APOGONIDAE Apogon leptacanthus, 4.0 cm SL (photo by Ukkrit Satapoomin) Apogon leptacanthus Bleeker, 1856 Longspine Cardinalfish D VI+I, 9; A II, 8; P1 13; LL 24. Body deep, well compressed; lateral line well developed, extending posteriorly to caudal-fin base. Snout moderately pointed. Posterior margin of preopercle serrated. No enlarged caninoid teeth on jaws. Second and third spines of first dorsal fin elongate and filamentous; base of anal fin subequal to base of second dorsal fin in length; caudal fin emarginate. Color: body subtranslucent gray, with a silver line along dorsal profile from base of dorsal fin to caudal fin; belly silvery, tinged with blue; some narrow orange transverse bars, anteroposteriorly sandwiched in blue bars, on midlateral trunk; some similar-colored oblique bars on cheek; fins translucent, except for interradial membranes of dorsal fins with a narrow orange line in each; first dorsal fin sometimes tinged with blue. Size: 5 cm SL. Distribution: Indo-Pacific. Remarks: inhabits coral-reef lagoons; forms aggregations among branching corals. Belonging to subgenus Zoramia, treated as genus by some recent authors.