To determine the effects of anesthesia to clove oil on the secondary stress indices, changes in haematological and blood chemistry were monitored in healthy crucian carps (Carassius auratus). 24 fishes were divided into three groups, and blood was collected before anaesthesia (control group), immediately after anaesthesia at a concentration of 30 mg/l clove oil (anesthetized group), and 24 h after anaesthesia (recovered group). The anesthesia to clove oil significantly increased glucose in anaesthetized group, and constantly decreased lactate dehydrogenase in anaesthetized group and recovered group.

To determine the effects of exposure to formalin on the secondary stress indices, changes in haematology and blood chemistry were monitored in healthy crucian carps (Carassius auratus). Fishes were separately exposed in a concentration range of 125 to 500 ppm formalin for 60 min. After exposure, red blood cell (RBC) count and packed cell volume (PCV) were elevated in the 500 ppm formalin exposed group. However, mean corpuscular volume (MCV) and mean corpuscular haemoglobin (MCH) were decreased significantly in the 500 ppm formalin exposed group.