Sailfin snapper

The sailfin snapper (Symphorichthys spilurus), also called the blue-lined sea bream or blue-lined sea perch, is a marine ray-finned fish in the snapper family Lutjanidae. It lives in the Indo-Pacific region and is the only species in its genus.

German-born British ichthyologist Albert Günther first described it in 1874 as Symphorus spilurus, based on a specimen from Palau. In 1967, Australian marine scientist Ian Stafford Ross Munro moved it to its own genus, Symphorichthys, which is one of two genera in the subfamily Paradicichthyinae. The genus name refers to its earlier placement in Symphorus, and the species name spilurus combines the Greek words for "spot" and "tail," referring to the large black blotch on the upper part of the adult's caudal peduncle.

Description

This fish has a deep, laterally compressed body with a rounded head profile, angular forehead, and steep snout. Its mouth reaches to the front edge of the eye, and there is no notch or bump on the preoperculum. The upper jaw has a row of small, flattened teeth, while the lower jaw has about three rows; both jaws also have an outer row of short conical teeth that are slightly larger. There are no vomerine teeth.

The dorsal fin has 10 spines and 14–18 soft rays, and the anal fin has 3 spines and 8–11 soft rays. At least one of the front soft rays in both fins extends beyond the membrane as a long filament. The pectoral fins are long, sometimes reaching past the anus, and have 16 rays. The tail fin is slightly forked.

The fish can grow up to 60 cm (24 in) in total length, but 50 cm (20 in) is more common. Its body is yellowish with blue horizontal stripes along the sides. A large black spot with a pale border sits on the upper caudal peduncle, and there is an orange bar over the eye and another behind the head. Juveniles are pale grey with a wide black stripe bordered in white running from the snout to the tail's rear edge, and their dorsal and anal fin filaments are yellowish.

Distribution and habitat

The sailfin snapper is found in the eastern Indian Ocean and western Pacific Ocean. In the Indian Ocean, it occurs near the Rowley Shoals and Broome, Western Australia. In the Pacific, its range extends east to Tonga and Fiji, north to the Ryukyu Islands, and south to New Caledonia and the Great Barrier Reef. It has also been recorded near the Mentawai Islands off western Sumatra and off the west coast of Thailand.