Homatula robusta, Min & Zhao & Shi & Yang, 2022

Min, Rui, Zhao, Yahui, Shi, Jingsong & Yang, Junxing, 2022, A new species of Homatula (Teleostei, Cobitoidea, Nemacheilidae) from the Pearl River drainage, Yunnan, China, ZooKeys 1089, pp. 109-124 : 109

Homatula robusta sp. nov.

Figs 1 , 2 , 3 , 4 , 5

Material.

Holotype. KIZ 2009000125, 83.12 mm SL; collected by Wansheng Jiang and Weiying Wang on 14 March 2009 at Changdi village , Luoping County, Qujing City , Yunnan Province, China; Nanpanjiang River , upper Pearl River (25°02'N, 104°30'E; ca 1210 m) . Paratypes. KIZ 2009000122, 144, 146, 3 ex. 61.16-81.32 mm SL, same data as for holotype .

Diagnosis.

The new species can be distinguished from all other species of Homatula by having the following combination of characters: naked and robust body with well-developed crests (caudal peduncle depth as a percentage of its length: 70.5-78.5%), lateral line complete, median notch on lower jaw, median gap on lower lip, three pairs of short barbels, with maxillary barbels extending posteriorly to the anterior edge of eyes, branched dorsal-fin rays 8½, emarginated caudal fin, and vertebrae 37-39.

Description.

Anterior body cylindrical, posterior body laterally compressed; robust, depth 5.8-6.3 times in length. Caudal peduncle stout, depth 1.27-1.42 times in its length. Crests on dorsal and ventral midlines present and supported by rudimentary procurrent caudal-fin rays; dorsal crest starting immediately posterior of dorsal-fin base, ventral crest starting immediately posterior of anal-fin base.

Snout blunt in lateral view, cheeks inflated. Eyes elliptical horizontally, dorsolaterally positioned. Mouth inferior, slightly arched. Anterior nostril in flap, next to posterior nostril. Lips moderately thick, upper lip smooth, slightly notched medially, lower lip with shallow furrows and median gap. Processus dentiformis on upper jaw present with circular arc edge; lower jaw spoon-like with a median notch. Three pairs of barbels, maxillary barbel reaching anterior margin of eye, outer rostral barbel reaching inner corner of mouth and inner rostral barbel not.

Dorsal-fin rays iv, 8½, distal margin slightly convex. Pectoral-fin rays 11, reaching about halfway from insertion of pectoral fin to insertion of pelvic fin. Pelvic-fin rays 6-8, reaching close to anus, inserted opposite of the first branched dorsal-fin ray. Anus located 1.53-2.17 times eye diameter in front of anal-fin origin. Anal-fin rays iii, 5½. Caudal-fin rays 9+8, distal margin of caudal fin emarginated with upper and lower lobes almost equal in length. Moderate axillary pelvic lobe with free tip.

Body scaleless, or sparse scales scattered along lateral line after posterior end of anal-fiin base, embedded beneath skin. Lateral line completed with 85-89 pores. Supraorbital pores 7, postorbital pores 3, sub- and preorbital pores 12, preoperculo-mandibular pores 10, supratemporal pores 3.

Vertebrae (three specimens), 4+37-39; four hypural elements with h-1 & h-2 fused, epurale present, last four neural spines (ns-1 to ns-4) and last three haemal spines (hs-1 to hs-3) on the caudal vertebrae are significantly enlarged. U-shaped stomach; intestine almost straight, with small bend next to stomach posterior. Longest recorded length is 83.1 mm SL, 95.7 mm total length (KIZ 2009000125, holotype).

Coloration of preserved specimens.

Body light brown with vertical brown bars in formalin-fixed specimens. Bars on predorsal body usually blurred and indistinct, or countable and separated by extraordinary narrow interspaces just in KIZ 2009000122. Bars and interspaces getting wider towards caudal-fin base and approximately equal width on posterior body. Usually, bars regularly shaped and jointed on dorsal midline from opposite sides, or two bars met on upper body and last bar diffused or formed by two combined bars (KIZ 2009000122). Dark black bar on caudal-fin base, reaching dorsal and ventral extremities. All fin rays pale brown and covered by melanophores, series of stripes halfway up each dorsal-fin ray. Color in alcohol-fixed specimens is paler than those in formalin-fixed specimens.

Sexual dimorphism.

No sexual dimorphism was observed.

Etymology.

Robusta is a Latin word meaning ‘strong’, in reference to the stout body and caudal peduncle. The Chinese common name is suggested as 粗壮荷马条鳅.

Distribution.

Only known from the type locality, Changdi village, Luoping County, Qujing City, Yunnan Province, China (Fig. 5 ).

Figures

Figure 1. Lateral A dorsal B and ventral views C of H. robusta sp. nov., holotype, KIZ 2009000125, 83.12 mm SL.

Figure 2. Homatula robusta sp. nov., paratype, KIZ 2009000122, 81.32 mm SL, head in lateral A dorsal B and ventral C views.

Figure 3. Lateral view of H. robusta sp. nov. KIZ 2009000122 paratype A H. longidorsalis KIZ 1987003989 B H. nanpanjiangensis KIZ 1994000023 C H. potanini KIZ 2010000266 D.

Figure 4. Lateral CT scans of: A H. robusta sp. nov., KIZ 2009000125, lateral view and structure of caudal skeletons B H. nanpanjiangensis, KIZ 1994000029, lateral view and structure of caudal skeletons C H. wenshanensis, KIZ 2014005686, lateral view. Abbreviations: ph-partypurale, ns-neural spine, hs-haemal spine, h-hypural, epu-epurale, pst-pleurostyle.

Figure 5. Distribution of Homatula from the Nanpanjiang River.