Aspectos gonadais, perfil de testosterona e estradiol da tainha Lebranche Mugil liza submetida a diferentes temperaturas durante a fase de larvicultura

In Brazil, the Lebranche mullet is the most important Mugilidae species for the fishingindustry. However, recently, the species has been recommended for classification as near threatened.In this sense, aquaculture has emerged as a powerful tool for natural resource conservation anddevelopment. The present study evaluated the influence of different temperatures during Mugil lizalarviculture and their late effects on gonadal development and hormonal quantification after 24months. The fertilized eggs (45 eggs L-1) were initially kept in a 60 L circular tank until hatching. Afterhatching, the larvae were subjected to four treatments in triplicate at different temperatures (21,24, 27 and 30 °C) for 35 days. The juveniles were subsequently transferred to growth units wherethey remained identified, according to the treatments, for 24 months. The weight and length of thefish were significantly different in the larviculture phase. Histological analyses revealed immature,maturing, and mature male gonads. The estradiol levels in the fish were low, regardless of thematuration stage. For testosterone, the highest values were observed in mature males (1.29 ± 0.07ng mL-1). No significant differences were observed (p > 0.05) in the concentrations of estradiol andtestosterone in relation to temperature. However, there were significant differences (p < 0.05) intestosterone concentration depending on sexual maturation. The results suggest that temperatureexerts a masculinizing effect on M. liza. Furthermore, temperature directly affected larval growth. Insummary, the results provide evidence that temperature may play a crucial role in sex determinationin M. liza.