Two new freshwater gobiid species of Rhinogobius Gill, 1859 (Teleostei: Gobiidae) from Taiwan Author Chen, I-Shiung Institute of Marine Biology, National Taiwan Ocean University, Keelung, 202301, Taiwan, R. O. C. & Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung, 202301, Taiwan, R. O. C. Author Yeh, Ming-Fon Taiwan Biodiversity Research Institute, 1 Min-Sheng E. Road, Jiji, Nantou 552, Taiwan, R. O. C. text Zootaxa 2024 2024-12-10 5550 1 333 353 https://doi.org/10.11646/zootaxa.5550.1.34 journal article 10.11646/zootaxa.5550.1.34 1175-5326 14389553 A1EF2621-F0E7-4C7C-B175-966FBECCE621 Diagnostic key of 13 nominal species of Rhinogobius Gill, 1859 from Taiwan 1a Infraorbital papillae row a and c with transverse extension; predorsal region with large ctenoid scales; pelvic fin large and elliptical............................................................................. R. similis Gill, 1859 1b Infraorbital papillae row a and c as typically linear, longitudinal pattern; predorsal region naked or merely with small cycloid scales; pelvic fin small and roundedf...................................................................... 2 2a Vertebral count 27; no preopercular canal.................................................................. 3 2b Vertebral count 26; preopercular canal present.............................................................. 6 3a Second dorsal fin modally I/9; anal fin modally I/8; snout with two broad, lateral stripes (posterior one orange in male).......................................................................... R. yangminshanensis Chen et al. , 2022 3b Second dorsal fin modally I/8; anal fin modally I/7; snout with one lateral orange to brownish red, brown curve turning vertically........................................................................................... 4 4a Pectoral fin rays modally 17; longitudinal scale series modally 33......................... R. baborinisanensis n. sp. 4b Pectoral fin rays modally less than 17; longitudinal scale series modally 28–29.................................... 5 5a Pectoral fin rays modally 15; predorsal scale series usually 14–15; the black blotch on first dorsal fin large and its height about 1/2 length of second dorsal spine in male............................................. R. macromaculatus n. sp. 5b Pectoral fin rays modally 16; predorsal scale series modally 11; the black blotch on first dorsal fin small and its height about 1/4 length of second dorsal spine in male................................... R. rubromaculatus Lee & Chang, 1996 6a Scale rows between origin of first dorsal fin and pectoral fin 6–8; abdomen median naked before anus........................................................................................ R. maculafasciatus Chen & Shao, 1996 6b Scale rows between origin of first dorsal fin and pectoral fin 9–15; abdomen median with small cycloid scales before anus..... 7 7a Second dorsal fin and caudal fin pale......................................................................... 8 7b Second dorsal fin and caudal fin with some rows of spots..................................................... 9 8a Row b with 7–8 papillae; lateral body uniformly unmarked............................. R. candidianus (Regan, 1908) 8b Row b with 12–13 papillae; lateral midline of trunk with 5–6 deep gray bloches..... R. nantaiensis Aonuma & Chen, 1996 9a Cheek with brownish red wavy lines............................................... R. formosanus Oshima, 1919 9b Cheek with orange or brown, blackish brown spots......................................................... 10 10a Lateral midline of trunk with vertical deep brown or grayish brown blotches; caudal fin base with a blackish brown curve..................................................................................................... 11 10b Lateral midline of trunk in lacking conspicuous blotches; caudal fin with two well separate deep brown bars........... 12 11a Pectoral fin rays 21–23; longitudinal scale rows 36–39; prepelvic area naked............ R. gigas Aonuma & Chen, 1996 11b Pectoral fin rays 19–21; longitudinal scale rows 32–35; prepelvic area with small cycloid scales.......................................................................................... R. lanyuensis Chen, Miller & Fang, 1998 12a Pectoral fin rays modally 18; median fin black; cheek with 100–120 very tiny black spots...................................................................................................... R. delicatus Chen & Shao, 1996 12b Pectoral fin rays always 19–20; median fin pale brown; cheek with 15–30 red or brownish red small spots.................................................................................... R. henchuenensis Chen & Shao, 1996