In George Orwell’s ‘Coming Up For Air’, the principal character, George Bowling, falls into a deep reminiscence about his boyhood fishing exploits.
In one he discovers a small pond that, over time, had become detached from a larger one. In the process, some of the fish got cut off, marooned in the small pond.
Left alone, with no competition for food and no danger from predators (including schoolboys fishing), these fish grew to monstrous proportions. Is this why Small Ponds are associated with Big Fish?
George Bowling would daily visit one such fish, a massive carp, in the small detached pond behind Binfield Hall.
Billy's Scrapbook 