Abstract:
From 2022 to 2023, we conducted a survey on the growth characteristics and natural mortality coefficients of
Rhinogobio cylindricus in the upper reaches of the Yangtze River and compared these findings with those data before the ten-year fishing ban to analyze its impact and effectiveness. The results showed that 417
Rhinogobio cylindricus were collected in the Hejiang and Mudong reaches of the upper Yangtze River. Fish with body lengths of 200—250 mm accounted for 45.56% of the sample, while those with body weights of 100—200 g accounted for 49.88%. The relationship between body length and body weight was
W=8.02×10
–6L3.083, showing positive anisotropic growth. Among these, scales from 285 individuals were analyzed for age identification, revealing an age range of 1—7 years, with 3-year-old individuals comprising the largest group at 50.18%. Growth analysis showed that
Lt= 379.941–e
–0.19(t+1.59) and
Wt=720.351–e
–0.19(t+1.59)3.083(
R2=0.867,
n=285), with an apparent growth index of 4.44 and a mean natural mortality coefficient of 0.30. Comparative analysis with the pre-fishing ban showed that after the fishing ban, individual size of
Rhinogobio cylindricus in all age groups increased, growth conditions improved significantly, and natural mortality decreased, indicating a substantial positive effect on the growth of the fish and the recovery of the population resources. In order to further protect the
Rhinogobio cylindricus population in the context of the 10-year fishing ban in the Yangtze River, we recommended to strengthen the monitoring and research on the life history process, spawning grounds, and habitat conditions of the
Rhinogobio cylindricus. Conservation and restoration of important habitats, such as riverbanks, are essential for supporting population recovery and extending the benefits of the 10-year fishing ban in the Yangtze River.