Behavioral and biochemical consequences after chronic exposition to the herbicide atrazine in tadpoles.

Atrazine (ATZ) is the third most sold herbicide in Brazil, occupying the seventh position between most widely used pesticides. Due to its easy outflow, low reactivity and solubility, moderate adsorption to organic matter and clay, and long soil persistence, residual herbicide can be identified after long periods following application, and its usage has been prohibited in diverse countries. Amphibians are important bioindicators to assess impact of pesticide like atrazine, due to having a partial aquatic life cycle. This study had as objective to assess the response of bullfrog (Lithobates catesbeianus) tadpoles when exposed to this herbicide. Animals were exposed for a total of 168h to following concentrations: negative control, 40 µg/L, 200 µg/L, 2000 µg/L, 20000 µg/L of ATZ. Analysis of swimming activity was performed, and biochemical profile was assessed by analysis of blood and plasma glucose levels, urea, creatinine, cholesterol, HDL, triglycerides, glutamic pyruvic transaminase (GPT), alkaline phosphatase (AP), calcium, total proteins, phenol, peroxidase and polyphenol oxidase activity. Results exhibited malnutrition, anemia, likely muscle mass loss, and hepatic damage, indicating that ATZ can lead to an increase in energy to maintain homeostasis for animal survival.

Suplementaçäo com vitamina C e E sobre o desenvolvimento e sobrevivência de girinos de rä-touro (Rana catesbeiana Shaw, 1802) / Vitamin C and supplementation on the development and survival of bullfrog tadpoles (Rana catesbeiana Shaw, 1802)

O presente trabalho teve como objetivo avaliar os efeitos da suplementaçäo de vitamina C e E sobre o desenvolvimento e sobrevivência de girinos de rä-touro. Os animais receberam 50, 250 e 500mg de vitamina C ou E/kg de raçäo, distribuídos segundo delineamento inteiramente casualizado com 3 repetiçöes cada. Na dieta controle, näo foram adicionadas vitaminas. Os girinos suplementados com vitamina C ou E näo apresentaram diferença significativa no crescimento, comparadas ao controle. Näo obstante, os suplementados com 500mg de vitamina C apresentaram melhor sobrevivência (62,83 ppor cento) do que os animais controle (40,48 por cento; p<0,05), nos demais níveis desta vitamina e a adiçäo de vitamina E näo alteraram a sobrevivência. O presente trabalho sugere que 500mg de vitamina C/kg de raçäo constitui uma opçäo para melhorar a sobrevivência de girinos de rä-touro.