yeah, I've wondered about that one myself. In regard to species classification though, it seems like herps and fish are complicated. Trout and Salmon as well as Kingsnakes, Milksnakes, Ratsnakes, Pinesnakes, etc are capbable of producing fertile offspring from cross-genera hybridizations. Most egg-laying colubrid snakes in NA can hybridize with fertile offspring. It's really crazy and I don't pretend to understand it for a minute. While I don't know much about the genetics behind the snakes, trout and salmon in separate genera with different numbers of chromosomes can produce fertile hybrids as well. That's just not right...