Biologia e crescimento da Tainha (Mugil cephalus Linnaeus, 1758), acessível à pesca artesanal no estuário do rio dos Bons Sinais, Zambézia

Abstract

The limited availability of information regarding the biology and growth of the mullet (Mugil cephalus), coupled with its socioeconomic importance as bycatch for shrimp by artisanal fishing fleets, motivated this research. The objective was to analyze the population structure, the sex ratio of males and females, and determine the weight-length relationship. The research was based on monthly samples collected at several points along the Bons Sinais Estuary, Zambézia. Data were collected in May and October 2023. Individuals were sexually identified and differentiated between males and females. The main analyses focused solely on population structure, sex ratio, and the weight-length relationship. In total, approximately 184 individuals of Mugil cephalus were analyzed, of which 96 (52.17%) were females and 88 (47.83%) were males, with a length variation from 7.40 cm to 24.00 cm and total weights from 4.51 g to 98.72 g. A male-to-female sex ratio of 1 to 1 (1:1) was observed. This male-to-female ratio was analyzed using the chi-square test (X2), which also found no statistically significant differences (p<0.05) from the expected 1:1 ratio. Regarding growth type, the data reveal that the Mugil cephalus species exhibits negative allometric growth, both for grouped and separate sexes. Statistical tests of b values ​​also showed that there is no sexual dimorphism between males and females (p < 0.05).