Pearl perch are pretty, silvery coloured fish with large eyes and several brown longitudinal scale rows that are particularly prominent in juveniles. They are so named because they have a very prominent grey/blue coloured bone (the supraclavical bone) that extends out on each side of the upper rear of the operculum. These bones have a thin layer of skin covering them, which when removed reveals the "pearl" in the form of the bone beneath, which is a brilliant pearly white. In contrast, they also have a faint "false eye" spot at the base of the rear of the dorsal fin, while inside the large mouth is often completely black. Another interesting feature is at night some anglers have reported the inside of the mouth to appear slightly luminescent. This might be due to them feeding on salps or other bioluminescent prey at those times. Most of the time pearlies are voracious predators of smaller fish and invertebrates such as squid.