The male
phase of protandrous species such as the giant perch (Lates
calcarifer) (Fujii, 1971; Moore, 1979; Guiguen et al., 1994) and
the common snook (Centropomunus undecimalis) (Grier and
Taylor, 1998) have only testicular tissue in their gonads and sex
change from male to female is first evident with the appearance
of oocytes within the testicular tissue.