Females of Chinese tongue sole (Cynoglossus semilaevis) grow 2-4 times faster and bigger than males, but some genetic females can sex reverse into phenotypic males (called pseudomales, ZW karyotype) that presents similar slow growth to normal males. Pseudomales could only produce Z-type sperm, of which the inheritance epigenetic pattern makes their offspring tend to be pseudomales. In this study, to explore the potential mechanism underlying sperm defect (W sperm absence) of pseudomales, we compared the proteomic profiles of pseudomale and male semen samples.