Weight Relationships of Three Cyprinid Fishes From

Home , Ptychobarbus, Schizopygopsis

Technical contribution Length-weight relationships of three cyprinid ﬁshes from headwater of the Nujiang River, China By D. K. He, W. Xiong, X. Y. Sui, Y. T. Jia and Y. F. Chen

Laboratory of Biological Invasion and Adaptive Evolution, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China

Summary S. nukiangensis are endemic to the upper reaches, and Length-weight relationships (LWR) for three cyprinid fish P. kaznakovi is endemic to the Tibetan Plateau, including the species collected from the headwaters of the Nujiang River upper Nujiang, Jinsha (the upper Yangtze) and Mekong riv- in Tibet, China, were determined. The values of parameter b ers (Yue, 2000). P. kaznakovi is listed in the ‘China Species in the LWR equations were estimated as 2.54 for Schizopyg- Red List’, and also listed as vulnerable in the ‘China Red – opsis thermalis, 3.3 for Ptychobarbus kaznakovi, and 2.74 for Data Book of Endangered Animals Pisces’ (Yue and Chen, Schizothorax nukiangensis, respectively. These are the first 1998; Wang and Xie, 2004). LWR records for the three species. All three schizothoracine fishes are benthic omnivores, but exhibit different feeding habits. The lower jaw of S. nukiangensis with a sharp horny edge is adapted to scraping off algae, detritus and benthic invertebrates, such as Cymbella, Introduction Naricula, Oligochaeta, chironomid larvae. P. kaznakovi pre- The ichthyofauna of freshwater systems of Southeast Asia is fer to consume aquatic insect larvae and benthic inverte- extremely diverse (Yap, 2002; Dudgeon, 2011). The Nujiang brates such as Limnodrilus, the larvae of Diptera and River (the Salween) is the second largest river in Southeast caddisflies, and with a minor addition of diatoms and detri- Asia, with 78 (26 endemic) fish species distributed therein (D. tus. S. thermalis feeds mainly on Oscillatoria, diatoms and K. He and Y. F. Chen, unpubl. data). Some recent studies detritus, followed by larvae of chironomid and Dipteran, have taken note of the impacts of hydroelectric power stations water beetles and crustaceans (Wu and Wu, 1992). In Tibet, in the upper Nujiang River (Dudgeon, 2005, 2011; Nilsson S. nukiangensis begins upstream reproductive migration with et al., 2005). However, the published data on the biological the rise in water temperature in April, and spawns mainly information of fish in this region has been limited to the man- from March to June. P. kaznakovi and S. thermalis breed agement and conservation of fish species in the basin. from April to May, and from April to August, respectively The ichthyofauna of the upper Nujiang River mainly com- (Wu and Wu, 1992). prises three groups of fishes: the schizothoracines (Cyprini- Some studies have focused on the molecular phylogeny of dae: Schizothoracinae), noemacheiline loaches (Balitoridae: these three fish species (He et al., 2004; He and Chen, 2006, Nemacheilinae), and the glyptosternoids (Sisoridae) (Chen 2007). However, no LWR information was available for et al., 1996). Three schizothoracine fishes (Schizopygopsis these species in FishBase. The aim of this study was to esti- thermalis Herzenstein, 1891, Ptychobarbus kaznakovi Nikol- mate the LWRs of these three schizothoracines from the skii, 1903, Schizothorax nukiangensis Tsao, 1964) are found upper Nujiang River. Our results are the first LWR informa- in the upper Nujiang River, Tibet. Of these, S. thermalis and tion on these three fish species.

Table 1 Descriptive statistics and LWR parameters for three ﬁsh species in upper Nujiang-Salween River, Tibet, China

Length Weight Family Species N range (cm) range (g) a 95%CL ab95%CL br2

Cyprinidae Schizopygopsis thermalis Herzenstein, 1891 39 5.4–32.5 2.4–364.0 0.0556 0.0138–0.0973 2.54 2.31–2.77 0.99 Ptychobarbus kaznakovi Nikolskii, 1903 51 21.4–57.5 71.0–1546.0 0.0023 0.0014–0.0032 3.3 3.2–3.4 0.97 Schizothorax nukiangensis Tsao, 1964 96 27.2–50.0 157.0–956.0 0.0208 0.0102–0.0314 2.74 2.60–2.88 0.96

N, number of individuals; Length range, total length range (cm); Weight range, total weight range (g); a and b, parameters of relationship; r2, coeﬃcient of determination; bold = new maximum total length record. 2 D. K. He et al.

