Lutjanus fulvus, the blacktail snapper, flametail snapper, redmargined seaperch, Waigeu snapper or yellowmargined sea perch, is a species of marine ray-finned fish, a snapper belonging to the family Lutjanidae. It is native to the Indo-West Pacific region. It is an important species for fisheries within its range. Description Lutjanus filvus has a body which has a standard length that is around four times its depth. It has a steeply sloped forehead and a well developed known and notch in the preoperculum. The vomerine teeth are arranged in a crescent shaped patch with no rearwards extension and the tongue is smooth, lacking any teeth. The dorsal fin has 10 spines and 14 soft rays while the anal fin has 3 spines and 8 soft rays, the rear profile of both these fins is rounded. The pectoral fins contain 16 rays and the caudal fin is slightly emarginate. This fish attains a maximum total length of 40 cm (16 in), although 25 cm (9.8 in) is more typical. This species has an overall colour which ranges from orange-brown or brownish to pale yellowish or whitish. The dark reddish to blackish dorsal and caudal fins have a white margin, the anal fin, pectoral and pelvic fins are yellow. The scales have brownish to yellow margins, and there is a yellow patch over the eye. The juveniles are marked with yellowish horizontal stripes and have a black band just underneath the margin of the dorsal fin. Distribution and habitat Lutjanus fulvus has a wide Indo Pacific distribution. It is found from the Gulf of Aden and East Africa south to South Africa through the Indian Ocean but it is absent from the Persian Gulf, east as far as the Marquesas and the Line Islands. It occurs north to southern Japan and south to Australia. In Australia it is found from the Scott Reef of Western Australia, and the Ashmore Reef in the Timor Sea to Sydney, they also occur at Christmas Island and Cocos (Keeling) Islands, as well as Norfolk Island in the Tasman Sea. During the 1950s the Hawaiian Division of Fish and Game released blacktail snappers into Pearl Harbor and off Oahu and it is now found throughout the Hawaiian archipelago but it is nowhere abundant. They have a depth range of 2 to 75 m (6 ft 7 in to 246 ft 1 in) and can be found in lagoons and semi-sheltered seaward reefs. This species was one of the first to re-colonise an area of reef which had been recently dredged off Pohnpei. It shows a preference for sheltered areas where there are deep holes or large boulders. The juveniles are occasionally recorded in shallow mangrove swamps and in the lower reaches of freshwater streams.
