Influence of waterborne cadmium on the growth and immune-physiological parameters of Nile tilapia (Oreochromis niloticus)‎

Abstract EN

Nile tilapia, Oreochromis niloticus (65.2 ± 2.2 g) were randomly distributed into 12 glass aquaria to represent 4 treatments (3 replicates per treatment).

Fish were exposed to cadmium chloride at concentrations of 0.0 (control), 0.05 (T1), 0.10 (T2) and 0.15 mg L-1 (T3) for 4 weeks.

After the first, third and fourth week, fish were immediately anesthetized and blood was collected.

Fish weight was significantly affected by Cd exposure concentrations after the fourth week.

Survival rate was decreased significantly with increasing Cd concentrations at the end of the experiment.

The Cd accumulation was determined in fish gills, liver and muscles of Nile tilapia ; however, which these values increased significantly by increasing Cd concentrations and exposure period concentrations after the third and fourth week of exposure.

One week after exposure, IgM titer was significantly increased with increasing cadmium concentrations, while after the third and fourth week of exposure, IgM was significantly decreased with increasing Cd concentrations.

RBCs and Ht values were significantly decreased by increasing Cd concentrations where their highest values were obtained at control and the lowest ones were obtained at T3.

The lowest values of Hb were recorded at T1.

The MCV and MCHC values were insignificantly affected by Cd exposure, while MCH values were increased significantly with increasing Cd concentrations.

Serum total protein and globulin were not significantly affected by increasing Cd concentrations for the whole period, while albumin was significantly affected at T3 after the first and fourth week of exposure.

This study provides significant evidence that waterborne cadmium concentrations cause anemia and suppress immunity in exposed fish.

It could be concluded that Cd toxicity induced deleterious effects on fish, which were reflected on growth rate, residual of Cd in different tissues, the concentration of blood IgM and haematological parameters.

Moreover, immune.