Search results
Results from the WOW.Com Content Network
Cestodes are parasites of vertebrates, with each species infecting a single definitive host or group of closely related host species. All but amphilinids and gyrocotylids (which burrow through the gut or body wall to reach the coelom [ 6 ] ) are intestinal, though some life cycle stages rest in muscle or other tissues.
Adult trematodes lay smaller numbers of eggs compared to cestodes or nematodes. However, the egg develops into a miracidia from which thousands of cercariae , or swimming larvae, develop. This means that one egg may produce thousands of adult worms. [ 15 ]
Telorchis is a genus of trematode parasites found in many herps, comprising around 70 species. [2] This parasite is an indirect parasite, with a snail intermediate host and a reptile or amphibian definitive host.
Some internal fish parasites are spectacular, such as the philometrid nematode Philometra fasciati which is parasitic in the ovary of female Blacktip grouper; [14] the adult female parasite is a red worm which can reach up to 40 centimetres in length, for a diameter of only 1.6 millimetre; the males are tiny.
A fish parasite, the isopod Cymothoa exigua, replacing the tongue of a Lithognathus. Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. [1]
Schistosomes, unlike other trematodes, are long and cylindrical worms and are sexually dimorphic. The male S. mansoni is approximately 1 cm long (0.6–1.1 cm) [5] and is 0.1 cm wide. It is white, and it has a funnel-shaped oral sucker at its anterior end followed by a second pediculated ventral sucker.
Nematology research, like most fields of science, has its foundations in observations and the recording of these observations. The earliest written account of a nematode "sighting," as it were, may be found in the Pentateuch of the Old Testament in the Bible, in the Fourth Book of Moses called Numbers: "And the Lord sent fiery serpents among the people, and they bit the people; and much people ...
In 2014–15, the WHO estimated that approximately 2 billion people were infected with soil-transmitted helminthiases, [6] 249 million with schistosomiasis, [60] 56 million people with food-borne trematodiasis, [61] 120 million with lymphatic filariasis, [62] 37 million people with onchocerciasis, [63] and 1 million people with echinococcosis. [64]