Abstract：
Biomphalaria straminea is a freshwater gastropod native to South America and used in toxicological assessments. Our aim was to estimate 48 h-LC50 and sub-chronic effects after the exposure to low concentrations of chlorpyrifos as commercial formulation (CF) and active ingredient (AI) on B. straminea adult, embryos and juveniles. Concentrations between 1 and 5000 μg L-1 were chosen for acute exposures and 0.1 and 1 μg L-1 for the sub-chronic one. After 14 days biochemical parameters, viability and sub-populations of hemocytes, reproductive parameters, embryotoxicity and offspring\' survival were studied. Egg masses laid between day 12 and 14 were separated to continue the exposure and the embryos were examined daily. Offspring\' survival and morphological changes were registered for 14 days after hatching. 48 h-LC50, NOEC and LOEC were similar between CF and AI, however the CF caused more sub-lethal effects. CF but not the AI decreased carboxylesterases, catalase and the proportion of hyalinocytes with respect to the total hemocytes, and increased superoxide dismutase and the % of granulocytes with pseudopods. Also CF caused embryotoxicity probably due to the increase of embryos\' membrane permeability. Acetylcholinesterase, superoxide dismutase, hemocytes sub-populations, the time and rate of hatching and juveniles\' survival were the most sensitive biomarkers. We emphasize the importance of the assessment of a battery of biomarkers as a useful tool for toxicity studies including reproduction parameters and immunological responses. Also, we highlight the relevance of incorporating the evaluation of formulations in order to not underestimate the effects of pesticides on the environment.
摘要：
Biomphalariastraminea是原产于南美的淡水腹足纲动物，用于毒理学评估。我们的目的是估计暴露于低浓度毒死蜱作为商业制剂（CF）和活性成分（AI）后的48h-LC50和亚慢性效应。胚胎和青少年。急性暴露的浓度为1至5000μgL-1，亚慢性暴露的浓度为0.1和1μgL-1。14天后生化指标，存活力和血细胞亚群，生殖参数,研究了胚胎毒性和后代存活。将在第12天和第14天之间产下的卵块分离以继续暴露,并且每天检查胚胎。孵化后14天记录后代的存活和形态变化。CF和AI之间48h-LC50，NOEC和LOEC相似，然而CF引起更多的亚致死效应。CF而不是AI降低羧酸酯酶，过氧化氢酶和透明质酸细胞占总血细胞的比例，并增加了超氧化物歧化酶和伪足类粒细胞的百分比。CF也引起胚胎毒性，可能是由于胚胎膜通透性的增加。乙酰胆碱酯酶,超氧化物歧化酶,血细胞亚群，孵化的时间和速率以及幼体的存活率是最敏感的生物标志物。我们强调评估一系列生物标志物作为毒性研究（包括生殖参数和免疫反应）的有用工具的重要性。此外，我们强调纳入制剂评估的相关性，以免低估农药对环境的影响。
