GOBIIDAE Amblygobius semicinctus, 4.6 cm SL (photo by Ukkrit Satapoomin) Amblygobius semicinctus (Bennett, 1833) Half-barred Goby D VI + I, 14-15; A I, 14-15; P1 19-20; LR 54-57; PDS 22-25. Body moderately elongate and compressed. Head slightly compressed; snout rounded, protruding beyond jaws; gill opening not extending anteriorly to a vertical line through posterior margin of preopercle; tongue rounded or near truncate. Middle spines of first dorsal fin elongate and filamentous; pelvic fins united medially; frenum present. Scales on body ctenoid, exclusive of occipital region, nape, pectoral-fin base, belly and breast with cycloid scales; dorsal part of operculum with cycloid scales, other areas of head naked. Sensory canals and pores present on head; a series of short transverse rows of sensory papillae below eye; a pair of short longitudinal sensorypapillae rows just behind chin. Color: complex pattern of narrow dusky bars and indistinct horizontal dashed lines; many small close-set orange spots on top of head; irregular shaped sky blue spots on cheek and operclum; narrow sky blue bars on side of belly; some small black spot on caudal fin, anterior one of them closing caudal-fin base. Size: 11.0 cm SL. Distribution: Indian Ocean, Andaman Sea, eastward to Bali Island of Indoensia. Remarks: found in protected bays, lagoons and estuaries.