Key to species of Nemipterus from Taiwan

1a. Anal-fin rays III, 8................................................................. N. virgatus (W. Pacific)

1b. Anal-fin rays III, 7................................................................................... 2

2a First two dorsal-fin spines close together, almost fused, produced to form a very long filament; upper caudal lobe with long filamentous extension...................................... N. nematophorus (Eastern Indian Ocean and W. Pacific)

2b. First two dorsal-fin spines separated by a membrane, not produced into a long filament, and shorter than the following spines................................................................................................... 3

3a. Membranes between dorsal-fin spines deeply incised................................... N. peronii (Indo-W. Pacific)

3b. Membranes between dorsal-fin spines continuous or only slightly incised........................................ 4

4a. Pelvic fins very long, reaching to or beyond origin of anal fin................................................. 5

4b. Pelvic fins short or moderately long, not reaching to origin of anal fin.......................................... 6

5a Scales below lateral-line in ascending rows anteriorly; dorsal fin pale yellow, with a yellow margin and pale mauve submar- ginal stripe; distinctive broad, bicoloured submedial stripe (yellow above, orange below) along dorsal fin.................................................................................................. N. aurora (W. Pacific)

5b Scales below lateral-line in more or less horizontal rows anteriorly; dorsal fin pale pink, with broad yellow margin, edged below by red; greyish mauve submarginal stripe on posterior half of dorsal fin..... N. sugillatus n. sp. (Indonesia, Taiwan)

6a. Pectoral fins very long, reaching to or beyond level of origin of anal fin.................. N. japonicus (Indo-W. Pacific)

6b. Pectoral fins short or moderately long, not reaching to level of origin of anal fin.................................. 7

7a. Upper lobe of caudal fin pointed or rounded, not produced................................................... 8

7b. Upper lobe of caudal fin produced to an elongate point, falcate or with a filamentous extension...................... 9

8a. Line drawn up from posterior edge of suborbital reaching dorsal profile at about origin of dorsal fin; pectoral fins reaching to or short of anus................................................................ N. furcosus (Indo-W. Pacific)

8b. Line drawn up from posterior edge of suborbital reaching dorsal profile about 2–6 scales before origin of dorsal fin; pectoral fins reaching to beyond level of anus....................................... N. hexodon (Andaman Sea, W. Pacific)

9a. Upper lobe of caudal fin produced to an elongate point; dorsal fin elevated, first dorsal spine long, 1.1–1.4 in length of longest dorsal spine.............................................. N. thosaporni (W. Pacific, southern Japan to Indonesia)

9b. Upper lobe of caudal fin falcate or extended into a short or long filament; dorsal fin not notably elevated, first dorsal spine short, 1.3–2.9 in length of longest spine................................................................. 10

10a. Body elongate, depth 3.8–4.6 in SL; upper lobe of caudal fin extended into a short filament; eye tangent to or above a line from tip of snout to upper base of pectoral fin............................................. N. zysron (Indo-W. Pacific)

10b. Body moderately deep, depth 3.2–4.0 in SL; upper lobe of caudal fin falcate, ribbon-like; eye tangent to or below a line from tip of snout to upper base of pectoral fin............................................... N. bathybius (W. Pacific)