Thread:Original TMNT Cartoon Fan/@comment-995426-20190504130449

Yes, there are fish who live out of water.

See the Wikipedia articles for and s, which are fish who can live out of water. And though they are generally the exception among modern non-tetrapod fish, bony fish do have an evolutionary history of breathing atmospheric oxygen: Interestingly enough, the s of most bony fish actually evolved from a previous lung that gained and then lost the ability to breathe air. (More divergent branches of fish like sharks and rays never had lungs, and do not have a swim bladder.)

And technically, all terrestrial vertebrates (including humans) originally evolved from. In fact, you may observe that Turtlepedia categories for real life species largely observe a structure (a tree of evolutionary branching), so that Category:Humans are a subcategory of Category:Apes, and so on through Category:Primates, Category:Mammals, Category:Reptiles, Category:Amphibians and Category:Fish. And while it would make very little sense to directly categorize characters like Splinter or Leatherhead as fish (they are not fish in the familiar sense), they are still fish cladistically, and are covered as such indirectly by the parent category hierarchy.

Among other TMNT characters, there's also incarnations of Man Ray and Xever Montes as well as Bludgeon, who primarily live on land but can also swim. And if I recall correctly, it's never specifically said that the Other cannot swim. :) 