ESTIMATION OF BIOLOGICAL PARAMETERS OF HEMIBAGRUS HAINANENSIS IN THE UPPER NANDU RIVER

Hemibagrus hainanensis is a rare, endemic fish species in inland waters of Hainan. There is very little information about its basic biology in this region. A total of 358 fish samples were caught from the upper Nandu River from January to December 2019. The body length of H. hainanensis ranged from 42 to 289 mm, and weighed between 1.14 and 282.79 g. Moreover, the population parameters of H. hainanensis were estimated by ELEFAN I in FiSAT Ⅱ software, and the population dynamics was analyzed by the Beverton-Holt dynamic model. The estimated results of von Bertalanffy growth equation was L_∞=304.5 mm, K=0.49/year, and t₀= –0.29. The age inflection point of H. hainanensis was 1.95 years, while the body length was 202.9 mm. Natural mortality was 1.05/year using the empirical formula proposed by Pauly. The fishing (F) and total mortality (Z) coefficients were 0.17 and 1.22/year based on length-converted catch curve method, respectively. The exploitation rate (E) was 0.14, indicating a minimal fishing effect. It is the first time to explore the population growth and dynamic characteristics of H. hainanensis in the upper Nandu River, and this finding would provide a theoretical basis for the recovery and conservation of its population.