Since fish never stop growing, I would say no one knows the maximum size a spake could get. We can only "know" the maximum recorded weight, which for spake appears to be a 27.8 pounded caught by spear fishing http://iusarecords.com/world_record_list.php
Thanks that's what i figured. Though they are "Hatchery specials" they actually are capable of reproducing through an infinite number of generations. That being said it has happened in captivity but not yet recorded in Maine lakes.