Grouper and cod are among the largest of all bony fish and boast equally big mouths. Both species tend to be slow swimmers and are not known for their agility, plus they’re relatively unafraid of divers — all of which make them great models for underwater photography. The Queensland Grouper, or giant grouper, is the largest bony fish found on the Great Barrier Reef. It’s known to grow to massive sizes of more than eight feet long and weigh up to 800 pounds. The Potato Cod is another big fish in the grouper family, growing up to six feet long and weighing more than 200 pounds. Potato Cods get their names from the distinctive brown markings shaped like potatoes that cover their bodies.