Effect of Larval Ages and Honey Treatment on the Sex Reversal of Betta Fish (Betta splendens).

<b>Background and Objective:</b> Betta fish is one of the most popular ornamental fish because of their attractive body shape, especially for males. The fish development usually results in a similar number of males and females or an even higher number of females. This study aimed to determine the effect of various concentrations of honey and the age of larvae on the sex ratio of Betta fish. <b>Materials and Methods:</b> This study was conducted using a completely randomized design with two variables; the concentrations of honey and the ages of Betta fish larvae in 3 replications. There are 45 groups in total with 20 larvae in each group. The levels of honey concentration were 0 (control), 10, 20, 30 and 40 mL/L and the levels of larval ages were 3, 4 and 5 days old. All groups were immersed for 10 hrs in the honey mix and then maintained for 4 months. Sex ratio calculation was performed after 3 months. <b>Results:</b> The both factors have a significant effect on male sex formation. The highest number of males was produced in the honey concentration of 40 mL/L. A significant difference in the number of males was shown in the larval group of ages 3 and 4 days old but not in the groups of 5 days old. <b>Conclusion:</b> Honey treatment and the larval age affect the formation of male Betta fish.