Interaction Between Temperature and Propolis In Producing Male Guppy (Poecilia reticulata) Populations
Temperature-dependent sex determination has been demonstrated in some species of fish, and high temperature during the period of sex differentiation typically produces a male – dominant population. Propolis contains chrysin and galangin, as flavonoid compounds, their function is to inhibit conversion of androgen to estrogen. In the present study we investigated the effect of rearing temperature (T), propolis concentration (PC) and their interaction effect (TxPC) to the pregnant guppy (Poecilia reticulata), which is an ovoviviparous species. The treatments were given on the pregnant guppy for 24 hours, that were immersed at different temperature (28, 30 and 32oC) exposed for different concentrations of propolis (0, 25,
75 and 100 µL/L). Immersion used a glass tank with density 3 fish/L. After that they were moved to aquarium sized 30 x 20 x 30 cm3 for two months until the gonad could be analyzed. The result showed that effect of T and PC not significantly influenced on the sex, survival rate, final length, final weight and intersex (P>0.05). However, their interaction influenced sex (P<0.05). Increased percent male was observed with increasing the temperature and decreasing the propolis concentration. The highest percent male of 68.72% was obtained at 32oC T at 25µL/L PC. The treatments do not stimulate the intersex populations (P>0.05).