This has been observed in cichlid ®sh in areas
where the estrogen-mimic endosulfan has been sprayed
from the air for tsetse ¯y control (Matthiessen and Logan, 1984; Douthwaite et al., 1983).
The immediate consequences of exposure of ®sh to
estrogens and their mimics may thus be profound, altering the overt sexuality of the animal in many ways
and thereby damaging its ability to reproduce normally.