Key to the species of genus Liopropoma in Taiwan:

1. Dorsal fin divided into two, separated by a clear gape........................................................ 2 - Dorsal fin continuous (middle portion connected by membranes)............................................... 3 2. Body with 4–8 dark longitudinal stripes............................................................ L. susumi - Body without dark longitudinal stripes........................................................... L. pallidum

3. Posterior margin of caudal fin blackish; tubular anterior nostril opening midway between snout tip and posterior nostril.... 4 - Posterior margin of caudal fin not blackish; tubular anterior nostril opening more anteriorly positioned on snout.......... 5

4. Pectoral-fin long, 26.9–29.1%; body uniformly bright red when fresh................................. L. erythraeum - Pectoral-fin short, 23.4–23.9%; body red, but dorsally yellow when fresh............................ L. dorsoluteum

5. Dorsal-fin soft rays 13–14; anal-fin soft rays 10–11; body and fins pink or red; a bright red mid lateral stripe.. L. japonicum - Dorsal-fin soft rays 12 (except for 13 in L. latifasciatum); anal-fin soft rays 8–9; body and fins mainly yellow........... 6

6. Dorsal-fin soft rays 13; anal-fin soft rays 9; a broad dark brown or brownish-yellow stripe along upper body to upper caudal fin base, lower edge of stripe not overlapping straight peduncular portion of lateral line.................... L. latifasciatum

- Dorsal-fin soft rays 12; anal-fin soft rays 8; a broad dark brown or brownish-yellow stripe along mid-body to middle of caudal fin base, lower edge of stripe overlapping straight peduncular portion of lateral line or mid-body stripe diffuse........... 7

7. Numerous small spots on upper half of body............................................................... 8 - Body without spots................................................................................... 9

8. Lateral-line scales 61–66; red spots on upper half of body........................................... L. maculatum - Lateral-line scales 46–49; black or dark brown spots on upper half of body............................. L. lunulatum

9. Caudal-fin concavity depth 8.5–9.9% SL; a dark mid-lateral and yellow abdominal stripe when fresh (evident as faint dark pigments when preserved).................................................................... L. lemniscatum

- Caudal-fin concavity depth 10.1–11.0% SL; a yellow stripe anteriorly on body, becoming diffuse centrally and absent on abdomen when fresh (no dark pigments on body when preserved)........................................... L. aragai