The effects of ichthyophthiriasis on some haematological parameters in common carp

Abstract

The present study examined the haematological effects of ichthyophthiriasis in common carp. Blood was collected from 4 groups of juvenile carp: 1. healthy, 2. with minor symptoms of ichthyophthiriasis; 3. with severe symptoms of ichthyophthiriasis (moribund); survivors of ichthyophthiriasis after a 3-week recovery period. Blood was subjected to a standard haematological procedure and the following parameters were evaluated: haematocrit (Ht), haemoglobin concentration (Hb), erythrocyte (RBC) and leukocyte (WBC) counts, mean cell volume (MCV), mean cell haemoglobin (MCH), and mean cell haemoglobin concentration (MCHC). The differential leukocyte count and thrombocyte count were calculated using stained blood smears. No change in Ht or Hb, but a significant decrease in RBC compensated by an increase in MCV and MCH were observed. Fish with minor symptoms of disease had a significant increase in WBC (167.4 × 103/μL) without an alteration in the differential count, as compared to the controls (93.3 × 103/μL), while those with severe symptoms had a significant decrease in WBC (48.4 × 103/μL) accompanied by lymphopenia, and an increase in neutrophil and monocyte contribution. After 3 weeks of recovery WBC returned to a level similar to that in the controls (89.5 × 103/μL). In all the parasite-infested fish metabolic activity of phagocytes was significantly reduced, as compared to the controls. In the fish with severe symptoms of disease thrombocytosis and hypercoagulability were observed. © TÜBİTAK.