MOVEMENT PATTERNS OF SCHIZOTHORAX WANGCHIACHI IN THE LOWER REACHES OF THE HEISHUI RIVER BASED ON ACOUSTIC TELEMETRY

This study investigated the movement patterns of <italic>Schizothorax wangchiachii</italic> in the Heishui River using acoustic telemetry from November 26, 2024 to April 1, 2025. A total of 28 individuals were tagged and released at three sites—Datong (DT), Tangjiaping (TJP), and Zhuanbao (ZB)—with 18 acoustic receivers deployed. During the study, 321397 valid signals were recorded, each fish detected by an average of 4.8 receivers for 1—126 days. Spatial utilization differed significantly among release sites. The ZB group exhibited the largest activity range (50% KUD: 4.37 km²; 95% KUD: 26.96 km²; MCP: 14.62 km²), significantly greater than those of TJP and DT. The TJP group showed intermediate, river-aligned activity, while DT group remained most localized near the river mouth. Displacement rates also differed significantly (Kruskal-Wallis, <italic>P</italic>&lt;0.05), with DT lower than TJP and ZB, and TJP higher than ZB. Retention index (RI) declined over time in DT and ZB but increased in TJP, reaching 0.95—1.0 in March. Overall, released fish initially exhibited short-term exploratory movements around release sites, then gradually migrated beyond the array, with some entering the Heishui or Jinsha rivers. These results provide key insights for life-history studies and stock enhancement strategies for <italic>S. wangchiachii</italic> in the Heishui River.