Pararasbora moltrechti Regan, 1908

Yeh, Ming-Fon, Jang-Liaw, Nian-Hong, Chang, Shih-Tsang, Han, Chiao-Chuan, Ho, Lin-Tai & Wang, Shen-Chih, 2024, Pararasbora moltrechti Regan, 1908, a senior synonym of Aphyocypris amnis Liao et al., 2011 (Teleostei: Cyprinidae) in Taiwan with morphological and molecular evidence, Zootaxa 5550 (1), pp. 271-277 : 272-275

Pararasbora moltrechti Regan, 1908

( Figs 1–6 )

Pararasbota moltrechti Regan, 1908: 360 (Lake Candidius—Sun Moon Lake, Taiwan); Chen & Fang, 1999: 82.

Aphyocypris amnis Liao et al., 2011: 658 ( Jusheui River basin, Taiwan).

Material examined

Lectotype. BMNH 1909.4.28.24 , 54.8 mm SL, coll. A. Moltrecht., Lake Candidius , Taiwan.

NMNSF000273 , 7 specimens, 38.6–55.4 mm SL, Dajar River basin, Shinsher County, Taichung, Coll. NH Jang-Liaw, 13 November 2003 .

NTOUP-2006-07-245 , 10 specimens, 43.6–68.5 mm SL, Wu River basin, Nantou County, Taiwan, N.H. Jang-Liaw et al., July, 2006 .

NTOUP-2007-05-303 , 14 specimens, 54.3–86.6 mm SL, Jushuei River basin, Nantou County, Taiwan, N.H. Jang-Liaw et al., May, 2007 .

Redescription

Dorsal fin 3+7; anal fin 3+7; pectoral fin 1+12–13; pelvic fin 1+7; gill racker modally 8; pharyngeal teeth 4, 4 – 4, 4; lateral fin scales 34–37; scales above lateral line 6–7; scales below lateral line 2; predorsal scale rows 19–20. No distinct difference between river basins.

Body elongate and compressed; a ventral keel extending from point of origin of pelvic fin to anus. All body proportion shown in Table 1 . No distinct morphometric differences between the population of Wu—Dajar river basins and population of Jushuei River basins.

Head rather wide and moderately large. Eye very large. Snout rather short. Maxillary rather oblique, extending just beyond vertical of orbit. No barbel. Body with moderate cycloid scales. Dorsal fin origin closer to caudal fin base rather than snout. Dorsal and anal fin origin with larger anterior rays. Caudal fin forked.

Coloration when alive

Body brownish gray dorsally and mainly sliver laterally with some golden tone. Belly silver to white. Body scattered with vertical, small grayish black marks concentrating more densely in front of rear tip of anal fin base. Eye with a grayish region above pupil. Dorsal and anal fins grayish with somewhat pinkish to orange tones. Caudal fin generally grayish with pinkish centrally.

There are no distinct differences in coloration of specimens around these three different river basins in Taiwan.

Distribution

The species can be found in three main basins: The Dajar River basin, Wu River basin, and Jushuei River basin in Taiwan ( Chen & Fang, 1999; Chen & Chang, 2005). It is an endemic species of Taiwan. However, some fish populations have been released and introduced into the Lanyang River basin, Ilan county, potentially seriously threatening and causing the degradation of the native population of Aphyocypris kikuchii .

Figures

FIGURE 1. Lectotype of Pararasbora moltrechti, 54.8 mm SL, Lake Candidius, Nantou (Photo by I-Shiung Chen).

FIGURE 2. Pararasbora moltrechti from Jushuei River basin, Nantou, Taiwan, 55.2 mm SL.

FIGURE 3. Pararasbora moltrechti from Jushuei River basin, Nantou, Taiwan, 64.3 mm SL.

FIGURE 4. Pararasbora moltrechti from Jushuei River basin, Nantou, Taiwan, 70.8 mm SL.

FIGURE 5. Pararasbora moltrechti from Jushuei River basin, Nantou, Taiwan, 78.3 mm SL.

FIGURE 6. Pararasbora moltrechti from Wu River basin, Nantou, Taiwan, about 75 mm SL.