Key to the Species of Ventrifossa in Taiwan

1a. Second spinous ray of 1D smooth............................................... 2

1b. Second spinous ray of 1D finely serrated along leading edge......................... 3

2a. Pectoral fin long, 1.3–1.5 into HL; no enlarged spinules on scales along 2D base......................................................................... V. macroptera

2b. Pectoral fin moderate to short, about 1.7 into HL; scales along 2D base with enlarged spinules................................................................. V. sazonovi

3a. Scales extremely small and finely spinulated, scaled surfaces almost velvety when stroked fore and aft; scale rows below 2D origin 9–10 a small tubercular scale at snout tip; suborbital shelf greatly constricted below anterior quarter of orbit.......................... V. misakia

3b. Scales moderate in size with spinules of variable size, skin surface not velvety smooth; scale rows below 2D origin 5–8; no terminal snout scute; suborbital shelf not greatly constricted anteriorly................................................................. 4

4a. Spinules on body scales broad, short, and triangular (V 8–9, usually 8; 1D dusky to clear, without a distinct black blotch)............................................ V. garmani

4b. Spinules on body scales narrowly lanceolate to conical (V 8–10; 1D dusky to blackish, some species with a black blotch)................................................... 5

5a. Body color uniformly brown except swarthy over abdomen (underlain by bluish) and no silvery reflections, suborbital uniformly dark brown, no black shelf; snout rather blunt in lateral view, scarcely protruding beyond mouth.................................... V. saikaiensis

5b. Body color light grayish-brown dorsally, silvery along sides, suborbital with black shelf; snout moderately pointed to rather blunt and prominently to scarcely protruding beyond mouth.. 6

6a. Barbel less than 24% of HL; lateral-line scale rows 43 or less; 1D with prominent black blotch or broad midlateral streak.................................................... 7

6 b. Barbel 25% or more of HL; lateral-line scale rows 45 or more; 1D uniformly dusky or with midlateral black streak....................................................... 8

7a. Rays of V 9 or 10; mesial GR-I 15–17 total, lateral GR-II 14–17 total; length upper jaw usually 43–46% HL; black distal margin anteriorly on A fin................ V. rhipidodorsalis

7b. Rays of V 8 or 9; mesial GR-I 13–15 total, lateral GR-II 12–14 total; length upper jaw 40–43% HL; no black margin on A fin...................................... V. nigrodorsalis

8a. 1D usually uniformly dusky or somewhat darker proximally................. V. divergens

8b. 1D dark or black midlaterally, distally pale or dusky.................... V. longibarbata