ERYTHRODYNAMICS IN FISH - RECOVERY OF THE GOLDFISH CARASSIUS-AURATUS FROM ACUTE ANEMIA

Goldfish (Carassius auratus) were rendered anemic through immersion in phenylhydrazine . HCl, a cohort of [H-3]thymidine-labelled erythrocytes was established, and recovery followed over a 234-d period. Red blood cell (RBC), hemoglobin (Hb), and hematocrit (Hct) levels increased in biphasic fashion during recovery, rapid increases to plateau values being followed by more modest increases to levels equalling those observed prior to treatment. During the initial rapid phase of response, increased ventilatory and cardiovascular activities probably compensated for deficits in oxygen-carrying capacity but, by elevating blood O-2 tension, may have suppressed erythropoiesis. Continuing slow increases in RBC, Hb, and Hct may point to some as yet unidentified alternative mechanism for stimulating red cell formation. During maturation, mean erythrocytic volume decreased, while mean erythrocytic hemoglobin level increased. Cycles of division of circulating juvenile erythrocytes occurred at roughly 56-d intervals, but did not appear to play a major role in elevating blood O-2-carrying capacity. Division and karyorrhexis or cell breakdown were loosely correlated. Under the conditions employed, red cell half-life was approximately 80 d.