(a) Instantaneous total mortality coefficients (Z) of Umrbrina canosai aged 3 to 10 yr, fished along southern Brazil and their 95% credibility intervals. (b) Exploitation rates considering a natural mortalities of 0.248 yr⁻¹ (lower values) and 0.161 yr⁻¹ (higher values). (c) Natural logarithms of relative frequencies at age per year classes in ten sampling periods between 1976 and 2019.