Swimming ability of Diptychus maculatus Steindachner in the Muzati River for fishway design

In order to explore the swimming ability of Diptychus maculatus Steindachner, provide reliable parameters and data for the design of fish facilities and the study of fish swimming behavior, the swimming capability of wild D. maculatus Steindachner (total length TL=12-16 cm) from the Muzati River in Xinjiang was measured at (16.6±1.6) °C water temperature. Results showed that the induction velocity was (0.18±0.02) m/s relative induction velocity was (1.40±0.23) BL/s; the critical swimming speed was (1.02±0.15) m/s relative critical swimming speed was(8.58±1.65)BL/s; the burst swimming speed was (1.39±0.17) m/s relative burst swimming speed was (10.92±1.86) BL/s; the maximum sustained swimming speed was 0.87 m/s and the maximum prolonged swimming speed was 1.37 m/s, which was close to the average burst swimming speed. The swimming time was negatively related to swimming velocity(\lg T = - 5.136X + 8.504).When the target fish of fishway is D. maculatus Steindachner, it is recommended the flow rate at entrance should be from 1.02 to 1.39 m/s for attracting fish into the fishway, and the main flow rate in the rest pool should range from 0.20 to 1.02 m/s.The highest velocity in the fishway should be less than 0.85 m/s. When the length of the fishway is 1 000 m, the average water flow velocity in the fishway should be less than 0.78 m/s. This investigation provided a reference for the study of swimming capability of fish in the Xinjiang Muzhati River and is of great significance for the protection of endangered fish.