POLYNEMIDAE Polydactylus siamensis, 15.4 cm SL (photo by Ukkrit Satapoomin) Polydactylus siamensis Motomura, Iwatsuki and Yoshino, 2001 Largemouth Striped Threadfin D VIII+I, 12-13, 9; A III, 11; P1 15+5 filaments; P2 I, 5; LLp 54-58; GR 22-24. Body moderately elongate, compressed. Posterior margin of maxilla extending slightly beyond a vertical through posterior margin of adipose eyelid. Upper jaw length 5.9-6.2 in SL. Lip on lower jaw well-developed, dentary teeth restricted to dorsal surface; teeth villiform in broad bands on vomer, palatines and ectopterygoids. Longest pectoral filament reaching to or extending beyond posterior tip of pelvic fin. Swimbladder absent. Color: 7 or 8 prominent longitudinal dark stripes along scale rows above lateral line, 7 to 9 faint stripes below. Size: maximum length 25 cm SL. Distribution: currently known only from Gulf of Thailand (very rare) and the Andaman Sea (relatively common). Remarks: occurs on sandy or muddy bottoms.