Hematological parameters such as RBC count, Ht value, and Hb concentration can be a good indicator to assess the metal contamination in the aquatic environment as well as the status for the oxygen carrying ability (Shah and Altindag, 2004 and Seriani et al., 2015). In the present study, a considerable reduction in the RBC count, Ht value, and Hb concentration of rockfish was observed by the dietary lead exposure, which may be thought to result in reduced heme synthesis and anemia (Gurer et al., 1998).
The alterations of the parameters may be occur osmotic changes induced by metal toxicity resulting in hemo-dilution or hemoconcentration and red blood cell fragility, as well as impaired hematopoietic tissues (Shah, 2006). Gill and Epple (1993) suggested that anemia induced metal toxicity results from increased erythroclasis according to changed membrane permeability and elevated mechanical fragility, in addition to damage to erythropoiesis owing to a direct toxic influence of metal on hematopoietic tissues such as kidney and spleen.