Randall's snapper

Randall's snapper (Randallichthys filamentosus) is a ray-finned fish in the snapper family Lutjanidae, found in the Indo-Pacific. It is the sole species in the genus Randallichthys. The species was first described in 1970 by French ichthyologist Pierre Fourmanoir, who named it Etelis filamentosus based on a specimen from New Caledonia. In 1977, William D. Anderson Jr., Harry T. Kami, and G. David Johnson moved it into its own genus, Randallichthys.

Description

The specific name filamentosus refers to the filament-like extensions on several caudal fin rays of the original specimen, though this trait is not seen in other individuals. The genus name honors American ichthyologist John Ernest Randall, who worked at the Bishop Museum in Honolulu and contributed greatly to the study of Indo-Pacific fishes. This snapper has a fairly elongate body, a short snout, a blunt head, and a flattened area between the eyes. Its lower jaw sticks out, and the vomerine teeth form a chevron shape; there are no teeth on the tongue.

The dorsal fin has 10 spines and 12 soft rays, and the anal fin has 3 spines and 9 soft rays; neither fin has scales at the base. The short pectoral fins do not reach the anus and have 16 to 17 rays. The caudal fin is crescent-shaped, and in young fish the lower lobe rays may be drawn out into filaments. The body is rosy with a yellowish tint on the back.

Distribution and habitat

The dorsal fin is greyish yellow, while the anal and caudal fins are rosy; all fins, including the pelvic fins, have dark to black edges. Maximum total length is 50 cm (20 in), though 40 cm (16 in) is more common. Randall's snapper lives in the eastern Indian Ocean and western Pacific, with records from New Caledonia (the type locality), the Hawaiian Islands, the Cook Islands, the Ryukyu Islands, the Izu Islands, the Ogasawara Islands, Chuuk, Majuro, the Society Islands, and Tonga. In Australia it has been found off Esperance in southern Western Australia, at Scott Reef off northwestern Western Australia, and near Lord Howe Island in the Tasman Sea.

Fisheries

The species is uncommon and likely more widespread than currently known. It inhabits relatively deep water, between 150 and 380 m (490 to 1,250 ft), over rocky bottoms. Commercially, Randall's snapper is taken by hook and line in areas where it occurs, though it is of secondary importance. Its flesh is considered good quality and is sold fresh.