Microphysogobio tungtingensis (Nichols, 1926)

Sun, Zhi-Xian, Tang, Wen-Qiao & Zhao, Ya-Hui, 2024, Redescription of Microphysogobio tungtingensis (Nichols, 1926) with the description of a new species of the genus (Cypriniformes, Gobionidae) from southern China, ZooKeys 1214, pp. 161-186 : 161-186

Microphysogobio tungtingensis (Nichols, 1926)

Figs 1 , 2 ; Table 2

Pseudogobio tungtingensis Nichols, 1926: 4 (original description); Nichols (1943): 180.

Microphysogobio tungtingensis : Bănărescu and Nalbant (1966): 201 (partim: Huping on lake Tungting, Hunan).

Abbottina elongata : Yao and Yang in Luo et al. (1977): 524.

Microphysogobio elongatus : Yue (1998): 362 (partim: Guilin, Liujiang, and Ningming in Guangxi); Zhang and Zhao (2016): 74; Xiao and Lan (2023): 154.

Microphysogobio kiatingensis : Xiao and Lan (2023): 152.

Material examined.

Holotype. • AMNH 8447 , 51.3 mm standard length (SL); Huping (= Hubin), Tungting Lake (= Lake Dongting), Hunan (= Hunan Province), China; collected by Clifford H. Pope; 1921.

Additional material examined.

• ASIZB 240436–44 , 9 specimens, 50.8–73.0 mm SL; Changsha City, Hunan Province, from the confluence of the Jinjianghe River and the Xiangjiang River (28.13403751 ° N, 112.95238278 ° E, 29 m a. s. l.); collected by Mr. Tao Jiang, 22 October 2022 • ASIZB 240430–2 , 3 specimens, 58.9–69.4 mm SL; Ximaowu Village, Yisuhe Township, Xiangtan County, Xiangtan City, Hunan Province, from the Juanshui River (27.73808121 ° N, 112.88006622 ° E, 36 m a. s. l.); collected by Mr. Tao Jiang; 7 December 2022 • ASIZB 240386–92 , 7 specimens, 70.9–84.7 mm SL; Longxia Village, Hukou Township, Chaling County, Zhuzhou City, Hunan Province, from the Mishui River (26.56112501 ° N, 113.60761060 ° E, 144 m a. s. l.); collected by Zhixian Sun; 1 October 2020 • ASIZB 240395–404 , 10 specimens, 54.6–74.5 mm SL; Yuelu District, Changsha City, Hunan Province, from the Jinjianghe River (28.12234231 ° N, 112.90897867 ° E, 29 m a. s. l.); collected by Mr. Tao Jiang; 8–17 June 2023 • ASIZB 240445–9 , 5 specimens, 43.1–59.4 mm SL; Yuelu District, Changsha City, Hunan Province, from the Jinjianghe River (28.12234231 ° N, 112.90897867 ° E, 29 m a. s. l.); collected by Mr. Tao Jiang; 25 November 2023 • IHB 587820 , 1 specimen, 65.9 mm SL; Guilin City, Guangxi Zhuang Autonomous Region, from the Lijiang River ; July 1958 • IHB 587249 , 587254 , 587876 , 3 specimens, 74.3–79.0 mm SL; Liujiang District, Liuzhou City, Guangxi Zhuang Autonomous Region, from the Liujiang River ; July 1958 • IHB 587915 , 1 specimen, 64.2 mm SL; Ningming County, Chongzuo City, Guangxi Zhuang Autonomous Region, from the Mingjiang River • ASIZB 240340–5 , 240461–77 , 23 specimens, 61.3–75.3 mm SL; Shangtai Village, Yongfu Township, Yongfu County, Guilin City, Guangxi Zhuang Autonomous Region, from the Xihe River (25.01610083 ° N, 109.98018869 ° E, 140 m a. s. l.); collected by Zhixian Sun, Chen Tian and Dong Sheng; 2 January 2024 • ASIZB 185300–5 , 6 specimens, 59.4–81.4 mm SL; Jiangzhou District, Chongzuo City, Guangxi Zhuang Autonomous Region, from the Zuojiang River ; 14 March 2003 • ASIZB 185204–5 , 2 specimens, 59.4–61.3 mm SL; Sanjiang Dong Autonomous County, Liuzhou City, Guangxi Zhuang Autonomous Region, from the Liujiang River ; 8 March 2003 • ASIZB 240393–4 , 2 specimens, 72.9–74.9 mm SL; Yangshuo County, Guilin City, Guangxi Zhuang Autonomous Region, from the Lijiang River ; collected by Zhixian Sun; 8 July 2019 • ASIZB 240427–8 , 2 specimens, 54.6–67.9 mm SL; Pingle County, Guilin City, Guangxi Zhuang Autonomous Region, from the Lijiang River ; collected by Zhixian Sun; 16 January 2020 • ASIZB 240426 , 1 specimen, 72.3 mm SL; Pingle County, Guilin City, Guangxi Zhuang Autonomous Region, from the Lijiang River ; collected by Zhixian Sun; 10 January 2021 .

