Metamorphosis is a rapid process and to meet the demands of a
new life form, blood cell populations are renewed (Hasebe et al.,
1999). The transition from larval to adult cells begins at the onset
of metamorphosis (Hasebe et al., 1999) with increased erythropoietic activity. In a response to the increased need for replacing larval
blood cells with adult cells, resulted in the dramatic increase in the
mitotic index following 200–400lgL
1
sodium arsenite treatment
(Fig. 2), which could act as a physiological marker of the onset of
metamorphosis.