The effects of sublethal concentrations of cadmium on haematological parameters in the dogfish, Scyliorhinus canicula

Dogfish were subjected to sublethal cadmium exposure (25 mg l⁻¹) for 24 and 96 h. The effects of this treatment on some blood parameters were analysed. Decreases of haematocrit, leucocrit and mean corpuscular volume and increases of haemoglobin concentration, red blood cell count and mean corpuscular haemoglobin concentration were observed after 24-h exposure. Most parameters which had changed values at 24 h returned to control values at 96 h, whereas some parameters which were unchanged at 24 h showed a significant variation at 96 h (plasma glucose and lactate levels). The causes of these alterations and the patterns of recovery are discussed.