Seasonal variation in the toxicity of umbelliferone against Fasciola larvae.

Snail is one of the important components of aquatic ecosystem it act as intermediate host of Fasciola species. The life cycle of parasite can be interrupted by killing the vector snail or Fasciola larva (sporocyst, redia and cercaria) inside the snail body. Effect of abiotic factors on the toxicity of umbelliferone against Fasciola larvae in different months of the year 201 1 -201 2. In highest in vivo toxicity is noted of umbelliferone against, redia and cercaria larva was noted in month of May and July (redia - 8h LC50=0.93, and 0.89 mg/L; cercaria - 8h LC50=0.70 and 0.92 mg/L). In in vitro treatment highest toxicity against redia and cercaria larva was absorbed June, July and August (redia - 8h LC50= 0.26, 0.30 and 0.28 mg/L; cercaria - 8h LC50=0.09, 0.1 1 and 0.1 8 mg/L). The lowest toxicity was observed the month of November to January. The highest temperature, free carbon dioxide, and lowest pH, dissolved oxygen were observed in the months of June to August. The present study conclusively shows that variant abiotic factor can significantly alter the in vitro and in vivo toxicity of umbelliferone against sporocyst redia and cercaria larva. [ABSTRACT FROM AUTHOR]