Niwaella longibarba, Chen & Chen, 2005

Chen, Yifeng & Chen, Yongxia, 2005, Revision of the genus Niwaella in China (Pisces, Cobitidae), with description of two new species, Journal of Natural History 39 (19), pp. 1641-1651 : 1647-1649

Niwaella longibarba sp. n.

( Figures 1D , 2B , 3B , 4B , 5 )

Niwaella laterimaculata: Son and He (not Yan and Zheng) 2001, p 1–5 (Huangzhezhen, Shengxian County, Zhejiang Province).

Material examined

Holotype: no. 9607011, female, 57.7 mm TL, 48.7 mm SL. Type locality: The Cao’ejiang River, Huangzezhen , 29 ° 36.39N, 120 ° 54.49E, Chengxian County, Zhejiang Province, 10 July 1996.

Paratypes: nos 9607012–55, male and female, 51.2–75.6 mm TL, 43.1–65.5 mm SL, 34 specimens from type locality.

Other material examined. Nos 471035, 471045–46, male and female, 53.4– 46.1 mm TL, 46.7– 39.1 mm ST, three specimens from the Cao’ejiang River , Chengxian County, 33 ° 44.99N, 105 ° 46.09E, Zhejiang Province , 1947.

All specimens kept in FFM, IHB, CAS, Wuhan, Hubei Province.

Etymology

The specific name longibarba is Latin for ‘‘with long barbel’’, and refers to the long maxillomandibular barbels.

Description D. iii-6; A. iii-5; V. i-6; P. i-7. Vertebral 4 + 41–42. Morphometric characters are given in

Table I.

Body elongated and laterally compressed. Dorsal surface and abdomen almost parallel. Head small, slightly compressed, snout bluntly rounded, length longer than that of space between eye and nape. Mouth small, inferior, with undeveloped mental lobes. Barbels slender, shorter than or slightly equal to eye diameter ( Figure 2B ). Eye interorbital width equal to or longer than diameter.

Dorsal fin moderately long, situated on front half of the space between nape and caudal fin, length shorter than that of head. Dorsal fin short and with tip rounded, the second branched ray the longest, not reaching one-quarter of the distance between pectoral fin and pelvic fin. Pelvic fin short and small, and approximately on the same line with the dorsal fin, reaching one-third of the distance between pelvic fin and anal fin. Anal fin short and small, situated on posterior half of the space between pelvic fin and caudal fin, tip blunt. Caudal fin long, tip emarginate. Anus close to anal fin. Caudal peduncle long, adipose crests developed. Lateral line short, exceeding length of pectorals.

No scales on the head and sides of head. Body scales are small, round, with a large, almost central focal area, 24–25 radial grooves and few supplementary radial grooves. The radial grooves in the front and on the side of scale are broad and sparse, at the base of scale closely spaced. The circular striae relatively scarce ( Figure 3B ). Suborbital spine curved opposite the caudal processes, and the mediorostral process is more developed in this species than others ( Figure 4B ).

Pigmentation pattern

Body pale yellowish. Head sprinkled with many black spots, a black stripe was visible from nape through eye to first barbel insertion. Dorsal body colour pattern 14–16 angular black stripes, moderately large, long diffuse dark vertical bar on the dorsolateral surface and 16– 19 blotches below the lateral midline. There are two or three striations on the caudal fin and dorsal fin, and a conspicuous dark spot on upper part of the caudal base.

Sexual dimorphism

Not evident.

Remarks

This new species is similar to N. laterimaculata in appearance, but differs from the latter in its colour pattern of a row of moderately large and long scattered dark brown vertical bars on the dorsolateral surface, versus small and densely scattered dark speckles on the dorsolateral surface, and by its two or three striations on the caudal fin, versus four or five. It is also distinguished from N. laterimaculata by its long barbels and undeveloped mental lobes, versus shorter barbels and developed mental lobes (Table II).

Distribution

Previously the species was known only in the Cao’ejiang River. Son and He (2001) misspelled the Cao’ejiang as the Caozejiang, and Chengxian County as Shengxian County.

Figures

Figure 1. Loaches of the genus Niwaella. (A) N. delicata; (B) N. multifasciata; (C) N. laterimaculata; (D) N. longibarba sp. n.; (E) N. xinjiangensis sp. n.

Figure 2. Ventral view of the mouth with barbels and mental lobes. (A) N. laterimaculata; (B) N. longibarba sp. n.; (C) N. xinjiangensis sp. n.

Figure 3. Subdorsal scales. (A) N. laterimaculata; (B) N. longibarba sp. n.; (C) N. xinjiangensis sp. n.

Figure 4. Suborbital spine. (A) N. laterimaculata; (B) N. longibarba sp. n.; (C) N. xinjiangensis sp. n.

Figure 5. Niwaella longibarba sp. n., holotype, female, no.9607011.