Oreonectes guilinensis, Huang & Yang & Wu & Zhao, 2020

Huang, Jin-Qing, Yang, Jian, Wu, Zhi-Qiang & Zhao, Ya-Hui, 2020, Oreonectes guilinensis (Teleostei, Cypriniformes, Nemacheilidae), a new loach species from Guangxi, China, Journal of Fish Biology 96 (1), pp. 111-119 : 112-116

3.1 | Oreonectes guilinensis sp. nov. (Figures 1, 2 and Table 2 )

3.1.1 | Holotype

ASIZB208002 , 66.3 mm standard length (L S), from Xingping , Yangshuo County, Guilin City , Guangxi Zhuang Autonomous Region , China, a tributary of Lijiang river , Pearl River system (24 53 0 30.77 00 N, 110 33 0 45.62 00 E), collected in May 2016 by Jian Yang .

3.1.2 | Paratypes

ASIZB208001 , ASIZB208003-208007 , KIZ2016007378 , 51.9 – 73.0 mm L S; data as for holotype.

3.1.3 | Diagnosis

The new species is distinguished from other species of the genus Oreonectes . by the combination of following characteristics: caudal fin rounded; pelvic fin short, with a short distance to anus, body (except head) completely covered by scales; lateral line incomplete, with 4 – 6 pores; body width (W B) 14.8% – 16.4% L S (v. 8.8% – 12.3% in congeners); body yellowish-brown, with a dark brown lateral stripe on the flank. Two chambers of air-bladder, posterior chamber developed, filling body cavity, connected with anterior chamber by a long, slender tube.

3.1.4 | Description

Body elongate and cylindrical, with depth decreasing from dorsal-fin origin to caudal-fin base. Head slightly depressed and flattened, width greater than depth. Snout round, snout length shorter than postocular head length. Mouth inferior, curved. Upper and lower lips smooth. Three pairs of barbels: inner rostral extending anterior margin of eye, outer rostral and maxillary barbels extending over posterior margin of eye. Nostrils separate with a short distance. Anterior nostril in a short tube, which extend into a short barbel. Eyes normal.

Dorsal-fin rays ii-6, pectoral-fin rays i-9-10, pelvic-fin rays i – 6, anal-fin rays iii – 5, caudal fin branched 13 – 14. Dorsal fin short, origin closer to caudal-fin base than to snout tip, posterior to pelvic-fin origin, distal margin round. Pectoral fin almost reaching half distance to pelvic fin. Pelvic fin with a short distance (2.5 to 4 mm) to anus. Anal fin origin next to anus with a short distance. Caudal fin rounded. Caudal peduncle without adipose crests along both dorsal and ventral sides. Vertebra 4 + 33 – 36.

Except head, body completely covered by scales; lateral line incomplete, with 4 – 6 pores; cephalic lateral-line system, with 6 – 9 supraorbital, 4 + 5 – 9 infraorbital pores, 3 – 4 canal pores, with 3 – 7 preoperculo-mandibular canal pores. Two chambers of air-bladder, posterior chamber developed, filling body cavity, connected with anterior chamber by long, slender tube (Figure 3).

3.1.5 | Coloration

Body yellowish-brown with a dark brown lateral stripe on flank, many irregularly shaped speckles, anal-fin hyaline, other fins with irregularly black dots (Figure 2). Colour in alcohol similar to life colour, except body a uniform dull yellow, turn into pale brown over time (Figure 1).

3.1.6 | Distribution

This new species is only found Shigumen village Xingping town Yangshuo County, Guilin City, Guangxi Zhuang Autonomous Region of southern China (24 53 0 30.77 00 N, 110 33 0 45.62 00 E; Figure 4).

3.1.7 | Etymology

The species name derives from the Chinese name Guilin, the name of the city where the specimens were collected.

3.1.8 | Genetic comparisons

The molecular phylogenies from the ML analyses (Figure 5) show that Oreonectes guilinensis sp. nov. and the type species O. platycephalus form a monophyletic group with strong support (100 bootstrap), sister to the Lefua clade. Interestingly, these controversial species including Oreonectes shuilongensis Deng, Xiao, Hou & Zhou 2016 , Oreonectes daqikongensis Deng, Wen, Xiao & Zhou 2016 and Oreonectes jiarongensis (Lin, Li & Song 2012) were resolved in a well-supported clade with Troglonectes furcocaudalis (Zhu & Cao 1987) (100 bootstrap). On this basis, as well as morphological comparisons, we are confident in assigning the new species to the genus Oreonectes .

