ONTOGENETIC DEVELOPMENT OF SAGITTA OTOLITHS IN EUGERRES BRASILIANUS (CUVIER, 1830) (ACTINOPTERYGII: GERREIDAE) WITH EMPHASIS ON SIZE AT FIRST SEXUAL MATURITY IN A COASTAL LAGOON IN SOUTHEASTERN BRAZIL

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

Abstract

Otolith developmental assessments related to fish life history search to provide important information for understanding the intraspecific variability of these structures. In this context, the present work searched to identify ontogenetic and sexual patterns in the morphology of Eugerres brasilianus otoliths captured in Itaipu lagoon between July 2019 and April 2020. The size at first maturation (L50) was determined for the grouped and separate sexes. Wavelet coefficients and shape descriptors were evaluated by total length (TL) classes. While sexes and maturation stages were evaluated only by shape descriptors. A total of 158 specimens were captured between 7.5 and 30.6 cm TL, with a length at first maturation for grouped sexes of 15.5 cm TL, 15.3 cm TL for females and 15.5 cm TL for males. The wavelet coefficients showed significant differences between the TL classes (PERMANOVA; p<0.001). Significant differences were also observed for the shape descriptors for the TL classes, sexes and maturation stages (PERMANOVA; p<0.001). Our results confirm the hypothesis of ontogenetic variations in the morphology of E. brasilianus otoliths, which can be attributed to variations in habitat use, metabolism, condition and growth rates. While the differences between the otoliths of mature females and males, as well as between maturation stages, are reflections of the energy expenditure arising from gonadal development.

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