Redear Sunfish are the best way to clean mussels off anything. They have hard movable plates in the throat allow for crushing exoskeletons. They are not harmful to people. These fish also clean out the swimmer's itch in your pond!
Redear Sunfish Facts
Species scientific name: Lepomis microlophus Average life: 3-5 years Largest on Record: 5 pounds, 12 ounces Diet: Mollusks, Snails, Crayfish, Vertebrates, and small Fish.