Niwaella brevipinna Chen & Chen, 2017

Chen, Yongxia, He, Dekui, Chen, Hao & Chen, Yifeng, 2017, Taxonomic study of the genus Niwaella (Cypriniformes: Cobitidae) from East China, with description of four new species, Zoological Systematics 42 (4), pp. 490-507 : 498-500

Niwaella brevipinna Chen & Chen , sp. nov. ( Figs 18–22 )

Cobitis laterimaculata Nakajima et al. 2013 (nec. Yang & Zheng, 1984): 331 (from the East Tiaoxi River, Fig. 7h ).

Holotype. HU 1608312, 55.5 mm SL, the Dongshaoxi River (a tributary of the Shaoxi River), Lin'an (30°24′N, 119°68′E), Zhejiang, China, April 2016, collected from the Lin'an farm product market by Yongxia Chen.

Paratypes. HU 1608208, 1608213, 1608215, 1608305–7, 1608299–301, 1608303, 10 ex., 38.9–58.0 mm SL, same data as holotype .

Diagnosis. The new species is distinguishable from its congeners by the following characteristics: color pattern consisting of narrow brown vertical bars discontinuous along dorsal upper blotches; a row of 15–18 vertical stripes below the lateral midline ( Figs 18 , 22 ); lower lip wrapped the mandible, with moderately developed mental lobes ( Fig. 19 ); suborbital spine thick and curved, with short processus latero-caudalis, less than one-fifth of processus medio-caudalis ( Fig. 20 ); subdorsal scales small and oval, with a large focal area, 24–29 radial grooves, and 9–12 supplementary ones ( Fig. 21 ). It is similar to N. laterimaculata in color pattern, but differs from it in the lower lip wrapped the mandible, with developed mental lobes (vs. lower lip and mandible separated, with undeveloped mental lobes); 4 branched rays in anal fin (vs. 5); 6 branched rays in dorsal fin ( Fig. 22 ) (vs. 7 ( Fig. 26 )); 5 branched rays in ventral fin ( Fig. 22 ) (vs. 6); suborbital spine thick, with long processus latero-caudalis, less than one-fifth of processus medio-caudalis (vs. suborbital spine slender, with short processus latero-caudalis, less than one-seventh of processus medio-caudalis); caudal peduncle long, length of caudal peduncle 6.7–8.0 (mean 7.5) in SL (vs. caudal peduncle short, length of caudal peduncle 7.3–10.7 (mean 8.9) in SL).

Description ( Figs 18–22 , Table 2). D. III–6; A. III–4; V. I–5; P. I–6; C. IV–14–15–IV. Body elongate, compressed. Head small. Snout bluntly rounded. Preorbital part of head shorter than postorbital part of head. Mouth small, inferior, with three pairs of short barbels. Length of maxillo-mandibular barbels equal to diameter of eye. Lips fleshy with numerous transversal wrinkles on the surface. Lower lip wrapped the mandible, with moderately developed mental lobes ( Fig. 19 ). Suborbital spine thick and curved, with short processus latero-caudalis, less than one-fifth of processus medio-caudalis ( Fig. 20 ). Subdorsal scales small and oval, with a large focal area, 24–29 radial grooves, and 9–12 supplementary ones ( Fig. 21 ).

Dorsal fin short, inserted the midway between the posterior margin of eye and the base of the caudal fin, length shorter than that of head. Length of the dorsal fin 6.8–7.0 (mean 7.4) in SL. Pectoral fins short, length of the pectoral fin 9.5–11.7 (mean 10.6) in SL. Ventral fins approximately at the same level as the second branched dorsal-fin ray. Anal fin located in far behind dorsal extremity and not reach the caudal fin. Anal orifice close to the anal fin. Caudal fin emarginated tip. Adipose crests developed. Lateral line short, not exceeding length of the pectorals.

Pigmentation pattern. Head sprinkled with many black spots, a black stripe extended from the insertion of the rostral barbels through the eye to the occiput. On the dorsum, an inconspicuous black stripe with a surface pigment containing 17– 24 rectangular blotches, among which 8–13 oval or rectangular blotches present from the occiput to the base of the dorsal fin, 2 on the dorsal fin, and 7–9 behind the dorsal fin, gaps between the rectangular blotches narrower than their widths. A row of 15–18 vertical stripes below the lateral midline, with the stripe being for narrower than their interspaces; many small vertical bars with irregular speckles present on the dorsolateral surface. One conspicuous, small, oblique rectangular spot present on the upper half of the caudal fin base, the upper spot smaller than the diameter of the eye. Three or four rows of brownish dots present on the dorsal and caudal fins.

Sexual dimorphism. Not obvious in external morphology.

Distribution. This new species occurs in the Dongshaoxi River (a tributary of the Shaoxi River) in Zhejiang Province in east China ( Fig. 1 ).

Remarks. Two new species, N. fimbriata Chen & Chen , sp. nov. and N. brevipinna Chen & Chen , sp. nov. are both living in the Dongshaoxi River. Two collection trips were organized during March to April in 2015 and 2016 to obtain more samples. However, these two species were collected in different year, respectively. It is not clear whether they are sympatric species. Maybe they are spatially separated in the areas of the Dongshaoxi River. Additionally, Nakajima et al. (2013) wrongly recorded this species as Cobitis laterimaculata in the Dongshaoxi River.

Etymology. The species name is derived from the Latin brevis, meaning short, and pinna, meaning feather, in reference to with short dorsal fin.

Figures

Figure 1. Currently known localities of the eight Niwaella species in China.

Figures 18–21. Niwaella brevipinna Chen & Chen, sp. nov., the Dongshaoxi River, Lin'an, Zhejiang, China. 18. Holotype, HU 1608312, lateral view. 19. Mouth characters, front view. 20. Suborbital spine, left dorsal view, right interior view. 21. Subdorsal scales, dorsal view. Scale bars: 18=1cm; 19–20=1mm; 21=100μm.

Figures 22–23. Niwaella brevipinna Chen & Chen, sp. nov., color in life. 22. Lateral view. 23. Dorsal view. Scale bars=1cm.

Figures 6–7. Niwaella nigrolinea Chen & Chen, sp. nov., color in life. 6. Lateral view. 7. Dorsal view. Scale bars=1cm.

Figures 26–27. Niwaella laterimaculata, color in life, the Yongjiang River, Xikou, Zhejiang, China. 26. Lateral view. 27. Dorsal view. Scale bars=1cm.