Liobagrus chenhaojuni Chen, Guo & Wu, 2024

Chen, Zhong-Guang, Guo, Yan-Shu, Dai, Yu-Ting, Huang, Xiao-Chen, Huang, Jun-Hao, Jiang, Jiao, Ouyang, Shan, Wen, An-Xiang & Wu, Xiao-Ping, 2024, A new species of Liobagrus Hilgendorf, 1878 (Teleostei, Siluriformes, Amblycipitidae) from the lower Changjiang River basin in southeast China, Zoosystematics and Evolution 100 (2), pp. 555-563 : 555-563

publication ID	https://doi.org/ 10.3897/zse.100.122472
publication LSID	lsid:zoobank.org:pub:88AE11F0-FC3E-44E2-920B-273CA4370F0F
DOI	https://doi.org/10.5281/zenodo.11206563
persistent identifier	https://treatment.plazi.org/id/9966A844-20BC-4DCD-9E09-A5FFA9F14659
taxon LSID	lsid:zoobank.org:act:9966A844-20BC-4DCD-9E09-A5FFA9F14659
treatment provided by	Zoosystematics and Evolution by Pensoft
scientific name	Liobagrus chenhaojuni Chen, Guo & Wu
status	sp. nov.

Treatment

Liobagrus chenhaojuni Chen, Guo & Wu sp. nov.

Figs 1 View Figure 1 , 2 A – C View Figure 2 , Table 2 View Table 2

Liobagrus styani Li & Shimatani, 2016: 165–167 (Tiaoxi River, Zhejiang, China). View in CoL

Type material.

Holotype. 24 _ NCU _ XPWU _ Y 01 , Siling Reservoir [四岭水库], Tiaoxi River [苕溪], Yuhang district [余杭区], Hangzhou City [杭州市], Zhejiang Province [浙江省], China, 30 ° 25 ' 42 " N, 119 ° 45 ' 18 " E, leg. Hao-Jun Chen, February 2024 GoogleMaps .

September 2022. Paratypes. 24 _ NCU _ XPWU _ Y 02 – 16, n = 15, other information same as holotype GoogleMaps ; 22 _ NCU _ XPWU _ Y 01 – 17, n = 17, leg. Zhong-Guang Chen & Hao-Jun Chen, September 2022, other information same as holotype GoogleMaps ; 22 _ NCU _ XPWU _ Y 18 – 25, n = 8, IHB-T-A 0000007 – 8, n = 2, Tiaoxi River [苕溪], Deqing County [德清县], Huzhou City [湖州市], Zhejiang Province [浙江省], China, leg. local people, September 2022 .

Diagnosis.

Liobagrus chenhaojuni sp. nov. is a member of the group defined by the presence of a smooth posterior edge of the pectoral-fin spine (i. e., L. reinii , L. formosanus , L. styani , L. nantoensis , L. anguillicauda , L. marginatoides , and L. aequilabris ). It can be distinguished from all other species in this group by the following characteristics: the upper jaw is longer than the lower jaw (vs. equal in L. aequilabris and L. formosanus ; shorter in L. marginatoides ); the maxillary barbels reach the middle of the pectoral fin (vs. reach the pectoral-fin insertion in L. styani , L. reinii , and L. nantoensis ); presence of irregular blotches on the lateral body (vs. absence in L. formosanus , L. nantoensis , L. anguillicauda , L. marginatoides , and L. aequilabris ); the caudal fin is rounded (vs. sub-truncate in L. marginatoides ); the caudal fin length ranges from 16.5 % to 19.9 % standard length (vs. 13.1–16.2 in L. styani , 20.3–27.0 in L. anguillicauda and 20.1–26.9 in L. aequilabris ); it possesses 39–41 post-Weberian vertebrae (vs. 35–37 in L. aequilabris ), the anal-fin rays range from 15 to 17 (vs. 12 in L. nantoensis ) (Table 3 View Table 3 ).

Description.

