Parasites/parasitism vertebrate

Fig. 1.5. Phylogeny of the deuterostomes indicating position of oldest fossil taxa against the geological record. All neodermatans parasitize vertebrates and, if present, host associations represent historical associations the Neodermata must have parasitized the stem group Gnathostomata between the Cambrian and Ordovician. Tree redrawn from Rowe (2004).

Whatever the functional advantages conferred by the neodermis might be, clearly these need to be elucidated further. The obligate parasitic flatworms share another important characteristic feature - with the exception of a few derived forms, they almost all parasitize vertebrates and use them as a host where they reach maturity, reproduce and complete their life cycle. Monogeneans are found predominantly on their respective hosts and the Trematoda and Cestoda are found predominantly in their hosts. 

Si ova-Kasatockina, O. A. Dubovskaja, A. J. (1975). Proteinase activity in certain cestode species parasitizing vertebrates of different classes. Acta Parasitologica Polonica, 23 389-93. 

The immune system in vertebrates provides a defense mechanism against foreign parasites such as viruses and bacteria. Three main properties are essential to its successful operation specific recognition of foreign molecules, the ability to destroy the foreign parasite, and a memory mechanism that allows a more rapid response to a second infection by the same microorganism. 

IFNs are natural glycoproteins produced by the cells of most vertebrates in response to the challenge by foreign agents, such as infectious organisms (viruses, bacteria, fungi, and parasites), and by tumor cells. IFNs can be produced by cells of the innate and adaptive immune systems and by non-immune cells such as fibroblasts and epithelial cells. 

The cyclodiene insecticides aldrin, dieldrin, endrin, heptachlor, endosulfan, and others were introduced in the early 1950s. They were used to control a variety of pests, parasites, and, in developing countries, certain vectors of disease such as the tsetse fly. However, some of them (e.g., dieldrin) combined high toxicity to vertebrates with marked persistence and were soon found to have serious side effects in the field, notably in Western European countries where they were extensively used. During the 1960s, severe restrictions were placed on cyclodienes so that few uses remained by the 1980s. 

Fungivore Phytoparasite U Entomopathogen Invertebrate parasite tf Vertebrate parasite... 

Within the Nematoda, parasitism has arisen multiple times (Blaxter et al., 1998). The plant-parasitic Tylenchida, Dorylaimida and Triplonchida have acquired the phenotype independently. The insect/invertebrate parasitism of the species in clades V, IV, III and I have similarly arisen independently. Vertebrate parasitism has arisen at least four times, in the Trichocephalida of clade I, the three orders in clade III, the Strongyloidi-dae of clade IV and the Strongylida of clade V. As there are still additional animal parasitic groups that have not been analysed (importantly including Dioctophyme and Capillaria) the number of independent acquisitions of vertebrate parasitism predicted may still be an underestimate. The import... 

Anderson, R.C. (1992) Nematode Parasites of Vertebrates. Their Development and Transmission. CAB International, Wallingford, UK. 

Cholinesterases secreted by parasitic nematodes of (predominantly) the alimentary tract or other mucosal tissues are authentic AChEs when analysed by substrate specificity, inhibitor sensitivities and primary structure. In the first two respects, they resemble vertebrate AChEs, whereas somatic (and therefore presumably neuronal) enzymes of nematodes analysed to... 

Both male and female tsetse live solely on vertebrate blood, and the various species that carry sleeping sickness typically feed not only on humans but also on both domestic and wild animals. Infected flies pass on trypanosomes whenever they take a blood meal, so that the parasites not only move between flies and humans, but also infect a number of other hosts. Infected domestic animals develop nagana, but wild animals may show no sign of illness. They serve instead as healthy animal reservoirs of trypanosomes, permitting tsetse flies to pick up the parasites at any time without necessarily feeding on infected humans or domestic animals. For this reason and also because available drug therapies have proved no more practical here than for leishmaniasis, control of trypanosomiasis has long emphasized eradication of tsetse flies. 

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