Biological responses in edible crab, Callinectes amnicola that could serve as markers of heavy metals pollution
Responses of lagoon crab, Callinectes amnicola were explored as useful biological markers of heavy metal pollution. The toxicity level of the metals based on the 96-h LC50 values showed that copper with LC50 value of 0.018 mM was found to be two times more toxic than Lead (0.041 mM) against the lagoon crab, C. amnicola. The exposure of the lagoon crab to sublethal concentrations (1/100th and 1/10th of 96-h LC50 values) of Cu and Pb compound, respectively, resulted in the bioaccumulation of the test metals to varying degrees in the selected organs that were dependent on the type of metal and concentration of metal compound in the test media. The degree of metal (Cu and Pb) accumulation was generally in the following order: gills > muscle > heptopancrease. Exposure of the crabs to sublethal concentrations of the metals also caused pathological changes such as the disruption of the gill filaments and degeneration of glandular cells with multifocal areas of calcification in the hepatopancreas. A reduction in the weight of the exposed animals over a 14-day period of observation was also recorded. The significance of these results and the usefulness of the biological endpoints in monitoring programmes aimed at establishing the total environmental level of heavy metals in aquatic ecosystems were discussed.
KeywordsHeavy metals Biomarkers Histopathology Bioaccumulation Biomonitoring
The authors are grateful to Dr. J.K. Saliu for his useful suggestions in the preparation of the manuscript.
- Baron MG (1995) Bioaccumulation and bioconcentration in aquatic organisms. In: Hoffman GA, Rattner BA Jr, Ciaras GA Jr (eds) Handbook of ecotoxicology. CRC press Inc. Lewis Publishers, London, pp 652–662Google Scholar
- Chukwu LO (1991) Studies on heavy metal contamination of water sediments and decapod crustaceans from River sasa. PhD Thesis, University of Lagos, 164 ppGoogle Scholar
- Clark RB (1992) Marine pollution, 3rd edn. Oxford University Press, Oxford, p 169Google Scholar
- FAO/SIDA (1986) Manual of methods in aquatic environmental research, Part 9. Analyses of metal and organochlorines in fish. FAO Fish Tech Pap 212:21–33Google Scholar
- Finney DJ (1971) Probit analysis, 3rd edn. Cambridge University Press, LondonGoogle Scholar
- Harada M, Smith AM (1975) Minamata disease: a medical report. In: Smith WE, Smith AM (eds) Minamata: a warning to the world. Chatto and Windus, London, pp 180–192Google Scholar
- Kurdland L (1960) Minamata disease. World Neurol 1:370–385Google Scholar
- Otitoloju AA, Don-Pedro KN (2002) Bioaccumulation of heavy metals (Zn, Pb, Cu and Cd) by Tympanotonous fuscatus var radula (L) exposed to sublethal concentrations in laboratory bioassays. W Afr J Appl Ecol 3:17–29Google Scholar
- Otitoloju AA, Don-Pedro KN (2006) Influence of joint application of heavy metals on level of each metal accumulated in the periwinkle Tympanotonus fuscatus Gastropoda: Potamididae. Int J Trop Biol 54(3):803–814Google Scholar
- Oyewo EO (1998) Industrial sources and distribution of heavy metals in Lagos lagoon and their biological effects on estuarine animals, PhD Thesis, University of Lagos, 274 ppGoogle Scholar
- Radhakrishnaiah K (1988) Accumulation of copper in the organs of freshwater fish, Labeo rohita (Hamilton), on esposure to lethal and sublethal concentration of copper. J Environ Biol 9(3)(Suppl):319–326Google Scholar
- World Health Organisation (1995) Human exposure to lead, World Health Organization GenevaGoogle Scholar