Microphysogobio Mori, 1934

Sun, Zhi-Xian, Tang, Wen-Qiao & Zhao, Ya-Hui, 2025, Generic revision on the Biwia – Microphysogobio complex (Cypriniformes, Gobionidae) with descriptions of three new genera, Zoosystematics and Evolution 101 (4), pp. 2013-2037 : 2013-2037

Microphysogobio Mori, 1934

Fig. 7

Microphysogobio Mori, 1934: 39. Type species: Microphysogobio hsinglungshanensis Mori, 1934.

Rostrogobio Taranetz, 1937: 114. Type species: Rostrogobio amurensis Taranetz, 1937.

Diagnosis.

This genus can be distinguished from the other genera within the Pseudogobionini by the combination of the characters: (1) mouth arc-shaped and inferior; (2) central portion of the anterior papillae usually larger than lateral portion of anterior papillae on upper lip, in one row; (3) lower lip forming two lateral lobes and a medial pad, without anterior fold; (4) lateral lobes on lower lip not in contact with each other posteriorly from medial pad; (5) medial pad on lower lip heart-shaped or inverted trapezoid-shaped, sometimes bisected or grooved; (6) upper jaw wide, the horny margin width larger than half mouth width; (7) lower jaw exposed; (8) barbel in one pair; (9) midventral region of body scaleless or sometime covered with scales; (10) pharyngeal teeth in one row; (11) anterior chamber of the air bladder enclosed in thick fibrous capsule; (12) posterior chamber relatively small, length smaller than half eye diameter, smaller than anterior chamber length, thin.

Description.

Body elongated, abdomen rounded; caudal peduncle short, compressed laterally. Mouth arc-shaped and inferior; barbel one pair; lips thick, with developed papillae; central portion of the anterior papillae usually larger than lateral portion of anterior papillae on upper lip, in one row, lateral portion of anterior papillae in several rows; lower lip forming two lateral lobes and one medial pad, without anterior fold; two lateral lobes on lower lip not in contact with each other posteriorly from medial pad, laterally connected with upper lip anterior papillae around mouth corners; medial pad on lower lip heart-shaped or inverted-trapezoidshaped, sometimes bisected or grooved. Upper and lower jaws with horny sheathed edge; upper jaw wide, horny margin width larger than half mouth width; lower jaw exposed (Fig. 3 B ). Body covered with moderately large cycloid scales. Thoracic region scaleless, mid-ventral region scaleless or covered with scales. Anus positioned in anterior one-third of pelvic-fin insertion and anal-fin base. Lateral line complete, almost straight. Lateral-line scales usually 35–40; scales above lateral line 3.5–5; scales below lateral line usually 1.5–2; predorsal scales 9–13; circumpeduncular scales 12. Distal margin of expanded dorsal fin steep sloped, usually slightly concave, with three unbranched and seven branched rays, pectoral fin with one unbranched and 10–12 branched rays, pelvic fin usually with one unbranched and six or seven branched rays, anal fin with three unbranched and six branched rays; caudal fin forked, with one simple ray and nine branched rays on upper lobe and eight branched rays and one simple ray on lower lobe, lobes pointed. Pharyngeal teeth “ 5–5 ” in one row. Air bladder small, possessing two chambers; anterior chamber flat rounded, enclosed in a thick fibrous capsule; posterior chamber small, length shorter than anterior chamber length, less than half eye diameter, thin. Intestine long, complicated, usually coiling.

Distribution.

This genus exhibits a relatively extensive distribution. The northernmost boundary is the Heilongjiang River (Amur River) between northeastern China and Far East Russia. The southernmost boundary is the coastal rivers in Fujian Province and northern coastal rivers in Taiwan Province, China. The westernmost boundary is upper reaches of the Yangtze River in Sichuan Province, China, while the easternmost distribution is the west and south coastal rivers of the Korean Peninsula (Fig. 5 C ).

Etymology.

“ Micro- ” comes from the Greek word “ mikrós ”, meaning small; “ physo- ” comes from the Greek word “ phýsa ”, meaning bladder. The generic name refers to the reduced swim bladder of the species in this genus. The generic name in Chinese is “ 小鳔鮈 ” 属, and the Chinese Pinyin name is “ Xiǎo Biào Jū ” Shǔ.

Species included.

Microphysogobio brevirostris (Günther, 1868) .

Microphysogobio chinssuensis (Nichols, 1926) .

Microphysogobio yaluensis (Mori, 1928) .

Microphysogobio hsinglungshanensis Mori, 1934 (type species).

Microphysogobio koreensis Mori, 1935 .

Microphysogobio longidorsalis Mori, 1935 .

Microphysogobio amurensis ( Taranetz, 1937) .

Microphysogobio alticorpus Bănărescu & Nalbant, 1968 .

Microphysogobio anudarini Holcík & Pivnicka, 1969 .

Microphysogobio springeri ( Bănărescu & Nalbant, 1973) , comb. nov.

Microphysogobio nudiventris (Lo, Yao & Chen, 1977) .

Microphysogobio linghensis Xie, 1986 .

Microphysogobio liaohensis (Qin, 1987) .

Microphysogobio rapidus Chae & Yang, 1999 .

Microphysogobio jeoni Kim & Yang, 1999 .

Microphysogobio wulonghensis Xing, Zhao, Tang & Zhang, 2011 .

Microphysogobio “ nudiventris ” Jiang, Gao & Zhang, 2012.

Microphysogobio xianyouensis Huang, Chen & Shao, 2016 .

Microphysogobio oujiangensis Sun & Zhao, 2022 .

Remarks.

This study classifies Platysmacheilus nudiventris as a Microphysogobio species. However, another Microphysogobio species described by Jiang et al. (2012) also used the same specific name. Since P. nudiventris preoccupied this species name in 1977, the species described by Jiang et al. (2012) requires renaming in the future taxonomic study.

Figures

Figure 3. Lip papillae patterns of the type species of seven genera within the Biwia – Microphysogobio complex, with a diagrammatic illustration showing the structures. A. Biwia zezera, KUN-P 040282; B. Microphysogobio hsinglungshanensis, ASIZB 240788; C. Huigobio chenhsienensis, SHOU 20231209015; D. Oriengobio fukiensis, ASIZB 220659; E. Mesophysogobio kachekensis, ASIZB 69768; F. Platysmacheilus exiguus, ASIZB 220879; G. Crossocheilogobio tafangensis, ASIZB 60212; H. diagrammatic illustration based on Microphysogobio chinssuensis. CPAP = central portion of anterior papillae; LPAP = lateral portion of anterior papillae; MP = medial pad; LL = lateral lobe; BB = barbel; UJ = upper jaw; LJ = lower jaw. The photo of Biwia zezera is provided by Seigo Kawase; the other photos and illustration were made by Zhi-Xian Sun.

Figure 5. The distributions of the Biwia – Microphysogobio complex and seven genera. A. The complex; B. Biwia; C. Microphysogobio; D. Huigobio; E. Platysmacheilus; F. Crossocheilogobio gen. nov.; G. Oriengobio gen. nov.; H. Mesophysogobio gen. nov.

Figure 7. The general view of Microphysogobio hsinglungshanensis, the type species of the genus Microphysogobio, ASIZB 240788, 51.7 mm SL, collected from the Liuhe River in the Luanhe River Basin, Xinglong County, Hebei Province, China. A. Lateral view; B. Dorsal view; C. Ventral view. Scale bar: 10 mm. Photographed by Zhi-Xian Sun.