Having caught 100's of chain pickerel and a few dozen NP, my best guess is at the same size both species have almost the exact same mouth size. I can tell you from experience, chain pickerel rarely do well in ponds with a healthy LMB population though. Especially if that pond has limited SAV. The LMB do not allow their YOY to survive. I see chain pickerel doing best in ponds where the water is so acidic, LMB either can't live or do very poorly or in other habitat situations where LMB are at a disadvantage.