Tables

TABLE 2 Meristics and morphometrics of six species from the genus Oreonectes

Character	O. guilinensis sp. nov.		O. platycephalus		O. anopthalmus		O. guananensis		O. polystigmus		O. luochengensis
	Range	Mean ± SD	Range	Mean ± SD	Range	Mean ± SD	Range	Mean ± SD	Range	Mean ± SD	Range	Mean ± SD
No. of specimen	8		10		3		6		11		5
Dorsal fin	7		7		7		7		7		7
Anal fin	5		7		5		5		5		5
Pectoral fin	9 – 10		9 – 10		10		11 – 12		10 – 11		11 – 12
Pelvic fin	6 – 7		7		4		7 – 8		6 – 7		7
Caudal fin	13 – 14		14 – 16		12		15 – 16		14 – 15		15 – 17
Lateral line pores	4 – 6		13 – 17		–		7 – 10		5 – 14		11 – 13
Standard length (L S, mm)	51.9 – 73.0	65.0 ± 6.1	46.2 – 72.5	52.3 ± 7.5	26.5 – 40.1	34.8 ± 7.3	53.0 – 76.6	63.9 ± 9.9	34.3 – 58.6	45.4 ± 8.3	66.8 – 73.9	71.6 ± 2.9
% L S
Body height	16.5 – 18.7	17.5 ± 0.8	11.5 – 15.8	13.6 ± 1.5	11.6 – 13.6	12.6 ± 1.0	15.1 – 18.3	16.5 ± 1.1	11.0 – 16.7	14.3 ± 1.7	14.6 – 17.2	16.3 ± 1.0
Maximum body height	17. – 20.0	18.7 ± 0.8	12.3 – 17.1	14.8 ± 1.7	12.8 – 14.2	13.4 ± 0.7	15.8 – 19.3	17.5 ± 1.2	13.9 – 19.4	16.3 ± 1.9	16.4 – 17.8	17.2 ± 0.5
Body width	14.0 – 16.7	15.5 ± 0.9	8.3 – 9.4	8.8 ± 0.3	9.6 – 11.8	10.5 ± 1.2	11.3 – 13.1	12.3 ± 0.6	6.5 – 12.6	8.5 ± 1.9	12.1 – 12.5	12.3 ± 0.2
Maximum body width	17.2 – 19.8	18.4 ± 0.9	10.6 – 15.4	13.0 ± 1.4	13.2 – 15.9	14.3 ± 1.4	13.9 – 16.8	15.0 ± 1.0	11.5 – 17.1	13.8 ± 1.7	14.8 – 16.0	15.4 ± 0.5
Body width at anus	11.5 – 13.5	12.4 ± 0.6	7.2 – 9.1	8.3 ± 0.6	7.9 – 10.3	9.2 ± 1.2	9.0 – 10.4	9.7 ± 0.5	5.3 – 10.1	7.0 ± 1.6	9.6 – 10.0	9.8 ± 0.2
Predorsal length	57.0 – 61.6	59.6 ± 0.6	57.3 – 61.0	59.4 ± 1.2	60.5 – 64.5	62.4 ± 2.0	56.7 – 58.0	57.3 ± 0.5	55.8 – 63.3	60.2 ± 2.3	56.0 – 58.0	58.3 ± 0.8
Dorsal-fin length	15.9 – 19.1	17.5 ± 1.0	17.6 – 19.9	19.1 ± 0.7	13.7 – 17.0	15.4 ± 1.6	15.7 – 18.7	17.1 ± 0.9	16.3 – 20.6	18.1 ± 1.2	17.7 – 19.1	18.6 ± 0.5
Dorsal-fin base length	6.6 – 10.2	9.0 ± 1.1	8.7 – 11.5	10.0 ± 0.7	9.4 – 10.8	9.9 ± 0.7	9.1 – 9.6	9.4 ± 0.2	8.6 – 12.1	10.2 ± 1.2	10.1 – 10.5	10.3 ± 0.2
Prepelvic length	54.7 – 59.0	56.5 ± 1.7	48.1 – 51.3	49.8 ± 1.0	58.5 – 61.3	59.6 ± 1.5	53.2 – 55.4	54.0 ± 0.8	50.4 – 55.6	53.6 ± 1.7	51.9 – 57.9	54.0 ± 2.4
