spell checker baulks at some of the former, FWIW). (See this proposal to rename the scientific names of the clades.)