High temperature induces cyp26b1 mRNA expression and delays meiotic initiation of germ cells by increasing cortisol levels during gonadal sex differentiation in Japanese flounder

► Sexually dimorphic expression of cyp26b1 was observed in Japanese flounder. ► High temperature upregulated cyp26b1 expression in gonads. ► High temperature delayed meiotic initiation of germ cells. ► Cortisol induced cyp26b1 expression and suppressed meiotic marker sycp3 expression.