Serranus tigrinus has a laterally compressed elongate body with a pointed snout which is shorter than the diameter of the eye. It has 3 clearly visible spines on the gill cover, the middle spine being straight. The margins of the preopercle are regularly serrated but there are no spines at its angle. The dorsal fin has 10 spines and 12 soft rays while the anal fin contains 3 spines and 7 soft rays. The caudal fin is slightly concave. This species has a black and white mottle pattern on its back and a yellow and black mottled pattern on the lower body. A black strip runs from the snout through the eye, and the chin and throat have large black blotches on a white background. There are 8 vertical black bars, 2 on the nape and 6 on the body. The caudal fin has a black bar at its base and the membrane is marked with black spots. The dorsal fin has two lines of black spots along it while the base of the anal fin has a single line of black spots. The maximum published total length is 29 centimetres (11 in). Serranus tigrinus is a species of the western Atlantic Ocean where it is found throughout the Caribbean from southern Florida to Trinidad and Tobago, including the mainland coast from the Yucatan Peninsula of Mexico to Venezuela.
