In this video from who we believe is a man called Carl Willis, we see what the radiation has done to these catfish.
“Meet the monster catfish living in the channel that once brought cooling water to the ChNPP condensers. Radioactivity has indeed made these fish abnormally large, by effectively taking their most significant natural predator–the human–out of the food chain. The fish have become a popular attraction at Chernobyl. They have learned to congregate under the railroad bridge just east of ABK-1 in anticipation of food thrown to them by station employees and visitors, as we are doing here.”