Cabezon

Cabezon can grow to pretty substantial sizes, with the largest ever caught growing just short of a meter. Size actually determines their sexual maturity-- males are mature at 13.5in, while females are at 17.5in. A small female can lay over 50,000 eggs in a breeding season, and the males will actually guard those eggs until they hatch! (they will attack you if you get too close to their eggs, as I learned first hand)