Is that a Fallfish? If so then it's my first one. It took me a while to get any idea of the species of this thing - at first I thought it might be a big rainbow smelt or a sucker of some sort, but it didn't look quite like either one of those. Next suspicion was that I had reeled in someone's pet goldfish that had been set free, but looking at silver-colored goldfish pictures told me it wasn't quite a match for that either.
I had a clean hook on this one so I let it go, but Googling around yielded some results - including a couple Youtube vids - claiming that Fallfish are good eating. Seeing as they're claimed to taste good, I think I'll go back out there and see if I can catch some more. Apparently they reach a decent size as well -- 14-20".