Age, Growth and Reproduction of Schizothorax pseudaksaiensis of the Turks River

The age, growth, and reproduction of Schizothorax pseudaksaiensis (Herzenstein, 1889), a second-level key protected aquatic species in Xinjiang, were studied using fish ecology methods, and the biological characteristics of its population are discussed. A total of 735 specimens were collected on a seasonal basis from 2021 to 2022 using cages and nets in the Turks River. The fish length ranged from 47.30 mm to 538.60 mm, and the minimum age and maximum age were 1 years old and 23 years old, respectively. The fitting correlations revealed that S. pseudaksaiensis is a uniformly growing fish. The ages at the inflection point for S. pseudaksaiensis were 22.28 (female) and 19.55 (male). The sex ratio was 0.89 (females):1 (males), and the spawning period occurred from April to July. The absolute fecundity was 55,652.01 ± 25,468.78 eggs per individual, and the relative fecundity was 25.92 ± 10.69 eggs per gram. This study provides life history trait data for S. pseudaksaiensis and has theoretical and practical importance for maintaining population dynamics and fishery ecological balance. Additionally, a basis for the protection of fishery germplasm plateau resources is provided.