The Length–Weight Relationship in Food Fish Species From the Upper Putumayo River Basin, Colombia

The length–weight relationship (LWR) in fish is an important tool because it allows understanding aspects such as growth assessment, body condition, and biomass estimation. The aim of this study was to determine the LWR of food fish species from the Amazonian plain of the Putumayo River caught by artisanal fisheries to be sold in the town of Puerto Leguízamo between 2018 and 2023. More than 19,000 individuals of 31 species were registered. Each fish was taxonomically identified at the species level, recording its standard length (cm) and weight (g). Searches in FishBase revealed that six species lack referenced data, twenty five are not reported for the Putumayo Basin, and five are in the vulnerable category, according to the International Union for Conservation of Nature (IUCN). The relationship data calculated in this study are the first publications for these species in this region of the Amazon Basin. Knowledge of these biometric data and their relationships is relevant for managing and conserving fish and fisheries.