GOBIIDAE Stigmatogobius sadanundio, NSMT-P 66015, 3.8 cm SL Stigmatogobius sadanundio (Hamilton, 1822) Gray knight goby D VI - I, 7; A I, 8; P1 18 - 19; LR 28; PDS 9. Body relatively deep, compressed. Head slightly compressed; jaws subequal; gill opening not extending anteriorly to a vertical through preopercular margin. Pelvic fins united medially. Scales ctenoid, excepting those on nape, opercle, breast and pectoral fin base cycloid. Sensory canals and pores present on head; transverse rows of sensory papillae on cheek; a pair of short longitudinal sensory-papillae rows just behind chin. Color: body gray with many black dots. Size: 9.0 cm SL. Distribution: Indo-West Pacific. Remarks: found in tidal estuaries and around freshwater area.