A wahoo is a species of mackeral. They get very large and fight like crazy.
I love it when you order salmon and you get a filet of something other than salmon. Makes my evening explaining to them salmon meat is an orangish/pinkish color and not white.
Actually - there are white-fleshed wild king salmon! I did not know this until I caught some this year in Alaska and BC, Canada. You can't tell the difference between a white-fleshed and a red-fleshed king salmon until you actually cut them open and see the meat. I have quite a bit of it in my freezer. I also had it this year at a sushi restaurant in Anchorage, AK. It's gooooood. Supposedly only about 1 in 20 wild king salmon have white flesh. It's considered a delicacy and fetches a higher price than wild king salmon with red meat. If you were at a very high-end seafood restaurant then you may have been served wild, white king salmon.
Here's an interesting article on them: White King Salmon