OSTRACIIDAE Tetrosomus gibbosus, 6.2 cm SL (photo by Ukkrit Satapoomin) Tetrosomus gibbosus (Linnaeus, 1758) Hampback Boxfish D 9; A 9-10 (usually 9); P1 10-11. Body triangular in cross section. Three sharp spines on longitudinal median ridge on back; 4 or 5 smaller spines on ventrolateral ridge. A small spine on ridge above eye. Color: light brown to yellowish gray. Size: maximum 30 cm. Distribution: widely distributed in tropical Indo-Pacific, from East Africa eastward to northern Australia, north to southern Japan. Remarks: occurring in seagrass beds or algal flats and sandy bottoms to depths of 50 m.