Freshwater ecosystems in arid and semi-arid regions are increasingly threatened by multiple anthropogenic stressors and climate-driven temperature rise. Understanding how these stressors affect native fish species is critical for prioritizing conservation efforts and developing targeted mitigation strategies. This study investigated the stressor-specific impacts on Carasobarbus fritschii, an endemic cyprinid of North African freshwater systems, by integrating behavioral assays and stress-related gene expression analyses to inform conservation in vulnerable habitats. Sixty fish were allocated to ten treatment groups (n = 18 per group; 6 fish & times; 3 independent biological replicates) and exposed to pyriproxyfen, elevated salinity, or thermal stress. Behavioral responses were quantified using automated video tracking over 30-minute observation periods, and muscle tissue samples were analyzed for the expression of heat shock protein 70 (HSP70), glucocorticoid receptor (NR3C1), nicotinic acetylcholine receptor alpha-7 (CHRNA7), and dopamine receptor D2 (DRD2) via RT-qPCR. Pyriproxyfen exposure induced a marked increase in locomotor activity (mean speed: 16.19 cm/s). Thermal stress enhanced exploratory behavior and promoted social aggregation (mean neighbors: 1.45), while eliciting the most pronounced molecular response: a 3-fold upregulation of NR3C1 at 36 degrees C accompanied by consistent HSP70 upregulation across elevated temperature treatments. Salinity stress produced complex, multi-target modulation, including HSP70 upregulation, a biphasic NR3C1 response, CHRNA7 downregulation at higher salinities, and shifts in spatial distribution toward light zone occupancy. Together, the behavioral and molecular biomarker profiles revealed mechanistic signatures characteristic of each stressor. These findings underscore the differential vulnerability of endemic cyprinids to distinct anthropogenic pressures and highlight the value of stressorspecific, multi-biomarker frameworks for freshwater biodiversity conservation.