HA HA Ha!! I love you BadCoyotee! That's funny.
So, FYI... I just got back from fishing with Tbubb and PikeNColorado at St. Vrain. They did better than I did... and the mosquitoes out did us all! LOL
That is a roundtail chub.
Okay... now this is how I can tell.
1) It has red on it... pikeminnow don't have red... they might have golden appearance, but not red. So pikeminnow is out by coloration.
2) The mouth is sub-terminal, meaning it not all the way on the end. Best way to illustrate this, imagine this fish running into a plate of glass. If the upper lip hits glass first, you have a terminal fish. If the snout, or nose, hits first, you have a sub-terminal mouth. The mouth also has an oblique angle to it, where as the pikeminnow's mouth is almost parallel to the bottom of the head. In addition, the mouth is not big enough to be a pikeminnow. This would be a measurement that most wouldn't have access to... so please use the other features.
3) The nuchal hump, think dowager's hump, is basically absent and is too streamline to be bonytail or humpback chub. In species, the progression of the nuchal hump would be roundtail (none), bonytail (obvious - but not huge), and humpback (so obvious - you'd think how is this fish swimming!).
4) The presence of large scales is also characteristic of roundtail. Bonytail will have fine scales and humpback will appear to have none (but they do have them).
5) The tail, or caudal peduncle, the area right before the tail is too thick to be bonytail or humpback. If it was a bonytail, it should about as thin and round like a normal permanent marksalot, not the king sized one.
I hope this helps. That is a nice roundtail! I love catching them... fight hard and really cool. Toothless and a native minnow.