2021 Volume 68 Issue 1 Pages 17-22
Twelve specimens (71.5–89.9 mm standard length) of the genus Lutjanus (Lutjanidae), collected from Ishigaki-jima Island, Ryukyu Archipelago, southern Japan, were identified as Lutjanus biguttatus (Valenciennes in Cuvier and Valenciennes, 1830), being characterized by the following combination of characters: dorsal fin XI, 12; anal fin III, 8; pectoral rays 15–16; body depth 3.5–3.8 in standard length; preorbital depth 10.8– 16.3 in head length; tongue smooth, without patch of fine granular teeth; a dark longitudinal band from snout to caudal fin base; and two white spots above the lateral line. Dentition of the premaxilla and dentary, including several canine-like (one being long and curved) and many small conical teeth, is illustrated. The collected specimens were determined to be juveniles, due to their coloration matching that of juveniles previously described, in addition to their small body size. Although the coloration of L. biguttatus is similar to that of L. vitta during the juvenile stage, the latter species is distinguished by greater body and preorbital depths. The specimens of the former had been caught in a significantly localized area (in ca. 4 m depth) over several days, indicating the likelihood of their having been schooling, as observed in previous studies of the species. Lutjanus biguttatus is distributed in the Indo-western Pacific, from the Maldives to the Solomon Islands, but had not previously been recorded from Japanese waters. The new standard Japanese name “Futahoshi-fuedai”, given in reference to the two white spots above the lateral line in the collected specimens, is proposed.
