Length-weight relationships and condition factor of five endemic fish species from Nandu and Wanquan Rivers in Hainan Island, China

Abstract

Length-weight relationships LWRs , length-length relationships LLRs , and condition factor were estimated for Puntius semifasciolatus Gunther, 1868 , Acrossocheilus iridescens Nichols and Pope, 1927 , Plesiomyzon baotingensis Zheng and Chen, 1980 , Hemibagrus hainanensis Tchang, 1935 and Glyptothorax hainanensis Nichols and Pope, 1927 obtained from Nandu and Wanquan Rivers in Hainan Island during June 2017 to April 2019. Fish samples were collected by a combination of methods including multinet gillnets 20 m in length, 1.5 m in height, there monofilament panels of mesh sizes: 1.0, 6.0, 12.5 cm , benthic large bag nets 5 meters long, stretching mesh size: 0.5 cm . The LWRs and LLRs of all species studied were well correlated R$^{2}$ > 0.95 . The b values ranged from 2.8285 for H. hainanensis to 3.0815 for P. baotingensis. The 5 LWRs and LLRs are presented to FishBase for the first time. Additionally, condition factor of P. semifasciolatus, A. iridescens, P. baotingensis, H. hainanensis and G. hainanensis were severally 11.85 ± 1.34, 1.86 ± 0.18, 2.05 ± 0.28, 1.36 ± 0.33, and 2.02 ± 0.35, respectively. This study aims at facilitating fishery management or conservation by providing essential data for the regulation of catches and estimation of biomass in Nandu and Wanquan Rivers in Hainan Island.