Paratenic

In parasitology, the term paratenic describes an intermediate host which is not needed for the development of the parasite, but nonetheless serves to maintain the life cycle of the parasite. Alaria americana may serve as an example: the so-called mesocercarial stages of this parasite reside in tadpoles, which are rarely eaten by the definite canine host. These are more frequently preyed on by snakes, in which the mesocercariae may not undergo further development. However, the parasites may accumulate in the snake paratenic host and infect the definite host once the snake is consumed by a canid.