Wow. I was always concerned when I was designing Fish Tycoon that fish breeders and enthusiasts might play and potentially be upset at the many 'liberties' that were taken with the breeds, and breeding in general.

Now I'd have to look up the real species names you listed and see the picture to remember who they are in the game. In general though there are not too many dead ends. A better way to describe them would be 'more and less direct routes' to the Magic Fish.

Arthur