Diagnostic key to all nominal species of Rhinogobius with longitudinal infraorbital papillae pattern from Fujian Province, PR China

1a Pectoral fin rays modally 19-20, predorsal scales 10-16................................ - R. leavelli (All main basins)

1b Pectoral fin rays no more than 18; predorsal scales no more than 10............................................. 2

2a Cheek with many rounded spots, branchiostegal membrane with several parallel red stripes in male............................................................................................... R. reticulatus (Minjiang basin)

2b Cheek and branchiostegal membrane without such marks..................................................... 3

3a Pore ω1 present, pectoral fin base with reticulated orange pattern in male............ R. xianshuiensis (Mulan river basin)

3b Pore ω1 absent, pectoral fin base without such pattern in male................................................. 4

4a Infraorbital stripe long and well extending downward to rear edge of both jaws or ventral edge of cheek in male......... 5

4b Infraorbital stripe/mark absent or short and not extending ventrally to rear edge of both jaws in male................... 7

5a Cheek with a conspicuous arrow-shape, red to reddish brown infraorbital mark always following by 4 oblique dark stripes in male.......................................................................... R. sagittus (Minjian basin)

5b Cheek with 2-3 oblique dark stripes in male................................................................ 6

6a Pectoral fin rays modally 17; 27 vertebrae; cheek with 3 thin black lines and blackish brown infraorbital stripe in male.............................................................................. R. changtinensis (Hanjiang basin)

6b Pectoral fin rays modally 16; 26 vertebare; cheek with 2 thin brown lines and bright red infraorbital stripe in male.................................................................................. R. rubrolineatus (Minjiang basin)

7a Longitudinal scale rows 25-27; 26 vertebrae; branchiostegal membrane spotless in male........................................................................................... R. longtongyanensis n. sp. (Dongshi river basin)

7b Longitudinal scale rows 28-34; 27-28 vertebrae; branchiostegal membrane with orange to red rounded spots in male...... 8

8a 28 vertebrae; cheek modally with 2 oblique grayish brown stripes..................... R. ponkouensis (Hanjiang basin)

8b 27 vertebrae; cheek stripes 3................................................. R. longyanensis (Julongjiang basin)