Materials and methods for their assistance during the experiment. The research was Fishes were collected from headwaters of the Nujiang River supported by NSFC (41030208 and 31071900). (31.5446–31.5389 N; 92.8499–93.0715E) in Tibet, China. Fishes were caught by drift gillnet (stretched mesh size: References 4 cm) and castnet (mesh size 1 cm) in June and July of 2001–2004. All fishes were measured in the field as the total Chen, Y. Y.; Chen, Y. F.; Liu, H. Z., 1996: Studies on the position of the Qinghai-Xizang plateau region in zoogeographic divisions length to the nearest 0.1 mm and body weight to an accuracy and its eastern demarcation line. Acta Hydrobiol. Sin. 20,97– of 0.1 g. Most fishes were returned to the river, with only a 103 (in Chinese, English abstract). few preserved in 10% formalin. Dudgeon, D., 2005: River rehabilitation for conservation of fish bio- The LWRs were estimated using the equations: Log diversity in Monsoonal Asia. Ecol. Soc. 10, 15. = + Dudgeon, D., 2011: Asian river fishes in the anthropocene: threats W Log a b Log L, where W is the body weight (BW, g), and conservation challenges in an era of rapid environmental L is the total length (TL, cm), parameters a and b are the change. J. Fish Biol. 79, 1487–1524. regression parameters. The 95% confidence limits of parame- Froese, R., 2006: Cube law, condition factor and weight-length rela- ters (a and b) and coefficient of determination (statistical sig- tionships: history, meta-analysis and recommendations. J. Appl. – nificance level of r2) were determined, and all plots of Ln W Ichthyol. 22, 241 253. He, D. K.; Chen, Y. F., 2006: Biogeography and molecular phylog- and Ln L were made for each species to check for and eny of the genus Schizothorax (Teleostei: Cyprinidae) in China exclude outliers (Froese, 2006). inferred from cytochrome b sequences. J. Biogeogr. 33, 1448– 1460. He, D. K.; Chen, Y. F., 2007: Molecular phylogeny and biogeogra- Results phy of the highly specialized grade schizothoracine fishes (Teleo- stei: Cyprinidae) inferred from cytochrome b sequences. Chin. A total of 186 individuals belonging to three fish species were Sci. Bull. 56, 777–788. collected. Descriptive statistics on length and weight mea- He, D. K.; Chen, Y. F.; Chen, Y.Y.; Chen, Z. M., 2004: Molecular surements, sample sizes (n), regression parameters a and b of phylogeny of the specialized schizothoracine fish (Teleostei: Cyp- rinidae), with their implications for uplift of the Qinghai-Tibetan the LWRs, and their 95% confidence limits and coefficients – 2 Plateau. Chinese Sci. Bull. 49,39 48. of determination (r ) are given in Table 1. New maximum Nilsson, C.; Reidy, C. A.; Dynesius, M.; Revenga, C., 2005: Frag- lengths for two species are also given in Table 1. mentation and flow regulation of the world’s large river systems. Science 308, 405–408. Wang, S.; Xie, Y. (Eds.), 2004: China species red list. Higher Educa- Discussion tion Press, Beijing. Wu, Y. F.; Wu, C. Z., 1992: The fishes of the Qinghai-Xizang In our study, parameter b was determined as 2.54 for S. ther- Plateau. Sichuan Publishing House of Science & Technology, malis, 2.74 for S. nukiangensis, and 3.3 for P. kaznakovi, Chendu. respectively. The values of parameter b for all fish species Yap, S.Y., 2002: On the distibutional patterns of Southeast-East – remained within the accepted range of 2.5–3.5 (Froese, 2006). Asian freshwater fish and their history. J. Biogeogr. 29, 1187 1199. In conclusion, our study is the first record of LWRs for Yue, P. Q. (Ed.), 2000: Fauna Sinica: Osteichthyes Cypriniformes S. thermalis, P. kaznakovi and S. nukiangensis, which pro- III. Science Press, Beijing. vides basic information for subsequent research, management Yue, P. Q.; Chen, Y. Y. (Eds.), 1998: China red data book of endan- and conservation on fish resources in the upper reaches of gered animals. Science Press, Beijing. the Nujiang River. Author’s address: Yifeng Chen, Laboratory of Biological Invasion and Adaptive Evolution, Institute of Hydrobiology, Chinese Academy of Acknowledgements Sciences, Wuhan 430072, China. E-mail: [email protected] We thank Lei Juan, Liu Chunlong, Zhang Xi’ao, Liang Yangyang, Wei Chaojun, Li Chunhua, and Zhang Dengcheng