Trace elements in fish species: Schizothorax richardsonii, Salmo trutta and Neolissochilus hexagonolepis in relation to sizes and tissues of Punatsang Chhu

Abstract

Three fish species ( Schizothorax richardsonii, Salmo trutta and Neolissochilus hexagonolepis ) were collected from Punatsang Chhu river and sample tissues of muscles and gills were analyzed for Al, As, Ba, Cd, Co, Cr, Cu, Fe, K, Mn, Mo, Ni, Pb, Se, Sr and Zn using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). Principal Component Analysis (PCA) for each species grouped elements with higher concentration in gills compared to muscle tissues. The Man-Whitney test revealed significant difference between tissues sources and concentrations of Al, Ba, Cd, Co, Fe, K, Mn, Mo, Ni, Sr and Zn in S. richardsonii , Al, Ba, Co, Fe, K, Mn, Ni, Sr and Zn in S. trutta and Al, Ba, Co, Cr, Fe, K, Mn, Sr and Zn in N. hexagonolepis. The Kruskal-Wallis test for inter-species variation revealed significant difference in concentration of As, Cr, Cu, Fe, Mn, Ni and Zn in muscle tissues and Ba, Cr, Cu, Mn, Sr and Zn concentrations in gills of three species. Spearman correlation between levels of elements and fish size (weight and length) revealed positive and negative relationships for concentrations of As, Ba, Cd, Co, Cr, Cu, Fe, K, Mn, Ni, Pb, Sr, and Zn and concentrations of Al, Ba, Cd, Co, Fe, K, Mn, Mo, Ni, Sr and Zn respectively, both at p < 0.001 and p < 0.005. • Sixteen trace elements analyzed in tissues of the three fish species using ICP-OES. • Significant differences in concentration of trace elements in gills and muscle tissues of three fish species. • Strong to moderate of both positive and negative correlations between fish sizes and concentration of trace elements. • Interspecies concentration significantly different for most of the trace elements. • MPI observed highest in Schizothorax richardsonii for both gills and muscle tissues compared to other two species.