Integrative ecotoxicity evaluation of Cd, Cu, Zn and Ni in aquatic animals reveals high tolerance of Artemia franciscana

Abstract

Heavy metals pose a significant threat to animals in aquatic environments due to the adverse effects they exert. Species of the genus Artemia have been described as heavy metal tolerant, but the sensitivity/tolerance range for these species has not been established. In the present study, the toxicity of Cd, Cu, Zn and Ni as reported in the ECOTOX and Web of Science databases was examined for Artemia franciscana and compared with other species and taxonomic groups using an integrative ecotoxicity evaluation. The hazard concentration for 5% of the species (HC5) of acute toxicity tests (24–96 h), obtained through a species sensitivity distribution (SSD) indicated that Cu (0.02 mg/L) and Cd (0.03 mg/L) were the metals with the highest toxicity to aquatic animals followed by Zn (0.15 mg/L) and Ni (0.23 mg/L). In addition to the higher hazard of Cu and Cd to aquatic animals, the comparison of acute LC50 values for A. franciscana indicates lower toxicity of Cd followed by Cu, Zn, and Ni (200.0, 14.5, 9.5, and 0.6 mg/L, respectively). Using the SSD and physiological sensitivity (S) approaches, it was demonstrated that A. franciscana is relatively tolerant to Cd (SSD= HC99; S = 2.21), Cu (SSD= HC97; S = 2.00), Zn (SSD= HC90; S = 1.29) and Ni (SSD= HC83; S = 0.96) compared with other species and taxonomic groups. It appears that tolerance to the metals Cd, Cu, Zn and Ni is unique to the family Artemiidae within the order Anostraca, as the families Streptocephalidae and Thamnocephalidae are not tolerant (have negative S values). Our study confirmed that as expected, A. franciscana presents higher tolerance to Cd, Cu, Zn, and Ni than other aquatic animals. Our findings confirm that A. franciscana can be used as a model organism to understand mechanisms involved in tolerance to heavy metals, mainly Cd and Cu, which are considered highly toxic to other animals.