Le patelle delle coste campane: aspetti sistematici, cromosomici e valutazione delle stress genomico

Abstract

By applying advanced techniques that are available now days, it is relatively feasible to determine and monitor the degree of pollution of marine systems. However, it is still difficult to evaluate the effects that pollution may have on marine organisms and, in general, on the environment. A way to overcome this limit is by biomonitoring, i.e. by monitoring the biological responses of selected organisms (namely biomarkers) to pollutants. Many species of molluscs have been labelled as efficient biomarkers. In my research project the aim was to verify the appropriateness of limpets (Patella caerulea) as biomarkers by analyzing specimens of Patella collected in sites with different degrees of pollution along the coasts of the Campania region (Italy). To reach my goal, I measured the potential damage of pollutants at two levels: somatic (by monitoring gill histopathologies) and germinal (by monitoring gonad chromosomic aberrations). My results suggest that pollutants caused a significant damage in natural populations of P. caerulea. The gills of specimens collected from polluted sites presented structural changes, cell and tissue degeneration (cells with vacuoles, dissociation of haemocele septa, nuclear alterations), or the development of compensative mechanisms related to environmental toxicity (epithelium swelling, hyperplasia and fusion of septa). Furthermore, although preliminary, the results suggest that the level of gill injury appeared to be related to the degree of pollution of the study site. Finally, gill aberrations were always higher in each study site compared to the reference site. 2 The gonads of individuals of polluted sites also showed comparatively higher rates of chromosome aberrations, which are supposed to be a by product of an exposition to heavy metal and organic pollutants. In conclusion, the results obtained in my research project suggest that pollutants may act on the cells both of the somatic and germinal lineage in Patella and are thus potentially dangerous for the whole natural population of limpets of the Campania region