BEYOND THE AMAZON: FIRST SCIENTIFIC RECORD OF THE PIRARUCU ARAPAIMA GIGAS (SCHINZ, 1822) IN THE DOCE RIVER BASIN, SOUTHEASTERN BRAZIL

First record of the pirarucu in the Doce River basin

Abstract

Arapaima gigas is one of the largest Neotropical freshwater fish, native to the Amazon and Araguaia–Tocantins river basins, whose distribution has recently expanded beyond its natural range due to escapes from aquaculture tanks and recreational activities. In this study, we report the first occurrence of A. gigas in the Doce River basin, southeastern Brazil. The record is based on one juvenile collected in a lagoon in the state of Espírito Santo in January 2025. Species identification was confirmed using diagnostic morphological characters. This finding represents a new range expansion of the pirarucu, an alert of potential colonization, and, consequently, a threat to native fish populations. Considering the long history of non-native species introductions and environmental degradation in the Doce River basin, the presence of A. gigas highlights the importance of early detection and monitoring to support management actions and the conservation of native freshwater fish assemblages.