Concentrations of trace metals in squid, Loligo duvaceli and Doryteuthes sibogae caught from the south west coast of India

Abstract

Concentrations of trace metals like Hg, Cd, Pb, Cu, Zn, Fe, Mn, Cr, Co, and Ni were determined in the squids, Loligo duvauceli and Doryteuthis sibogae collected from Mangalore, Cochin and Quilon, the three major fish landing centers in the west coast of India, from August 1998 to December 1999. The mean values (highest at the three stations) of highly hazardous metals in the muscle of the two species, were: Hg < 0.05, 0.07; Cd = 0.55, 0.89; Pb = 0.99, 0.89; Cr = 0.72, < 0.45 and Ni = 0.45, 0.19 ppm, all within the international safety limits. However, elevated levels of some of the metals, particularly Cd, Zn and Cu were sometimes observed. The liver, the major site of metal accumulation, is probably as complex as metallothioneins. Gills and ink also significantly concentrate metals. Cadmium levels in the muscle increased with growth in L. duvauceli and liver concentrations of Cd, Cu, Zn significantly correlated with total length. Geographical variations in metal levels were observed in these species.