Isotopic profile of the fauna associated with the inner estuary of the Paraíba do Sul River, northern Rio de Janeiro state, Southeaster Brazil

Abstract

This study characterizes the isotopic profile of nitrogen (δ¹⁵N) and carbon (δ¹³C) of crustaceans (Callinectes bocourti and Macrobrachium acanthurus) and fish (Lycengraulis grossidens, Anchoviella lepidentostole, Leporinus copelandii, Genidens genidens and Centropomus undecimalis) from the fauna associated with the inner estuary of the Paraíba do Sul River. ANOVA demonstrated significant differences among species regard to the nitrogen (F = 38.2, gl = 6, p <0.0001) and carbon (F = 24.3, gl = 6, p <0.0001) isotopic profile. Genidens genidens stands out from the other species with the heaviest values ​​of δ¹⁵N and δ¹³C, while M. acanthurus presented the lightest values ​​for both isotopes. The δ¹⁵N values ​​allowed to group C. bocourti, M. acanthurus, A. lepidentostole and L. copelandii with the lightest values, followed by L. grossidens and C. undecimalis, and then G. genidens, highlighted from the other species with the heavier δ¹⁵N. In relation to δ¹³C, the lightest values ​​refer to the group formed by M. acanthurus, L. copelandii and C. undecimalis, then C. bocourti with intermediate value, and L. grossidens, A. lepidentostole and G. genidens with heavier δ¹³C values. The data from this study are the first records of the isotopic profile of these animals for the region and will serve as a reference for future studies.