Thats weird i been doing some searching on my hard drive last summer i caught a smaller pike "Pike, river pike, grass pike, jack, jackfish, eastern pickerel, chainsides, mud pickerel lots of names eh!"on the Island and had similar patterns and was more of a gold and brown color, I am baffled i did some on-line research and came up with a nice drawing:
also found a article which posts it was introduced to Lake Ontario and Lake Erie:
North America: Nova Scotia, Canada (introduced) to southern Florida, USA; Gulf coast west to Sabine Lake drainage in Louisiana, USA; Mississippi River basin north to Kentucky and Missouri, USA. Introduced to Lakes Ontario and Erie drainages and elsewhere:
http://www.fishbase.org/summary/speciessummary.php?id=2712
So i think the chance of getting the odd Chain pike is pretty low but if caught the angler mite think it's just a small pike "like myself" and released and forgotten.