I live in Southern Illinois and have fished here my whole life. I am pretty familiar with the fish species here. However I caught a fish tonight that I could not identify. It was around 15 pounds, 18-20 inches long, dark gray like a catfish, did not have whiskers like a catfish, looked similar to a catfish though, except it had a pitch black mouth? My husband suggested a grennel but I looked at some pictures of it on google and it looked nothing like a grennel. Any ideas?