Nutritional Factors affecting the Rate of Development of Fasciola hepatica in Limnaea truncatula

Abstract

This paper describes some hitherto unrecorded aspects of trematode development in a molluscan host.It is shown that the rate of development of Fasciola hepatica in its host Limnaea truncatula is influenced not only by temperature but by the amount of food assimilated by the snail and by the number of rediae which are in competition within a single host.The most rapid development of the parasite will occur in hosts which have access to ample supplies of food and in which moderate numbers of rediae become established. At laboratory temperatures, infection with a single miracidium rarely leads to the establishment of more than 40 rediae, a number which is apparently adjusted to the economy of the host, since it allows development at a maximum rate.