HEMATOLOGICAL CHARACTERIZATION OF GOLDFISH, CARASSIUS-AURATUS L, BY IMAGE-ANALYSIS - EFFECTS OF THERMAL-ACCLIMATION AND HEAT-SHOCK

The morphological characteristics of erythrocyte populations from goldfish, Carassius auratus L., acclimated to constant (15, 25, or 35-degrees-C) and diurnally cycling (25 +/- 10-degrees-C) temperature regimes or exposed to abrupt heat shock (15-25-degrees-C, 25-35-degrees-C) were examined by image analysis in an attempt to develop criteria for assessing the stage of development and red cell population age structure. Of the indices considered, nuclear form factor (4-pi area/perimeter2) appeared to best define the immature state. Estimates of juvenile cell abundances based on nuclear form factor ranged from 23.2 to 56.5% of the cell population and were generally consistent with the thermal histories of the test groups examined. Erythrocyte population characterization is recommended for inclusion in future studies on hematological features of response to altered environmental conditions.