Microphysogobio, Mori, 1934

Huang, Shih-Pin, Chen, I-Shiung, Zhao, Yahui & Shao, Kwang-Tsao, 2018, Description of A New Species of the Gudgeon Genus Microphysogobio Mori 1934 (Cypriniformes: Cyprinidae) from Guangdong Province, Southern China, Zoological Studies 57 (58), pp. 1-14 : 11-12

A diagnostic key to all valid species of Microphysogobio from southern mainland China, Hainan Island and Taiwan

1a. Medial pad on lower lip undivided.................................... 2

1b. Medial pad on lower lip centrally divided ......................... 4

2a. Lateral-line scales 34; dorsal fin rather long, reach caudal fin base in mature males............................. M. tafangensis

2b. Lateral-line scales more than 36; dorsal fin medium, do not reach caudal fin base in both sexes ................................ 3

3a. Dorsal and caudal fin membranes with two rows of black line; posterior lobe short, 46.8-55.4% of eye diameter ....... .............................................................. M. chenhisenensis

3b. Dorsal and caudal fin membranes without any black lines; posterior lobe long, 79.4-96.3% of eye diameter ................ ....................................................................... M. exilicauda

4a. Two-third ventral region of belly naked ........ M. nudiventris

4b. Ventral region covered with scales .................................. 5

5a. Anal fin rays 3, 5 .............................................................. 6

5b. Anal fin rays 3, 6 .............................................................. 7

6a. Vertebral counts 4 + 30-31; interorbital region with a black crossbar ............................................................. M. zhangi

6b. Vertebral counts 4 + 34; interorbital region without crossbar .................................................................. M. tungtingensis

7a. A “<” shaped black mark on the base of the caudal fin ....... .................................................................. M. xianyouensis

7a. A circular or rectangular mark on the base of the caudal fin .......................................................................................... 8

8a. Lateral-line scales 34; pearl papillae of the posterior lobe reduced, posterior tip smoothed ............... M. microstomus

8b. Lateral-line scales 35-38; pearl papillae of the posterior lobe well-developed, posterior tip free formed ................. 9

9a. No distinct crossbar present on dorsal side ................... 10

9b. Dorsal side with distinct crossbars................................. 11

10a. Pectoral fin rays 1, 12-13; vertebral counts 4 + 33 ............. ................................................................... M. kachekensis

10b. Pectoral fin rays 1, 11; vertebral counts 4 + 32 ................... ............................................................ M. pseudoelongatus

11a. The upper nasal region observed as slightly flatted ........... ....................................................................... M. elongatus

11b. The upper nasal region can be easily observed as recessed ........................................................................ 12

12a. Medial pad heart shaped ............................................... 13

12b. Medial pad square shaped ............................................ 14

13a. Inside papillae lobes covered with 20-26 well-developed pearl-like papillae; snout length 40.2-45.0% of head length ................................................................ M. luhensis n. sp.

13b. Inside papillae lobes covered with 30-41 well-developed pearl-like papillae; snout length 36.6-39.0% of head length ................................................................... M. yunnanensis

14a.Meddle line of the body side with a longitudinal thick greyish black band .......................................... M. fukiensis

14a.Meddle line of the body side with several independent blotches, and do not form a longitudinal band .................... .................................................................... M. kiatingensis