My thanks to all those who lent a hand with what proved a difficult task, but, the results speak for themselves. What began as a list of the largest fish I could find through patient Internet research for my own interest and purposes, was soon fleshed out by reports of even larger fish that others knew about from their own localities, and their own historical records. As a consequence, it now looks like a realistic view of what canals are capable of producing.
Please keep the reports of remarkable canal specimens coming in. Very old records without proper documentation are so slight that if a new fish comes along very close and with the right credentials, it'll be replaced. The list really needs to be contemporary — canals have changed so much over the last few decades and angler's weighing equipment has so improved in the meantime that records set in the 1950's and 60's are hardly relevant today, even when they're believable.
You can either contact me by mail at firstname.lastname@example.org or leave your report message in comments at the bottom of the page.
Thanks once again, and in advance...