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Gastropod-borne parasitic diseases (GPDs) are a group of infectious diseases that require a gastropod species to serve as an intermediate host for a parasitic organism (typically a nematode or trematode) that can infect humans upon ingesting the parasite or coming into contact with contaminated water sources. [1]
A perspective on the evolutionary options can be gained by considering four questions: the effect on the reproductive fitness of a parasite's hosts; the number of hosts they have per life stage; whether the host is prevented from reproducing; and whether the effect depends on intensity (number of parasites per host). From this analysis ...
Just prior to host spawning, Polypodium everts to the normal position of cell layers, revealing tentacles scattered along the stolon. [2] During eversion, the yolk of the host oocyte fills the gastral cavities of the parasite, supplying the future free-living stage with nutrients. [2] [8] The parasitic phase of its life cycle usually takes ...
Some parasitic plants can locate their host plants by detecting chemicals in the air or soil given off by host shoots or roots, respectively. About 4,500 species of parasitic plant in approximately 20 families of flowering plants are known. [68] [70] Species within the Orobanchaceae (broomrapes) are among the most economically destructive of ...
Both fresh and ocean water fish can be parasitic vectors. Fish that act as second intermediate hosts are different species of the families Salmonidae, Cottidae, and Cyprinidae. Among the thirty-four natural and experimental secondary hosts found in scientific literature are the coastal cutthroat trout, rainbow trout, coho salmon, chum salmon ...
The Peronosporales too are mainly saprophytic or parasitic on plants, and have an aseptate, branching form. Many of the most damaging agricultural parasites belong to this order. The Lagenidiales are the most primitive; some are filamentous, others unicellular; they are generally parasitic. However more recently this has been expanded considerably.
The nauplii will go through three stages before molting into copepodids, which associate with fish gills. [2] After a further five stages and mating, the male leaves the host and dies, while the female transitions into the anchored stage (may move to different fish host). [2] An anchor worm Lernaea sp. parasite on a Murray cod
The evolutionary causes for the generation of nano and microstructured silica by photosynthetic algae are not yet clear. However, in 2018 it was shown that reflection of ultraviolet light by nanostructured silica protects the DNA in the algal cells, and this may be an evolutionary cause for the formation of the glass cages. [140] [141]