DESENVOLVIMENTO ONTOGENÉTICO DOS OTÓLITOS SAGITTA DE EUGERRES BRASILIANUS (CUVIER, 1830) (ACTINOPTERYGII: GERREIDAE) COM ÊNFASE NO TAMANHO DE PRIMEIRA MATURAÇÃO SEXUAL EM UMA LAGOA COSTEIRA, NO SUDESTE DO BRASIL

Ontogenetic development of sagitta otoliths of Eugerres brasilianus (Cuvier, 1830) (Actinopterygii: Gerreidae) with emphasis on size at first sexual maturation in a coastal lagoon in southeastern Brazil

Abstract

Otolith developmental assessments contribute valuable insights into fish life history research, providing crucial information for understanding intraspecific variability of these structures. In this study, we aimed to identify ontogenetic and sexual patterns in the morphology of Eugerres brasilianus otoliths collected from Itaipu lagoon between July 2019 and April 2020. Size at first maturation (L₅₀) was determined for combined sexes as well as separately for females and males. Wavelet coefficients and shape descriptors were evaluated across total length (TL) classes , whereas shape descriptors alone were used to assess sexes and maturation stages. A total of 158 specimens ranging from 7.5 to 30.6 cm TL were examined, with a length at first maturation of 15.5 cm TL for combined sexes, 15.3 cm TL for females and 15.5 cm TL for males. Wavelet coefficients exhibited significant differences across TL classes (PERANOVA; p<0.001), as did shape descriptors acrossthe TL classes, sexes and maturation stages (PERMANOVA; p<0.001). Our findings support the hypothesis of ontogenetic variations in E. brasilianus otolith morphology, likely influenced by habitat use, metabolism, condition, and growth rates. Additionally, differences observed between otoliths of mature females and males, and among maturation stages, likely reflect varying energy expenditures associated withgonadal development.

Keywords: Carapeba, otolith shape, wavelet analysis, multivariate analysis.