Inland fishing is an essential activity for the livelihood and food security the Colombian population. The knowledge and evaluation of exploited fish stocks is a priority to develop sustainable management and conservation strategies of the fisheries. To optimize the management processes of fishery resources and conservation of species, it is necessary to evaluate the population structure and identification of stocks. Geometric morphometrics analysis have shown useful in the evaluation of fish stocks. This study focuses on the species Plagioscion magdalenae, commonly called “Pacora”, corvinata, or river croaker, which belongs to the family Sciaenidae, a family characterized as an important fishery resource. With the aim of generating a baseline about the state of the P. magdalenae population structure, samples were collected along the marshy complex of the Dique channel, Colombia, between December 2020 and October 2021. In this study, the existence of morphometric variability between individuals of Plagioscion magdalenae was found across sampling sites, Ciénaga de Capote and Ciénaga del Jobo; shape differences between location suggest the action of environmental pressures and the existence of anthropogenic pressures, such as unsustainable artisanal fishing.

El desarrollo de estudios ecomorfológicos en peces permite reconocer y describir las relaciones presentes en los sistemas acuáticos, de manera que es posible comprender más claramente la interacción entre las características ambientales, morfológicas y ecológicas. Potamorhina laticeps (Characiformes: Curimatidae), es una especie endémica de la macrocuenca del Lago de Maracaibo que incluye el sistema fluvial del oriente colombiano, entre los que se encuentra la cuenca del Catatumbo; P. laticeps es una especie manejada comercialmente y para la subsistencia de las comunidades aledañas a la cuenca, principalmente en la región sur de Norte de Santander. Se examina la variabilidad morfológica de P. laticeps en dos ríos tributarios de la cuenca del Catatumbo, mediante morfometría geométrica (MG) y se identifican las principales asociaciones entre las características ambientales de los sitios de estudio y la morfología de sus poblaciones. Los resultados muestran una forma corporal relativamente conservada en la especie, lo que sugiere una alta estabilidad y eficiencia en el stock fenotípico de las poblaciones evaluadas. Se observaron ligeras variaciones entre sexos en ambas localidades, las cuales podrían estar asociadas a procesos reproductivos, estados de madurez gonadal o a la influencia de factores ambientales. Finalmente se reconoce la importancia de estudios que permitan comprender las características poblacionales y con ello la formulación de una línea base para el desarrollo de programas de conservación y manejo sostenible de la ictiofauna asociada a la cuenca.

Maintaining genetic diversity is essential for the long-term conservation of migratory freshwater fishes facing increasing anthropogenic pressures. Prochilodus magdalenae (bocachico), one of Colombia’s most economically and ecologically important freshwater fish species, supports artisanal fisheries, regional food security, and the livelihoods of local communities but has experienced population declines associated with overfishing, habitat degradation, and hydrological alteration. This study evaluated the genetic diversity and population structure of wild and hatchery-associated P. magdalenae from northern Colombia using sequence-based microsatellite genotyping (SSR-GBS). Sixty individuals (48 wild adults from three localities in the Department of Sucre and 12 hatchery-associated fingerlings from Cereté) were genotyped at seven polymorphic microsatellite loci. Wild populations retained high genetic diversity and exhibited weak but significant genetic differentiation (FST = 0.017, p = 0.003), with only 2% of the molecular variation distributed among populations and high estimated gene flow (Nm = 14.899). Hatchery-associated fingerlings consistently exhibited lower allelic richness while maintaining relatively high heterozygosity. Rarefied allelic richness did not differ significantly among populations (Kruskal–Wallis, p = 0.400); however, hatchery-associated fish consistently showed lower values, highlighting the value of allelic richness as a complementary indicator for evaluating hatchery-produced stocks. These findings provide a genetic baseline for the conservation of P. magdalenae and support incorporating routine genetic monitoring into supportive breeding and restocking programs.