其他摘要：ABSTRACT Immersion of undifferentiated larval tilapia in high temperature and 17α-methyltestosterone (MT) cab increase the male ratio. However, the effectiveness of immersion in high temperature of water containing MT remains to be evaluated. The purposes of this study were: 1) evaluate the male ratio, growth, and survival of tilapia, and 2) analyze the aromatase brain-type gene expression level in tilapia after immersing in high temperature (36 °C) containing MT at 2 mg/L for four hour with single and double immersion. Aromatase gene expression was analyzed by semi-quantitative RT-PCR (sqRT-PCR) method. The result showed that higher monosex male ratio was obtained by single immersion of MT at 36 °C at room temperature. Gene expression level of aromatase brain-type was lower on single immersion and increased significantly at second immersion compared to control (immersion at room temperature without MT). Immersion using MT and high temperature had no significant effect on fish survival. However the specific growth rate and fish biomass were higher than control. Thus, monosex male tilapia can be produced by single immersion of undifferentiated larvae at 36 °C temperature containing MT.