Diagnosis.

Posterior chamber of air-bladder small, elongated oval shaped, length 9.2 % – 11.8 % of head length, and 30.4 % – 34.9 % of eye diameter; upper jaw cutting-edge narrow, width less than half mouth width; lateral-line scales 36–39 (mode and mean 37); circumpeduncular scales 12; branched anal-fin rays 6; midventral region of body scaleless only before pectoral-fin base end.

Redescription.

Body elongated, thoracic region flattened, abdomen rounded, caudal peduncle short, compressed laterally. Dorsal body profile rising from nostrils to dorsal-fin origin, dropping along dorsal-fin base, then gradually sloping to caudal-fin base. Maximum body depth at dorsal-fin origin, body depth 14.7 % – 20.1 % of standard length. Head elongated, length larger than body depth; snout blunt, with concavity on top of snout before nostrils; eye diameter 29.3 % – 38.9 % of head length, located at dorsal half of head; interorbital region flattened, width smaller than eye diameter (28.6 % – 50.5 % of eye diameter). Anus positioned at anterior one-third of distance from pelvic-fin insertion to anal-fin origin.

Mouth horseshoe-shaped and inferior, with one pair of maxillary barbels rooted at extremity of upper lip, barbel length shorter than eye diameter (35.2 % – 71.7 % of eye diameter); upper and lower jaws with thin horny sheaths on cutting margins, upper jaw cutting edge width smaller than half mouth width (17.8 % – 43.2 % of mouth width). Lips thick, well developed, with pearl-like papillae; central portion of anterior papillae arranged in one row with 2–4 well developed papillae, size slightly larger than other lateral side papillae; lateral portions of anterior papillae in several rows; medial pad on lower lip heart-shaped, or bisected into two oval-shape pads, rarely grooved on surface; lateral lobes on lower lip covered with multiple developed papillae, posteriorly disconnected from each other behind medial pad and laterally connected with upper lip anterior papillae at mouth corner (Fig. 3 A, B ).

Body covered with moderately small cycloid scales. Lateral line complete, almost straight in lateral center, slightly bent down under dorsal origin. Lateral line scales 36 (20 specimens), 37 (37), 38 (17), 39 (2); scales above lateral line 3.5 (76); scales below lateral line 1 (1), 1.5 (25), 2 (50); pre-dorsal scales 8 (7), 9 (33), 10 (35), 11 (1); circumpeduncular scales 12 (76). Midventral region of body scaleless only before pectoral-fin base end.

Dorsal fin with three unbranched and seven (76 specimens) branched rays; distal margin slightly concave, origin nearer to snout than caudal-fin base. Pectoral fin with one unbranched and 11 (12), 12 (50), 13 (14) branched rays; tip of adpressed not reaching anterior margin of pelvic-fin base. Pelvic fin with one unbranched and seven (76) branched rays, inserted below 2 nd or 3 rd branched dorsal-fin ray; tip of adpressed reaching midway to anal-fin origin. Anal fin with three unbranched and six (76) branched rays; origin nearer to caudal-fin base than to pelvic-fin insertion. Caudal fin deeply forked, with nine branched rays on upper lobes and eight branched rays on lower lobes, lobes pointed.

