Hematological recovery in Sparus aurata after bleeding. A time course study.

To determine the hematological recovery after blood loss in gilthead sea bream juveniles, an experimental anemia was induced by caudal blood extraction. Seventy fish were used for experimental hemorrhage and another 35 were used as controls. Blood samples were taken after 0.5, 1, 2, 4, 8, 16 and 32 days in both control and anemic groups. After bleeding, besides a reduction in the direct hematic constants, a peak in the mean cell volume value, together with a decrease in mean cell hemoglobin concentration after bleeding, suggested erythrocyte swelling. The increase in MCH suggested the occurrence of hyperchromic erythrocytes. Recovery of RBC number started between 2 and 4 days after bleeding and seemed to be related to erythroblast release to circulation. Total recovery was completed after 8 days of bleeding. The recovery patterns for hematological parameters of sea bream are discussed in relation to applied work on this species.