J Appl Ichthyol. 2019;1–3. wileyonlinelibrary.com/journal/jai | 1 © 2019 Blackwell Verlag GmbH 1 | INTRODUCTION The length–weight relationship (LWR) is an important parameter used in fishery research (Froese, 2006; Jin, Yan, Zhang, & Fan, 2015). LWR can be applied to estimate biomass, condition factor, and growth patterns of fish species. For a given fish species, LWR can be used to estimate an individual approximate weight when only length have been measured (Mousavi, Heidari, Mohammadi, Mansouri, & Ghasemzadeh, 2016). This study aimed to provide basic biological data on LWRs of five fish species sampled in the Beijiang River, China. For Ancherythroculter lini, Spinibarbus hollandi, Acrossocheilus beijiangensis and Parasinilabeo assimilis, no LWR data was yet avail‐ able in the FishBase database. 2 | MATERIALS AND METHODS The Beijiang River (23°09′25′′–25°21′47′′N; 112°49′13′′– 114°38′37′′E) (Zhu, Li, Li, & Wu, 2016), with a runoff volume of 4.82 × 10 10 m 3 /year, is the second largest branch of the Pearl River, South China (Chen et al., 2009). It covers a region of the subtropical zone with an area of about 46,480 km 2 (Pan, 1987). Received: 5 November 2018 | Revised: 3 December 2018 | Accepted: 13 December 2018 DOI: 10.1111/jai.13862 ORIGINAL ARTICLE Length–weight relationships of five fish species from the Beijiang River, China Tianxu Kuang 1 | Huiting Ruan 1 | Jiage Dai 1 | Yifei Lin 1 | Weiyuan Chen 1 | Yusen Li 2 | Han Lai 3,4 | Li Liu 1,5 | Lei Zhou 1,5 1 Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, South China Agricultural University, Guangzhou, China 2 Guangxi Key Laboratory of Aquatic Genetic Breeding and Healthy Aquaculture, Guangxi Academy of Fishery Sciences, Nanning, China 3 Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat‐Sen University, Guangzhou, China 4 South China Sea Bio‐Resource Exploitation and Utilization Collaborative Innovation Center, Sun Yat‐Sen University, Guangzhou, China 5 College of Marine Sciences, South China Agriculture University, Guangzhou, China Correspondence Lei Zhou and Li Liu, College of Marine Sciences, South China Agriculture University, Guangzhou, China. Emails: zhoulei@scau.edu.cn; liuli@scau. edu.cn Funding information The National Natural Science Foundation of China (Grant No. 41806170); Guangxi Science and Technology Major Project (Grant No. AA17204095‐8). Summary The length–weight relationships (LWRs) were determined for five fish species from the Beijiang River in China. Fishes were caught by gill nets (mesh sizes: 5, 7, 9 cm), and cage nets (mesh sizes: 0.5 cm) from April to September 2018. Length–weight rela‐ tionships of four species were unknown to FishBase, and new records of maximum lengths are given for two species, one of which, Ancherythroculter lini, is endemic species of the Pearl River. All length–weight relationships were highly significant on a log scale with the coefficient of determination (r 2 ) values ranged from 0.939 to 0.991. Values of b were within the expected range, varied from 2.935 for A. lini to 3.414 for Parasinilabeo assimilis.