Among Bagre genera, there is a high variation in the estimation of age, a concern due to overexploitation risk in fisheries because of age underestimation. Bagre panamensis is an important fishery resource of the Mexican Pacific and the Gulf of California. Its age is known from otoliths, but its accuracy needs to be confirmed, and the periodicity of the otoliths record validated. The external morphology, some microstructure attributes, and age record of B. panamensis' otoliths were described from 371 specimens collected southeast of the Gulf of California. The lapilli otoliths were larger than the sagittae and asterisci otoliths. The lapilli otoliths present aragonite crystals with a prismatic shape, and their growth is radial, from the core to the otolith edge. The lapilli otoliths form an annual growth ring, defined by the slowdown in the growth that occurs during April to July, during the breeding season. The ages of the individuals ranged from 1 to 15 years, and the applied method is considered adequate and accurate for its estimation (otolith cross-sectioning and red-neutral staining).

Fishing is a beneficial activity for populations settled near bodies of water. It can be split into industrial and artisanal fishing; the latter is more important from global, cultural, economic, and social points of view. Mugilids are of great commercial interest for artisanal fisheries due to their wide distribution and diverse uses; in Mexico, this resource stands out because it ranks fourth in the specific composition of catches and has shown a growing trend in yields in recent years (2008-2020). Therefore, an evaluation of the stock and behavior of the fisheries were undertaken in support of resource sustainability. We suggest that an active regulation measure be taken along with already existing passive measures. The exploitable biomass was estimated at 12,040 t, BMSY=11,424 t, and MSY=2,900 t. The resource is in decline with a tendency to overexploitation, and it could collapse if no action is taken. Therefore, we propose incorporating a temporal ban and an annual catch quota of 2,900 t to the current regulation, as well as using the methods and parameterization in this study for future evaluations.