Pelvic-fin length	12.0 – 13.9	13.2 ± 0.6	16.9 – 19.1	18.1 ± 0.7	9.9 – 10.8	10.3 ± 0.5	12.2 – 13.7	13.1 ± 0.5	12.9 – 15.9	13.9 ± 1.0	12.2 – 13.2	12.5 ± 0.4
Pelvic-fin base length	3.1 – 3.4	3.3 ± 0.1	3.5 – 5.7	4.2 ± 0.7	1.9 – 2.9	2.5 ± 0.5	3.3 – 3.7	3.5 ± 0.2	2.3 – 3.6	2.9 ± 0.5	3.0 – 3.7	3.3 ± 0.2
Pre-anus length	71.4 – 75.9	73.3 ± 1.5	63.8 – 70.5	67.8 ± 2.0	68.6 – 72.2	69.9 ± 2.0	68.9 – 71.8	70.6 ± 1.0	67.3 – 73.2	71.1 ± 1.6	68.4 – 73.5	70.9 ± 1.8
Pre-anal length	77.2 – 82.9	80.5 ± 1.9	72.7 – 79.0	75.7 ± 2.1	74.3 – 77.4	75.4 ± 1.7	755.9 – 78.1	77.0 ± 0.9	73.0 – 78.5	77.1 ± 1.7	75.0 – 79.4	77.8 ± 1.7
Anal fin length	14.0 – 16.0	15.0 ± 0.7	16.8 – 20.6	18.4 ± 1.3	11.7 – 15.3	13.4 ± 1.8	13.7 – 15.4	14.3 ± 0.8	14.3 – 19.9	15.8 ± 1.5	15.1 – 16.4	15.8 ± 0.5
Anal-fin base length	6.0 – 7.2	6.7 ± 0.4	7.8 – 10.7	8.9 ± 0.9	5.9 – 9.4	7.9 ± 1.8	6.8 – 8.4	7.4 ± 0.6	2.5 – 9.7	8.0 ± 2.0	7.3 – 7.7	7.4 ± 0.2
Prepectoral length	20.8 – 24.8	23.5 ± 1.3	19.6 – 23.4	21.6 ± 1.0	24.0 – 26.1	25.4 ± 1.2	20.3 – 22.6	21.0 ± 0.9	19.9 – 25.5	23.1 ± 1.8	19.2 – 20.9	19.8 ± 0.6
Pectoral-fin length	15.6 – 17.5	16.6 ± 0.7	16.8 – 20.4	18.7 ± 1.1	13.1 – 15.2	13.9 ± 1.1	15.5 – 16.6	16.1 ± 0.4	13.4 – 18.6	15.3 ± 1.7	15.8 – 17.2	16.6 ± 0.6
Pectoral-fin base length	3.1 – 4.5	3.7 ± 0.5	3.5 – 5.4	4.7 ± 0.6	3.6 – 5.0	4.3 ± 0.7	3.5 – 4.8	4.0 ± 0.5	2.8 – 5.1	3.5 ± 0.6	3.9 – 4.5	4.4 ± 0.3
Caudal-fin length	19.8 – 23.1	21.5	20.5 – 24.7	20.7 ± 1.5	13.6 – 19.1	15.9 ± 2.9	18.4 – 20.3	19.1 ± 0.8	13.5 – 23.1	19.1 ± 2.5	16.8 – 18.2	17.5 ± 0.5
Caudal-peduncle length	11.9 – 18.7	15.8	14.9 – 18.9	16.1 ± 1.1	17.3 – 18.2	17.7 ± 0.5	15.0 – 16.3	15.4 ± 0.5	14.2 – 16.5	15.2 ± 0.8	14.0 – 16.3	15.8 ± 0.8
Caudal-peduncle depth	10.5 – 11.7	11.1	8.0 – 12.1	10.8 ± 1.1	8.9 – 10.2	9.7 ± 0.6	9.4 – 10.9	10.3 ± 0.5	7.3 – 11.5	8.5 ± 1.4	9.2 – 10.3	9.8 ± 0.5
Head length (L H)	19.9 – 23.3	21.4	20.4 – 21.7	21.0 ± 0.4	24.3 – 25.4	24.9 ± 0.5	19.8 – 20.7	20.0 ± 0.3	16.6 – 24.9	22.4 ± 2.2	19.6 – 20.5	20.0 ± 0.4

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