Análise biométrica dos crustáceos decapodos (dulcicolas) coletados no rio negro, na região do município de Barcelos–Am

Abstract

This study aimed to perform a biometric analysis of freshwater decapod crustaceans (infraorders Caridea and Brachyura) collected from the Negro River, near the municipality of Barcelos, in the state of Amazonas, Brazil. Specimens were collected bimonthly between August 2023 and July 2024, covering different hydrological periods of the region. Active sampling was conducted in selected tributaries, and the specimens were later analyzed in the laboratory for taxonomic identification, biometric measurements, and sex ratio assessment. A total of 123 individuals were collected, including 116 shrimps (Caridea) from 10 species and 7 crabs (Brachyura) from 5 different species. Measurements of carapace length and width revealed morphological variations between sexes and among specimens from different aquatic environments (lentic and lotic). Most of the analyzed species are classified as “Least Concern” (LC) according to the Red Book of Brazilian Crustaceans, while four species were listed as “Data Deficient” (DD). The results contribute to the expansion of knowledge regarding the Amazonian crustacean fauna, especially in a poorly studied and ecologically important area such as the Negro River. The information obtained can support future management and conservation efforts and fill knowledge gaps related to the biology and geographical distribution of the studied species.