Blue-ringed Angelfish - Pomacanthus annularis - Gliding through a Shaded Reef

A Blue-ringed Angelfish glides through a shaded reef area outside Pattaya, Thailand, its vivid electric-blue lines contrasting with the darker underwater surroundings.

The Blue-ringed Angelfish (Pomacanthus annularis) has a deep, strongly compressed body with extended dorsal and anal fins and a characteristic spine on the gill cover. Adults are golden-brown to olive or orange-brown, crossed by a series of curved electric-blue lines that sweep backwards across the body. Additional blue markings run across the face, while a distinctive blue ring lies behind and slightly above the gill cover. The tail is pale to whitish and may carry a yellow margin. This large marine angelfish inhabits tropical coastal reefs throughout the Indo-West Pacific, including Thailand, from shallow water to about 60 metres depth. Adults may occur alone or in pairs and often use caves and sheltered reef areas. They feed mainly on sponges and tunicates and can reach approximately 45 centimetres in total length. This photograph shows an adult moving through a darker reef habitat outside Pattaya, where its brilliant blue markings remain particularly striking.