title: Cadmium pollution and amphibians--Studies in tadpoles of Rana limnocharis.
abstract: Cadmium is released into the environment in increasing amounts from different natural and anthropogenic activities contaminating the aquatic habitats. Amphibian tadpoles develop in water and hence are likely to be adversely affected by cadmium present in the aquatic environment. We have studied the toxic and genotoxic effects of CdCl2 on the tadpoles of Rana limnocharis. CdCl2 in the concentration range between 0.1 and 0.4 mg/L induced significant mortality in R. limnocharis tadpoles in a dose and time dependent manner. The 10-day LC50 which has more ecological relevance was far less than the 24-h LC50. Tadpoles exposed to CdCl2 metamorphosed at an early age possibly as a survival strategy to move out of the stressful environment. The body weight of the CdCl2 exposed animals at metamorphosis was lower compared to the control individuals which may affect survival and reproductive fitness in adult life. Besides, the average body length of the metamorphosed individuals in the CdCl2 exposed group was higher than the control group. CdCl2 was found to be genotoxic in micronucleus test and comet assay. The ambient concentration of Cd could reach up to 60 μg/L or more. Exposure to 18.5 μg/L of CdCl2 (1% of 24-h LC50) induced significant increase in DNA strand breaks as compared to the control. The present findings demonstrate that presence of cadmium in the aquatic environment can significantly alter the life history traits and cause DNA damage in amphibians and hence, could contribute towards their population decline.
authors.affiliation: Environmental Toxicology Laboratory, Department of Life Science and Bioinformatics, Assam University, Silchar 788 011, India.
authors.forename: Arabinda
authors.initials: A
authors.lastname: Patar
authors.affiliation: Environmental Toxicology Laboratory, Department of Life Science and Bioinformatics, Assam University, Silchar 788 011, India. Electronic address: agiri123@yahoo.com.
authors.forename: Anirudha
authors.initials: A
authors.lastname: Giri
authors.affiliation: Environmental Toxicology Laboratory, Department of Life Science and Bioinformatics, Assam University, Silchar 788 011, India.
authors.forename: Freeman
authors.initials: F
authors.lastname: Boro
authors.affiliation: Environmental Toxicology Laboratory, Department of Life Science and Bioinformatics, Assam University, Silchar 788 011, India.
authors.forename: Krishna
authors.initials: K
authors.lastname: Bhuyan
authors.affiliation: Environmental Toxicology Laboratory, Department of Life Science and Bioinformatics, Assam University, Silchar 788 011, India.
authors.forename: Utsab
authors.initials: U
authors.lastname: Singha
authors.affiliation: Molecular Cytogenetics Laboratory, Department of Life Science and Bioinformatics, Assam University, Silchar 788 011, India.
authors.forename: Sarbani
authors.initials: S
authors.lastname: Giri
mesh_terms: D000818:Animals; D001001:Anura / Q000235:genetics / Q000254:growth & development; D002104:Cadmium / Q000633:toxicity*; D019256:Cadmium Chloride / Q000633:toxicity; D020552:Comet Assay; D004249:DNA Damage; D004305:Dose-Response Relationship, Drug; D007814:Larva / Q000187:drug effects; D008018:Life Cycle Stages / Q000187:drug effects; D008675:Metamorphosis, Biological / Q000187:drug effects; D015162:Micronucleus Tests; D009153:Mutagens / Q000633:toxicity; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D009153:Mutagens; D014874:Water Pollutants, Chemical; D002104:Cadmium; D019256:Cadmium Chloride
keywords: Cadmium; Comet assay; Genotoxicity; Metamorphosis; Micronucleus; Rana limnocharis