Morphometric data for type specimens are shown in Table 2 View Table 2 . Body elongated, anteriorly depressed (wider than deep), and posteriorly evenly compressed to the tail. Lateral line short, with 6–9 pores. Head depressed and broad when viewed dorsally, with a broadly rounded snout in dorsal view. Anterior nostril tubular, with a rim bearing a fleshy flap forming a short tube; posterior nostril pore-like, with the rim posteriorly confluent with the base of the nasal barbel. Eyes small, dorsolateral, and subcutaneous. Mouth terminal, with the upper jaw noticeably longer than the lower jaw, lips thickened. Premaxillary and mandibular tooth pads curved, bearing small and setiform teeth; palatine teeth absent. Four pairs of barbels: the maxillary barbel long, extending to the pectoral-fin insertion; nasal barbel short, not reaching the gill-membrane margin; inner mandibular barbel approximately half the length of the outer mandibular barbel and does not extend to the pectoral-fin insertion; outer mental barbel longest, reaching the middle of the pectoral fin.

Dorsal fin II, 5–6 rays, with a convex distal margin; tip of adpressed fins does not reach the pelvic-fin insertion. Dorsal-fin spine covered by thick, straight skin with smooth anterior and posterior margins, slightly shorter than the pectoral-fin spine. Adipose fin high, with its base longer than the anal-fin base, confluent with the caudal fin without a marked incision at the confluence. Pectoral fin I, 7–8 rays, with its origin at the vertical through the edge of the operculum, partially covered by the opercular membrane. Pectoral-fin spine long and sharp, with smooth anterior and posterior margins (Fig. 1 D View Figure 1 ), reaching the dorsal-fin insertion. Pelvic fin i, 5–6 rays, short, with the adpressed tip not reaching the anal-fin origin. Anal fin 15–17 rays with a rounded distal margin, and its tip approaches the origin of the ventral procurrent caudal-fin rays, longer than the dorsal-fin base but shorter than the adipose-fin base, with a convex distal edge. Anus closer to the pelvic-fin insertion than to the anal-fin origin. Caudal fin rounded, with 43–50 rays. Vertebral column consists of 39–41 post-Weberian elements.

Body generally dark brown to brownish red, adorned with irregular yellowish blotches that fade to light yellow ventrally. All barbels grayish white to light yellow, while dorsal fins dark brown, and adipose and caudal fins grayish white to light brown. All fins exhibit narrow, grayish white to light yellowish distal margins (Fig. 2 A, B View Figure 2 ). An albino individual was found, exhibiting a generally pink body without irregular yellowish blotches (Fig. 2 C View Figure 2 ).

Etymology.

This species is named after Mr. Hao-Jun Chen, who assisted in the field survey.

Vernacular name.

浙江䱀 (Pinyin: zhe jiang yang).

Distribution and ecology.

Liobagrus chenhaojuni sp. nov. is exclusively found within the Tiaoxi River basin (Fig. 3 View Figure 3 ). Within this habitat, it typically resides at the bottom of the stream with medium pebbly substrates, together with Rhinogobius leavelli (Herre, 1935) , Microphysogobio bicolo r (Nichols, 1930), Vanmanenia stenosoma (Boulenger, 1901) , Acrossocheilus fasciatus (Steindachner, 1892) , Opsariichthys bidens Günther, 1873 , and Zacco tiaoxiensis Zhang, Zhou & Yang, 2022 (Fig. 4 View Figure 4 ).

Molecular analyses.

A dataset consisting of 33 Cytb sequences and five outgroup taxa was employed for phylogenetic analyses (Table 1 View Table 1 ). The alignment of Cytb exhibited a length of 1116 characters, with 343 variable sites and 313 sufficiently informative sites. Phylogenetic analyses generated ML and BI trees with largely congruent topologies (Fig. 5 View Figure 5 ). Notably, species from China with a smooth posterior edge of the pectoral-fin spine formed a monophyletic group, while those with a serrated posterior edge of the pectoral-fin spine constituted a paraphyletic group. The validity of Liobagrus chenhaojuni sp. nov. is supported by the molecular-phylogenetic result. It belongs to the group with a smooth posterior edge of the pectoral-fin spine, and the phylogenetic relationship within the group is represented as Liobagrus chenhaojuni sp. nov. + ( L. anguillicauda + ( L. aequilabris + L. styani )). The genetic distances between Liobagrus chenhaojuni sp. nov. and other congeneric species ranged from 5.8 % to 14.2 % (Suppl. material 1).