Gonads of the sterile and control fish of all age groups were
immunohistochemically examined for 3b-HSD at the end of the
experiment. In the 9 dah-stage group, the gonads of both normal
and sterile fish had strong immunoreaction against 3b-HSD.
Control fish had positive immunoreaction in the interstitium and
theca cells, whereas sterile fish had immunopositive cells clustered