Rhinogobius lingtongyanensis, Chen & Wang & Chen & Shao, 2022

Chen, I-Shiung, Wang, Shen-Chih, Chen, Kwang-Yiao & Shao, Kwang-Tsao, 2022, A new freshwater goby of Rhinogobius lingtongyanensis (Teleostei, Gobiidae) from the Dongshi river basin, Fujian Province, southeastern China, Zootaxa 5189 (1), pp. 18-28 : 19-25

Rhinogobius lingtongyanensis new species

( Figures 1–3 )

Materals examined

Holotype: NTOUP 2015-04-303 , 30.8 mm SL, Field station no. 2015-03-6 B, Shar village , Darshi township near Lingtongyan mountain , Dongshi basin, Shaoan County, Janchou City, Fujian province, China, Coll. I-S. Chen, 10 Mar. 2015.

Paratypes: NTOUP 2015-04-304, 4 specimens, 30.2-38.5 mm SL, other data same as holotype.

Diagnosis

Rhinogobius lingtongyanensis can be well distinguished from all other congeners by the unique combination of the following features: (1) fins: second dorsal fin rays I/8; anal fin rays I/7; pectoral fin rays modally 16; (2) squamation: longitudinal scale series 25-27 (modally 26); perdorsal scales 3-6 (modally 5-6); (3) vertebral count 26; and (4) specific colouration: In male, lateral body with 6-7 major patches of irregularly grayish to brownish black marks; cheek blackish brown with four oblique grayish black stripes; branchiostegal membrane grayish blue without any light spots; first dorsal fin broad grayish brown band in middle, outer margin pinkish orange; pectoral fin base with longitudinal deep brown bar in upper region; and caudal fin gray with four vertical rows of brown spots, its base with a short brownish black bar.

Description

Body proportions in Table 1 . Body cylindrical anteriorly, compressed posteriorly. Head rather large, somewhat depressed in male. Eye large, dorsolateral. Snout pointed. Cheek somewhat fleshy in male. Lips thicks. Mouth oblique, rear edge not extending beyond vertical of anterior margin of eye. Both jaws with 3-4 rows of conical teeth, outer jaws enlarged. Tongue margin rounded. Anterior nostril in short tube and posterior nostril round. Gill opening restricted, extending ventrally near the vertical midline of opercle. Vertebral count 11 + 15 = 26 (in all 5 specimens).

Fins. D1 VI, D2 I/8; A I/7; P 16-17 (modally 17); V I/5+I/5 (distribution frequency in Table 1 ). D1 high and 3 rd and 4 th rays longest, with rear tip extending to vertical line of second branched ray of D 2 in male, but not reaching origin of D 2 in female. The rear tip of D2 and A rays while depressed fall well short of procurrent rays of C. P moderate large and oblong, its rear tip extending just to vertical line of anus in male, but not reaching this line in female. V rounded, spinous rays with somewhat pointed membrane lobe. C elliptical, rear edge rounded.

Scales. Body with large ctenoid scales, anterior predorsal area naked; posterior predorsal area and belly cycloid. LR 25-27 (modally 26); TR 8-9 (modally 8); PreD 3-6 (usually 5-6); and SDP 7-8 (modally 7). Head and prepelvic region naked. Anterior edge of midperdorsal squamation extending about to vertical of upper end gill-opening.

Head lateral-line system

Canals: Nasal extension of anterior oculoscapular canal with terminal poreσlocated in between anterior and posterior nostrils. The gap between two oculoscapular canals is very narrow and less than a half length of posterior oculoscapular canal. Anterior interorbital sections of oculoscapular canal with paired poreλ. A single poreκin near rear of interorbital region. Poreωpresent near dorsal side of posterior to eye. Lateral section of anterior oculoscapular canal with poreα and terminal poreρ. Posterior oculoscapular canal with two terminal poresθandτ. Preopercular canal with three poresγ, δ and ε.

Sensory papillae: Row a extending to vertical midline of orbit. Row b longer than a half of orbit. Rows c, d longer. A single cp papilla. Row f paired. Anterior edge of row oi connected to lower region of row ot.

Colouration of fresh preserved material

Body light brown to yellowish brown. Side of body with 6-7 major patches of irregularly grayish to brownish black marks in male, with distal deep brown edge on scale pockets in female. Dorsal region of body with about 5 major grayish blotches. Caudal fin base with a short deep brown bar. Head blackish brown to yellowish brown. Dorsal side of snout with a pair of bright red stripes united to snout tip, another gray stripe or bar below eye. Lips and dorsal snout yellowish orange to orange brown. Cheek blackish brown with four oblique grayish black stripes in male but yellowish brown spotless in female. Branchiostegal membrane grayish blue without any light spots in male, and pale brown and also spotless in female.

First dorsal fin broad grayish brown band wider and darkening in middle, outer margin orange in male, but translucent with brown spinous rays and distal orange yellow mark in female. Second dorsal fin with grayish black background and three to four basal longitudinal rows of deep brown spots in male; but translucent or gray with four to five basal longitudinal deep brown spots and grayish black margin in female. Anal fin orange with distal gray to black margin in male, but translucent with deep brown lines in female. Pectoral fin gray with basal creamy yellow band and its base with longitudinal deep brown bar in upper part and a vertical light brown bar in lower part in male; but translucent and its base with longitudinal deep brown mark and a vertical light brown bar in female. Caudal fin gray with four vertical rows of brown spots in male, but translucent or pale with 4-5 vertical rows of brown spots in female. Pelvic fin gray in male; but whitish in female.

Etymology.

The specific name, lingtongyanensis , refers to the collecting type locality: the small hill-stream in Dongshi river basin near the “Lingtongyan” mountain, Darshi township, Shaoan County, Janchou City, Fujian Province, China.

Distribution.

This new species is, thus far, only found in the small tributary of Dongshi basin near Shar village near the “Lingtongyan” mountain, Darshi township, Shaoan County, Janchou City, Fujian, China. It occurs in shallow-water riffles and front region of pools (depth 20-50 cm depth) with substratum of medium to large pebbles with moderate to fast flowing water.

Remarks.

The new species, R. lingtongyanensis , is rather similar to R. longyanensis Chen et al. 2008 than any other 6 congeneric fluvial species in Fujian Province by overall colouration pattern in male. However, R. lingtongyanensis can be well distinguished from R. longyanensis by the following features: (1) pectoral fin rays: 15-16 (modally 16) vs. 17-18 (modally 17); (2) longitudinal scale rows: 25-27 (modally 25) vs. 30-32 (modally 30); (3) vertebral count: 26 vs. 27; (4) cheek pattern: at least four main oblique black lines vs. three oblique black line in male; and (5) branchiostegal membrane: spotless vs. several red spots in male.

Figures

FIGURE 1. Head lateral-line system of Rhinogobius lingtongyanensis, new species, male, holotype, 30.8 mm SL, the Dongshi river basin, Fujian Province, PR China.

FIGURE 2. Rhinogobius lingtongyanensis, n. sp., a, male, holotype, 30.8 mm SL; b, female, paratype, 38.5 mm SL, the Dongshi river basin, Fujian Province, PR China.

FIGURE 3. Ventral view of Rhinogobius lingtongyanensis, n. sp., with spotless branchiostegal membrane in male, holotype, 30.8 mm SL, the Dongshi river basin, Fujian Province, PR China.