Are fish and standardized FETAX assays protective enough for amphibians? A case study on Xenopus laevis larvae assay with biologically active substances present in livestock wastes.
Biologically active substances could reach the aquatic compartment when livestock wastes are considered for recycling. Recently, the standardized FETAX assay has been questioned, and some researchers have considered that the risk assessment performed on fish could not be protective enough to cover amphibians. In the present study a Xenopus laevis acute assay was developed in order to compare the sensitivity of larvae relative to fish or FETAX assays; veterinary medicines (ivermectin, oxytetracycline, tetracycline, sulfamethoxazole, and trimethoprim) and essential metals (zinc, copper, manganese, and selenium) that may be found in livestock wastes were used for the larvae exposure. Lethal (LC(50)) and sublethal effects were estimated. Available data in both, fish and FETAX studies, were in general more protective than values found out in the current study, but not in all cases. Moreover, the presence of nonlethal effects, caused by ivermectin, zinc, and copper, suggested that several physiological mechanisms could be affected. Thus, this kind of effects should be deeply investigated. The results obtained in the present study could expand the information about micropollutants from livestock wastes on amphibians.
Laboratory for Ecotoxicology, Department of Environment, Spanish National Institute for Agricultural and Food Research and Technology, INIA, Carretera de la Coruña, Km 7.5, 28040 Madrid, Spain.
Federica
F
Martini
José V
JV
Tarazona
M Victoria
MV
Pablos
D000818:Animals; D001681:Biological Assay / Q000379:methods* / Q000592:standards*; D003247:Conservation of Natural Resources / Q000379:methods*; D007814:Larva; D009152:Mutagenicity Tests / Q000379:methods* / Q000592:standards*; D012680:Sensitivity and Specificity; D013180:Sprains and Strains; D013723:Teratogens / Q000633:toxicity*; D014982:Xenopus laevis / Q000502:physiology*
D013723:Teratogens