en عمومى General پژوهشي Research <p><strong>Background:</strong> There has been increasing awareness throughout the world regarding the remarkable decrease in amphibian population. For such amphibian population decline several causes have been given. Cadmium, a heavy metal is released both from natural sources (leaching of cadmium rich soils) and anthropogenic activities to the aquatic and terrestrial environments. This study evaluated the toxicity of heavy metal cadmium to Indian skipper frog <em>Rana cyanophlyctis</em>.</p> <p><strong>Methods:</strong> For the determination of LC₅₀ values for cadmium, four-day static renewal acute toxicity test was used. Five replicates each containing ten frogs were subjected to each concentration of cadmium chloride (15, 20, 25, 30, 35, 40, 45 and 50 mg/L). At different exposure periods (24, 48, 72 and 96 h), the mortality of the frog was subjected to Probit analysis with the POLO-PC software (LeOra Software) to calculate the LC₅₀ and 95% confidence level.</p> <p><strong>Results:</strong> The LC₅₀ values of cadmium chloride for the frog<em> R. cyanophlyctis</em> at 24, 48, 72, and 96 h are 32.586, 29.994, 27.219 and 23.048 mg/L, respectively. The results have been discussed with the toxicity reported for other aquatic vertebrate --fish.</p> <p><strong>Conclusion:</strong> Cadmium caused mortality to the frog and this could be one of the reasons for population decline of frogs which inhabit water contaminated with heavy metals.</p> Amphibia, Cadmium, Heavy Metal, LC50, Toxicity. 39 43 http://ijt.arakmu.ac.ir/browse.php?a_code=A-10-74-3&slc_lang=en&sid=1 Ajai Kumar Srivastav ajaiksrivastav@hotmail.com 10031947532846005521 10031947532846005521 Yes Department of Zoology, DDU Gorakhpur University, Gorakhpur 273 009, India. Shilpi Srivastav 10031947532846005522 10031947532846005522 No Department of Zoology, DDU Gorakhpur University, Gorakhpur 273 009, India. Nobuo Suzuki 10031947532846005523 10031947532846005523 No Kanazawa University, Ogi, Noto-cho, Ishikawa 927-0553, Japan