Evaluation of Possibillity of Stock Discrimination of a Species of Caspian Sea Bony Fishes (Rutilus kutum) Through Elemental Fingerprinting of Hard Tissues of The Body

Abstract

The information about differences in the chemical composition of skeletal structures (e.g. otoliths) have proven useful for reconstructing the environmental history of many marine species.in this reaserch, concentration levels of 12 trace elements (Zn, Fe, Sr, Cl, Mn, Mg, Na, P,Ca, K, Br and S) were measured in the skeletal structures containsotolith, scale , eye lenses, vertebra and fin ray of a species of Caspain sea bony fishes (Rutilus frisii kutum) collected from the three diffrent sites of southern areas of Caspain sea (gilan, mazandaran and golestanprovinces). Samples analysed by particle-induced X-ray emission (PIXE) technique to determine the concentrations of studied trace elements. The results showed that the concentration of Ca in different organs of samples except eye lenses in three different sites were more than other metals (p<0.05). How ever calcium concentration in eye lenses was not only dominate but also was in very small amounts. With regards to the Sr level in otolith, no significant differences could be found between the sampling sites 2 and 3. So it can be concluded that the specimens collected from the two sites are probably from the same population. Similar results were also obtained based on the results concerning K accumulation in scale. It can be concluded that scales may provide an alternative structure to otolith for stock discrimination of R. kutum in the southern Caspian Sea.