Hematology and recovery response in jacundá, Crenicichla saxatilis (Linnaeus, 1758) after short-term handling stress

Abstract

Summary The objective of this study was to evaluate the hematological response of ringtail pike cichlid ornamental fish (Crenicichla saxatilis) during the recovery period after short-term stress. The fish were previously submitted to the stress of chasing, capture and air exposure. Assayed were 24 C. saxatilis (85.2 ± 61.6 g) in three groups of eight fish; after 0.5, 6 and 24 h recovery, blood samples were collected. The total erythrocyte, relative thrombocyte and differential leukocyte counts as well as total hemoglobin, hematocrit, glucose, total plasma protein and the red blood cells (RBC) indices of mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and MCH concentration (MCHC) were determined. Stress responses were observed after 0.5 h, although hyperglycemia remained constant during the experiment. Total lymphocyte and hemoglobin values decreased after 0.5 h in the recovery period. An increase of neutrophils and monocytosis was observed after 0.5 and 6 h, respectively. The MCHC remained stable until after 0.5 h, then varied from this time forward. MCV, MCH and erythrocyte numbers oscillated throughout the experiment. Intense stress was observed in the studied C. saxatilis, with most hematological variables not returning to their initial levels after 24 h.