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 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.