RNJ -- I don't know. I would guess that chain pickerel would be similar to northern pike, but I don't know what minor differences they might have in gape width? Would a pike-like fish that has a smaller maximum size have a smaller gape at a given length than the northern pike? I don't know. I've only caught a couple of chain pickerel in my life, so haven't looked at many. I did a quick search on Google Scholar for chain pickerel and gape, and didn't get any useful papers returned. That does NOT mean there is no work out there, just that the quick search didn't easily turn up such work. So, my best guess is that chain pickerel and pike should at least be somewhat similar, but I'm unsure if there are minor differences between the two species.
