ATHERINIDAE Atherinomorus duodecimalis, 7.1 cm SL (photo by Seishi Kimura) Atherinomorus duodecimalis, 6.1 cm SL (from Iriomote I., Japan; photo by Seishi Kimura) Atherinomorus duodecimalis (Valenciennes, 1835) Tropical Silverside D V-VI + I, 8-11; A I, 11-14 (usually I, 12-13); P1 14-17; LR 35-38; LGR 20-25. Body slender; somewhat compressed. Mouth small, upper jaw just reaching to a vertical through front margin of eye or slightly beyond it; ascending process of premaxilla short and broad; dentary with a tubercle at the posterior end; preopercle notched. Anus situated in front of pelvic-fin tips. Hind margin of lateral scales entire. Color: greenish gray dorsally; a narrow (less than 1 scale width) silvery longitudinal band on side; one or two rows of dark spots usually present below midlateral band. Size: maximum length about 10 cm. Distribution: East Indian Ocean and West Pacific, from Sri Lanka to New Caledonia. Remarks: occurring in beaches and seagrass area.