Energy Metabolism, Ghrelin Levels and Personality Could Not Predict the Vulnerability of Qingbo (spinibarbus Sinensis) to Angling

Fish are often faced with selection pressure from human activities (e.g., fish angling). Therefore, morphological, physiological, personality, and life history characteristics have evolved directly in fish populations under this human-made selection. Here, we investigate the phenotypic basis of vulnerability to angling in juvenile Qingbo (Spinibarbus sinensis). The standard metabolic rate (SMR), maximum metabolic rate (MMR), and personality (i.e., exploration, activity and boldness) of juvenile S. sinensis were determined. An angling experiment was then conducted and the hormones (i.e., ghrelin) of the individuals were examined in a laboratory at 24.9 ± 0.1 °C. Our results showed that only frequency with which the fish touched the novel object in exploration was higher in the LVA (low vulnerability to angling) phenotype than the HVA (high vulnerability to angling) phenotype, but energy metabolism (SMR; MMR; AS, aerobic scope; FAS, factorial aerobic scope), hormone (ghrelin levels) and personality (exploration, activity and boldness) did not differ between the HVA and the LVA phenotype. Principal components analysis showed that exploration was associated with boldness while activity was not associated with boldness. The AS, exploration and boldness score were inhibitory factors for the HVA outcomes, but ghrelin, activity score and exploration score did not contribute to outcomes of the HVA. These results suggest that energy metabolism, hormone levels and personality are not predictors of vulnerability to angling in Qingbo under the laboratory condition, but individuals with higher tendency to explore the novel environment are more likely to be bolder.