UNASSIGNED: When hosts experience environmental stress, the quantity and quality of resources they provide for parasites may be diminished, and host longevity may be decreased. Under stress, parasites may adopt alternative strategies to avoid fitness reductions. @entity2439 parasites typically have complex life cycles, involving @entity249 in a gastropod first intermediate host. A rare phenomenon, briefly mentioned in the literature, and termed 'precocious encystment' involves the next stage in the parasites' life cycle (metacercarial cyst) forming within the preceding stage (redia), while still inside the @entity4245 . In the @entity2439 Parorchis sp. NZ using rocky shore snails exposed to long periods outside water, we hypothesised that this might be an adaptive strategy against desiccation, preventing parasite emergence from the @entity4245 . To test this, we first investigated the effect of prolonged desiccation on the survival of two species of high intertidal snails. Secondly, we measured the reproductive output (cercarial production) of the parasite under wet and dry conditions. Finally, we quantified the influence of desiccation stress on the occurrence of precocious encystment. @entity4245 mortality was higher under dry conditions, indicating stress, and it was somewhat exacerbated for infected snails. Parasite reproductive output differed between wet and dry conditions, with parasites of snails kept in dry conditions producing more cercariae when placed in water. Little variation was observed in the occurrence of precocious encystment, although some subtle patterns emerged. Given the stresses associated with living in high intertidal environments, we discuss precocious encystment as a possible stress response in this @entity2439 parasite.

Taken to the limit - Is desiccation stress causing precocious encystment of XXXX parasites in snails?

@entity249 :: ('MESH:D007246', 'Disease') :: ['asexual reproduction'] @entity2439 :: ('MESH:D014201', 'Disease') :: ['trematode', 'Trematode'] @entity4245 :: ('6615', 'Gene') :: ['Snail', 'snail']
@entity2439 :: (MESH:D014201,Disease) :: ['trematode']
