Trace Metals Co-Toxicity in Hard Body Structures of Liza klunzingeri (Mugilidae: Perciformes) Mullet Fish

Abstract

The possibility of inorganic pollutants causing stress to the marine ecosystem instigated us to conduct eco-toxicological tests on the predominant trace metals (Cu, Zn, Pb and V) in commercial important fish. Among the four metals, V had the lowest observed effect concentration (LOEC: LC₁₅) at 6.3 µg L^-1. Toxicity tests (96 h) using Multi factor Probit analysis revealed V (6.3 µg L^-1) had the greatest effect at median lethal concentration (LC₅₀) followed by Pb (6.7 µg L^-1), Cu (7.8 µg L^-1) and Zn (15.7 µg L^-1) in Liza klunzingeri reared in filtered seawater in the laboratory. Fish exposed to trace metals mixture (1:1 ratio) showed synergistic co-toxicity coefficient (CTC) factor among Cu, Pb and Zn and antagonistic CTC with V mixtures. There was significant trace metals bioaccumulation in fish body structures (otolith, dorsal fins and scales) exposed for 180 day toxicity tests at LOEC. These results suggest there is value in ecologists to characterize L. klunzingeri as a bio indicator to metal pollution and enumerate the co-toxicity of trace metals in the marine environment.