The Rudd is one of the smaller fish at Croome and would be the sort of fish the herons would eat. They are usually around 4-8 inches. They are relatively easy to spot in the murky water, as they are silver/gold, with bright red fins. The Roach is a similar fish, but they are more silver rather than gold and the fins are orange rather than red. You can also tell the difference by the position of fins, the Rudd's dorsal fin (on the back) is set back from the pelvic fins below.