Polysteganus coeruleopunctatus Has a deep body which has a depth that fits into its standard length 2.2 or 2.3 times and is greater than the length of the head. The dorsal profile of the head is smooth with a small hump in front of the eyes. The
pectoral fins are longer than the head. The
dorsal fin is supported by 12 spines and 10 soft rays while there are 3 spines and 8 soft rays supporting the
anal fin. As is typical for
Polysteganus the
canine-like teeth in the upper jaw are not well developed. The upper body is rosy in colour, the lower body is silvery. The scales on the upper body each have a blue spot and these form blue lines along the scale rows. This species has a maximum published total length of , but is more typical. ==Distribution and habitat==