ACANTHURIDAE Naso thynnoides (photo by Niphon Phongsuwan) Naso thynnoides (Cuvier, 1829) Singlespine Unicornfish D IV-V, 28-30; A II, 28-30; P1 16-18. Body moderately deep, 2.8-3.2 in SL. Dorsal profile of head convex without protuberance. Caudal fin emarginated. Caudal peduncle with 1 bony plate, the keel small and approximately semicircular. Color: body gray, paler ventrally, with about 30 narrow, dark bluish gray bars; irregular dark bluish gray spots on head; a broad, diffuse yellow stripe on side of body; peduncular plate and keel dusky; caudal fin bluish gray. Size: attaining to ca. 29 cm. Distribution: Indo-West Pacific. Remarks: found in the protected waters of lagoons and in exposed outerreef areas, from the shallows to least 40 m, generally more than 10 m.