Acute Toxic Effects of Cadmium in Larvae of the Green Toad, Pseudepidalea Variabilis (Pallas, 1769) (Amphibia: Anura)

Abstract

The environmental impact of cadmium use and its accumulation in nature have increased to alarming levels. This study aimed to morphologically and histologically investigate the acute toxic effects of cadmium on green toad, Pseudepidalea variabilis (Pallas, 1769) larvae. Embryos were obtained from specimens collected in amplexus from nature and kept under laboratory conditions until stage 26, when they were exposed to cadmium (0, 1, 5, 10, 25, and 50 µg L -1 ) for 96 h. , respectively. Our results showed that cadmium had a negative effect on the body size of P. variabilis larvae (over 1 µg L -1 ). Histological examination detected a fusion of gill lamellae, liver haemorrhage, oedema in the abdominal cavity, and deformations of pronephric tubules (over 10 µg L -1 ). Our findings suggest that the green toad was sensitive to the cadmium treatment, with LC 50 values lower than those reported by other studies. Thus, this species could be considered a reliable indicator species of environmental stress in aquatic ecosystem.

Heavy metal mediated immunomodulation of the Indian green frog, Euphlyctis hexadactylus (Anura:Ranidae) in urban wetlands

“…Owing to the intimate association with the wetland ecosystem through diverse life-stages and other vulnerable traits, amphibians appear to be particularly sensitive to xenobiotics, including heavy metals (Hopkins et al, 2007;Gürkan et al, 2014;Franco-de-S and Val, 2014;Zhelev et al, 2013aZhelev et al, , 2014a. The exceptionally sensitive nature of amphibians qualifies them as sentinel species which warn mankind of serious biodiversity issues.…”

Effects of chronic cadmium exposure on metamorphosis, skeletal development, and thyroid endocrine disruption in Chinese toad Bufo gargarizans tadpoles

“…For example, more than 1 mg/L of Cd treatment would cause body size reduction in tadpoles of the green toad Pseudepidalea variabilis [11]. For example, more than 1 mg/L of Cd treatment would cause body size reduction in tadpoles of the green toad Pseudepidalea variabilis [11].…”

“…Because Cd is not biologically degradable [5][6][7], in some polluted areas Cd concentration is more than 100 mg/L-even reaching as high 200 mg/L-and this is much higher than the chronic criterion for Cd set by the US Environmental Protection Agency (USEPA; 0.15 mg/L) and the water quality standard set by the Ministry of Environmental Protection of China (0.01 mg/L) [2,[8][9][10]. Cadmium is considered to be highly toxic for all life forms, and it can cause adverse damages even in a very low dosage (1 mg/L) [11,12]. Therefore Cd pollution may pose great threats to aquatic life.…”

“…Many adverse effects of Cd on amphibians have been reported including developmental abnormality and delayed metamorphosis. For example, more than 1 mg/L of Cd treatment would cause body size reduction in tadpoles of the green toad Pseudepidalea variabilis [11]. Delayed metamorphosis and retarded swimming were detected in common Asian toad larvae exposed to Cd [13].…”

Prevalence and Concentration of Lead (Pb) and Cadmium (Cd) in Kales (<i>Brassica oleracea</i> Acephala) & Spinach (<i>Spinacia oleracea</i>) Sold at <i>Masaku</i> County, Kenya

“…These effects are believed to be irreversible. Lead exposure causes anemia, hypertension, renal impairment and toxicity to the reproductive system [7][8][9]. These outcomes are high in countries where children are exposed to lead poisoning due to gold mining [10].…”