CHANGES IN ERYTHRON ORGANIZATION DURING PROLONGED CADMIUM EXPOSURE - AN INDICATOR OF HEAVY-METAL STRESS

Changes in erythron organization were examined in goldfish (Carassius auratus) exposed for 3 wk to 5, 15, and 25% of 240-h Cd LC50. In a sub sequent, more extended study, specimens were first rendered acutely an emic by immersion in phenylhydrazine HCl, allowed to recover in Cd-fre e water or in concentrations equivalent to approximately 5 or approxim ately 11% of LC50, and sampled after 2, 5, 8, and 11 wk. Total, dividi ng, and degrading or karyorrhectic cell numbers were recorded, as were cell length, one-sided surface area, and form factor. In fish exposed to approximately 11% LC50, total cell numbers and the incidence of ce ll division fell, while karyorrhexis increased. Dividing to total cell ratios declined with time; karyorrhectic to total and karyorrhectic t o dividing cell ratios increased. Variations in cytomorphology suggest ed slower cell maturation at both metal concentrations. Detection of h eavy metal stress in fishes by this form of hematological assessment a ppears feasible.