Total vertebrae 4 + 34 (holotype). Gill rakers rudimentary. Pharyngeal teeth “ 5–5 ” (in one row). Air-bladder small, anterior chamber enveloped in thick fibrous capsule; posterior chamber small, elongated oval shaped, length less than half eye diameter (length 30.4 % – 34.9 % of eye diameter), 9.2 % – 11.8 % of head length.

Coloration in life.

Dorsal side of head and body yellowish grey, mid-lateral side shallow yellowish grey, and ventral side grayish white. Dorsal side of body with four distinct black crossbars (1 st and 2 nd at dorsal-fin base origin and ending respectively, 3 rd at vertical position above anal-fin base origin, 4 th on caudal peduncle respectively). Lateral side with seven or eight small black blotches; margin of scales above lateral line slightly black pigmented, lateral-line scales without obvious black spots, margin of first row below lateral line slightly black pigmented. One fluorescent green strip extend above lateral line. Interorbital region without black crossbar. Operculum and suborbital region with two distinct black blotches (one between anterior margin of eye and upper lip, the other expanded from posterior orbit to opercular) and one small black blotch exist between 2 nd and 3 rd suborbital plate. One black blotch above pectoral-fin base. Fins translucent, with small black pigments on some fin rays; dorsal-fin rays with some black spots; pectoral fin, pelvic fin with tiny black spots and lines; anal fin without spots; caudal-fin rays with two rows of black spots.

Coloration in preservation.

Dorsal side of head and body brownish yellow, mid-lateral side shallow brownish yellow, and ventral side grayish white. Dorsal side of body with four distinct black crossbars in same position as live individual. Lateral side with seven or eight small dark grey blotches; margin of scales above lateral line slightly black pigmented, lateral-line scales without obvious black spots, margin of first row below lateral line slightly black pigmented. The fluorescent green strip faded. Interorbital region without black crossbar. Operculum and suborbital region with two distinct black blotches in same position as live individual, and one small black blotch exist between 2 nd and 3 rd suborbital plate. One black blotch above pectoral-fin base. Fins pale, with small black pigments on some fin rays; dorsal-fin rays with some black spots; pectoral fin, pelvic fin with tiny black spots and lines; anal fin without spots; caudal-fin rays with two rows of black spots. The black pigments on fin rays faded after long-time preserve.

Sexual dimorphism.

No significant sexual dimorphism observed.

Distribution.

Microphysogobio tungtingensis is distributed in the Xiangjiang River system and the Lake Dongting of the middle Yangtze River basin. It is also found distributed in the Xijiang River system, which belongs to the Pearl River basin (Fig. 4 ).

Habitat and biology.

Microphysogobio tungtingensis inhabits the slow flowing water of rivers. It usually appears in areas with sandy bottoms with gravel and pebbles like other congeners. It can also be found in the water body with muddy bottom.

Etymology.

The name, tungtingensis, refers to its type locality, Lake Dongting. Chinese common name for this species is “ 洞庭小鳔鮈 ”.

Figures

Figure 1. Microphysogobio tungtingensis, holotype, AMNH 8447, 51.4 mm SL A lateral view B dorsal view C ventral view; photographed by Dr. Thomas Vigliotta.

Figure 2. Lateral (A), dorsal (B), and ventral (C) views of Microphysogobio tungtingensis, ASIZB 240560, 81.8 mm SL, from the Jinjianghe River, a tributary of the Xiangjiang River, in Yuelu District, Changsha City, Hunan Province; Lateral (D), dorsal (E), and ventral (F) views of M. elongatus (= M. tungtingensis), ASIZB 240426, 72.3 mm SL, from the Lijiang River, the Pearl River Basin, in Pingle County, Guilin City, Guangxi Autonomous Region.

Figure 3. Lip papillae patterns of Microphysogobio species: A M. tungtingensis, ASIZB 240560 B M. elongatus (= M. tungtingensis), ASIZB 240426 C M. punctatus sp. nov., holotype, ASIZB 240329 D M. punctatus sp. nov., ASIZB 240300 E M. microstomus, SHOU 20231209017 F M. zhangi, holotype, ASIZB 204677 G M. vietnamica, ASIZB 240571 H M. bicolor, ASZIB 220638.

Figure 4. The distribution of the Microphysogobio punctatus sp. nov., M. tungtingensis and M. bicolor. “ T ” in circles indicates the type locality of each species.