Assessment of the Ameliorative Roles of Vitamins A, C and E on Morphometric Parameters of Clarias Gariepinus (Burchell, 1822) Fingerlings Exposed to Cadmium Choride.

Abstract

Environmental pollution in the form of Cd is a major environmental problem arising mostly from anthropogenic activities all over the world causing both health and economic loses either in the short- or long-run. The roles of vitamins in mitigating the effects of Cd toxicant in term of morphological differentiation were investigated. Clarias gariepinus fingerlings (whose initial weight ranged from 3-11g, standard length ranged from 7.9-9.4cm and total length ranged from 8.9-10.9cm) were exposed to sub-lethal concentrations of Cd (00, 12mg/L, 16mg/L, 20mg/L and 24mg/L) with replicate in each case. Minimum concentration of the toxicant was taken as the concentration for each of the vitamins and administered to all treatments. The morphometric parameters measured on weekly basis for a period of 12 weeks were standard lengths (SL), total lengths (TL) and weight from 2 randomly selected samples from each treatment and replicate. Fresh concentrations of the toxicant and vitamins were prepared and administered every 72 hours following standard procedures when the water was changed. The various treatments group include Cd (Cd only with T1-T4 and replicates), CdVA (Cd+vitamin A with T1-T4 and replicates), CdVC ((Cd+vitamin C with T1-T4 and replicates) and CdVE (Cd+vitamin E with T1-T4 and replicates). The weight derivatives such as specific growth rate (SGR), weight gain (WG) and % weight gain (% WG) were also calculated at the end of the exposure periods. Length-weight regression analysis as well as one way ANOVA was used to establish relationships. From the results: The highest SL in Cd only treatments was recorded in T1 at the 5th week with 10.50cm. The samples exposed to CdVA exhibited slow growth through-out the exposure period. The highest SL in CdVC treatments was recorded at week 8 in T1 with 10.60cm. There were sight general improvements in growth in this case. The maximum SL in CdVE were obtained in T2 with 10.70cm at the 7th and 8th week of exposure. The highest TL in samples exposed to Cd treatments was recorded at the 5th week in T2 with 11.80cm.There was general poor performance in the total TL when compared with the control samples. In CdVA the highest was also recorded in T1 with 10.90cm at the 1st week after exposure.The maximum TL in samples subjected to CdVC was 12.30cm in T1 at the 1st week. CdVE treatments recorded 12.40cm as the highest in T2 at the 7th week. Samples exposed to Cd treatments had the highest weight of 13.81g in T1 at the 5th week of exposure. There was also general decline in weight especially at the later stages. The highest weight obtained in samples exposed to CdVA treatments was 9.54g in T2 at the 3rd week of exposure. The samples exposed to CdVC treatments indicated that the highest weight was recorded in T3 at the 7th week with 13.13g. The maximum weight obtained in samples exposed to CdVE treatments was 15.43g in T2 at the 7th week of exposure; negative %WG and low values of SGR were also recorded. The relationships between length and weight of C. gariepinus were linear throughout the period of exposure in all Cd treatment groups. T2 samples in all Cd treatment groups had the highest R2 values (0.6796) with the exception of CdVE treatments. The outcome of this research suggests that CdCl2 is very deleterious and higher concentrations of the vitamins may be required in attenuating the effects of the toxicant given that there were sight improvements in treatments with vitamins.