Toledo R, Muñoz-Antolí C, Pérez M, Esteban J G
Departamento de Parasitología, Facultad de Farmacia, Universidad de Valencia, Burjassot-Valencia, Spain.
Parasitol Res. 1999 Mar;85(3):212-5. doi: 10.1007/s004360050537.
A study was made of the infectivity of Hypoderaeum conoideum miracidia to a range of laboratory-reared specimens of freshwater snail species (Lymnaea peregra, L. corvus, Physella acuta, and Gyraulus chinensis) that coexist with the parasite in the same natural habitat. L. peregra and L. corvus were found to be equally susceptible to the parasite when specimens of each snail species were singly exposed to miracidia. However, when miracidia could choose either lymnaeid species, they showed a high degree of specificity toward L. peregra. The results obtained suggest that H. conoideum miracidia are capable of distinguishing among these lymnaeids in their orientation to the host. This indicates that miracidia might achieve specificity before actually contacting the snail host and suggests that during the host-snail orientation process they respond to signals different from those generated upon snail contact and invasion. The specificity toward L. peregra observed in H. conoideum miracidia seems to indicate adaptation to the snail community in their natural habitat, resulting in enhancement of their transmission.
对锥实螺毛蚴对一系列实验室饲养的淡水螺物种（静水椎实螺、乌鸦椎实螺、尖膀胱螺和中华圆扁螺）的感染性进行了研究，这些淡水螺物种与该寄生虫在同一自然栖息地共存。当分别将每种螺的样本单独暴露于毛蚴时，发现静水椎实螺和乌鸦椎实螺对该寄生虫同样敏感。然而，当毛蚴可以选择任一椎实螺物种时，它们对静水椎实螺表现出高度的特异性。所获得的结果表明，锥实螺毛蚴在朝向宿主的过程中能够区分这些椎实螺。这表明毛蚴可能在实际接触蜗牛宿主之前就实现了特异性，并表明在宿主 - 蜗牛朝向过程中，它们对与蜗牛接触和侵入时产生的信号不同的信号做出反应。锥实螺毛蚴对静水椎实螺观察到的特异性似乎表明其适应了自然栖息地中的蜗牛群落，从而提高了其传播能力。
