Evaluation of copper effects upon Girardia tigrina freshwater planarians based on a set of biomarkers.
Copper is a common environmental contaminant, which is particularly toxic to living organisms when in high concentrations. To monitor environmental contamination by Cu2+ and other heavy metals, well characterized bioindicator organisms and standardized assays are needed. As a first step toward this end, we have analysed Cu2+ effects upon Girardia tigrina freshwater planarians, based on the assessment of mobility, regeneration performance, micronucleus (MN) frequency in regenerating animals, and reproductive performance. These four biomarkers provided complementary information on Cu2+ toxicity, teratogenicity, mutagenicity and chronic (>96 h of exposure) effects, respectively. The LC50 was calculated for newborn, adult and regenerating planarians, and values of 12+/-0.02 mg l(-1), 42+/-0.08 mg l(-1), 48+/-0.13 mg l(-1), respectively, were obtained after 96 h of exposure. Mobility, for intact adults, and time of regeneration and MN frequency, for regenerating animals, were significantly affected by Cu2+ concentrations as low as 0.10 mg l(-1). MN assay for regenerating G. tigrina neoblasts showed higher sensitivities than MN assays performed with other bioindicator freshwater organisms, such as moluscs or fish. Chronic exposure effects were clearly evidenced by assessment of reproductive performance, with significant reduction in fecundity and fertility rates upon exposure to Cu2+ concentrations as low as 0.05 mg l(-1). Therefore, G. tigrina can be regarded as a useful bioindicator species for the detection and evaluation of Cu2+ effects upon freshwater invertebrates, allowing insights on the effects of Cu2+ (and possibly other heavy metals) in a freshwater environment.
Knakievicz
Tanise
T
Laboratório de Biologia Molecular de Cestódeos, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, 9500 - Prédio 43421, salas 204 e 206 Caixa Postal 15005 CEP: 91501-970 Porto Alegre, RS, Brazil.
Ferreira
Henrique Bunselmeyer
HB
D000818:Animals; D015415:Biomarkers; D003300:Copper / Q000633:toxicity*; D007928:Lethal Dose 50; D008124:Locomotion / Q000187:drug effects; D015162:Micronucleus Tests; D010932:Planarians / Q000187:drug effects* / Q000502:physiology; D012038:Regeneration / Q000187:drug effects; D012098:Reproduction / Q000187:drug effects; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D015415:Biomarkers; D014874:Water Pollutants, Chemical; D003300:Copper