Engyprosopon, Gunther, 1862

Amaoka, Kunio & Ho, Hsuan-Ching, 2019, The lefteye flounder family Bothidae (Order Pleuronectiformes) of Taiwan, Zootaxa 4702 (1), pp. 155-215 : 183-184

Key to species of Engyprosopon of Taiwan

1A. Gill rakers without spinules on their inside edges; ocular-side lower jaw 9–13% SL (2.0– 2.5 in HL).................... 2 1B. Gill rakers with spinules on their inside edges; ocular-side lower jaw 13–18% SL (1.5–2.0 in HL)..................... 7 2A. Distal half of caudal fin with a pair of large blackish blotches.................................................. 3 2B. Distal half of caudal fin without blackish blotches........................................................... 5 3A. Gill rakers 16–18 on lower limb................................................................... E. xystrias 3B. Gill rakers 5–11 on lower limb........................................................................... 4

4A. Body ovate, its depth more than half SL; ocular-side pectoral fin rays not filamentous, usually shorter than HL.................................................................................................. E. grandisquama

4B. Body rather elongate, its depth less than half SL; ocular-side pectoral fin rays filamentous, longer than HL... E. multisquama

5A. Interorbital space narrow, 7.8–12.5 in HL; GR 0+6–8; LLs 50–55........................................ E. mogkii

5B. Interorbital space wide, 1.7–3.9 in HL; GR 0–3+9–11; LLs 43–48............................................... 6

6A. Both eyes away from head margin; eyes small, upper eye diameter 5.7–8.6% SL (3.0–4.0 in HL); caudal-peduncle depth 1.7–2.1 in HL; body depth 47.6–54.9% SL (1.8–2.1 in SL).......................................... E. maldivense

6B. Both eyes close to head margin; eyes large, upper eye diameter 9.2–10.0% SL (2.7–2.9 in HL); caudal-peduncle depth 2.2–2.3 in HL; body depth 57.6–59.8% SL (1.7 in SL)................................................... E. brevifrontale

7A. LLs 37–40; ocular-side pelvic fin filamentous in males, 14.1–16.2% SL; fin membrane of ocular-side pelvic fin with many black spots in males......................................................................... E. longipelvis

7B. LLs 46–52; ocular-side pelvic-fin rays not elongate in both sexes, 9.6–14.6% SL; fin membrane of ocular-side pelvic fin without spots in both sexes................................................................................. 8

8A. Eyes separated by a concaved interorbital space in both sexes; eyes large, upper eye diameter 3.0– 3.5 in HL; anterior teeth not enlarged; blind side of body dark in males.................................................... E. mozambiquense

8B. Eyes nearly contiguous, separated by extremely narrow interorbital space, almost filled entirely by a bony ridge in both sexes; eyes small, upper eye diameter 3.8–4.3 in HL; anterior teeth on upper jaw enlarged, canine-like; blind side of body not dark in both sexes.............................................................................. E. parvipectorale