trematodes are important in economic and public health. ornithobilharzia turkestanicum (o. turkestanicum) is one of the important economic trematodes in domestic animals. ornithobilharzia infection in intermediate host (lymnaea gedrosiana ) can be detected by either exposing snails to light to induce cercarial shedding or by squeezing them between glass slides to detect parasites. the current a...

background: trematodes belonging to the genus schistosoma cause schistosomiasis. the relationship between schistosomes and their intermediate hosts varies among snails. this study investigated the effects of s. japonicum on its snail host, oncomelania hupensis, and cercarial release rythmicity of s. japonicum and the effects of light on it. methods: : seven groups of o. hupensis (n = 40 each) w...

Nonhost resistance is often conceptualized as a qualitative separation from host resistance. Classification into these two states is generally facile, as they fail to fully describe the range of states that exist in the transition from host to nonhost. This poses a problem when studying pathosystems that cannot be classified as either host or nonhost due to their intermediate status relative to...

The fundamental assumption underpinning the evolution of numerous adaptations shown by parasites with complex life cycles is that huge losses are incurred by infective stages during certain transmission steps. However, the magnitude of transmission losses or changes in the standing crop of parasites passing from upstream (source) to downstream (target) hosts have never been quantified in nature...

Larval helminths of different species that share the same intermediate host and are transmitted by predation to the same definitive host may cooperate in their attempts to manipulate the behaviour of the intermediate host, while at the same time having conflicts of interests over the use of host resources. A few studies have indicated that intermediate hosts harbouring larval helminths have alt...

Larval helminths often share individual intermediate hosts with other larval worms of the same or different species. In the case of immature acanthocephalans capable of altering the phenotype of their intermediate hosts, the benefits or costs of host sharing can be evaluated in terms of increased or decreased probability of transmission to a suitable definitive host. Competitive interactions am...