ACANTHURIDAE Acanthurus tennenti (photo by Ukkrit Satapoomin) Acanthurus tennenti Günther,1861 Double-band Surgeonfish D IX, 23-24; A III, 22-23; P1 16; GR 23-25. Body deep, 2.0-2.4 in SL. Teeth fixed, denticulate on all of margin, with expanded incurved tips; adults with about 20 upper and 22 lower teeth. Caudal fin emarginate, the caudal concavity 5-10 in SL. Caudal peduncle with 1 folding spine. Color: body brown with 2 short black bands, one passing posteriorly from upper end of gill opening and the other above and parallel to it; caudal fin with a white border, very broad posteriorly in central part of fin; socket of caudal spine broadly bordered in black with an outer blue margin. Size: attaining to 31 cm. Distribution: mainly Indian Ocean, ranges east to Bali, Indonesia. Remarks: observed in coral reef areas at depths of 1-20 m.