Aquaculture environment changes fish behavioral adaptability directly or indirectly through personality traits: a case study

The expansion of the scale of the aquaculture industry is one significant characteristic of global changes. However, the effects of the husbandry environment on fish phenotypic plasticity especially on fish behavioral adaptability got less attention. Moreover, whether fish boldness and brain neurogenesis mediate the environmental effects on fish behaviors was not clear. In this study, a batch of natural and husbandry rockfish Sebastes schlegelii were sampled, and the boldness, behavioral adaptability, and neurogenesis molecular markers of these fish were determined. Generally, our results showed that husbandry fish had significantly more sheltering behavior (MANOVA, P = 0.009), risk-taking behavior (MANOVA, P = 0.037), time duration spent to launch predatory behavior (MANOVA, P = 0.015), and higher fish boldness (MANOVA, P < 0.001) compared to natural fish, and meanwhile bold fish presented significantly more risk-taking behavior (LMM, P < 0.001), and less sheltering behavior (LMM, P = 0.05), flexible behavior (LMM, P = 0.022), and time duration spent to launch predatory behavior (LMM, P = 0.019) compared to shy fish. Overall, boldness almost had no effects on any neurogenesis processes, and meanwhile, environmental effects were also very limited (LMM, all P > 0.05). The structural equation model showed that the environmental effects on behavioral capacities were direct, indirect, or both direct and indirect (global goodness-of-fit: Fisher’s C = 18.672, P = 0.097), which were the trade-offs between survival environment and fish boldness. These results provide novel and fundamental knowledge for improving the ecological fitness of husbandry fish in biodiversity protection under the background of global environmental changes and urbanization.