Comparative life-history analysis demonstrates consistent maturity-to-maximum-size ratios in Amazonian fishes, suggesting viable size-based catch thresholds for data-limited fisheries.
Effective management of tropical multispecies fisheries requires biologically grounded indicators that remain robust under data-limited conditions. This study evaluates the ratio between length at first sexual maturity (Lm) and maximum length (Lmax) as a comparative life-history metric for Amazonian fishes. Reproductive and biometric data from 123 commercially important species were compiled to assess variation in the Lm/Lmax ratio across geographic regions, habitat types, and life-history strategies. Although statistically significant regional differences were detected, values consistently clustered within a relatively narrow range, indicating functional convergence with bounded variability rather than strict invariance. This convergent pattern supports the use of the Lm/Lmax ratio as a heuristic reference for defining biologically meaningful size-based management thresholds for fisheries. By combining a lower limit based on maturity (Lm) with an upper limit for megaspawner protection (2/3 × Lmax + 10%), we propose the Target Capture Length (TCL) as an intermediate and operational reference point. The TCL framework translates life-history information into practical guidance for fisheries regulation, offering a simple and adaptable tool for improving sustainability in Amazonian fisheries under conditions of limited data availability.
No takes yet. Share an insight, caveat, or question.
Lozáno et al. (2026) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: