Nah, phylogenetically speaking, all descendants of fish must also be fish, by definition. Therefore, “being cold blooded” cannot also be a criterion (not that it would work anyway since tuna are warm blooded, BTW, and nobody would argue tuna aren’t fish).
The “living wholly in water” criterion actually works, though: land-fish (e.g. humans) live inside a bag of water that we carry with us.
Nah, phylogenetically speaking, all descendants of fish must also be fish, by definition. Therefore, “being cold blooded” cannot also be a criterion (not that it would work anyway since tuna are warm blooded, BTW, and nobody would argue tuna aren’t fish).
The “living wholly in water” criterion actually works, though: land-fish (e.g. humans) live inside a bag of water that we carry with us.