Search results
Results from the WOW.Com Content Network
These can be categorized into three groups; cestodes, nematodes and trematodes. Examples include: Acanthocephala; Ascariasis (roundworms) Cestoda (tapeworms) including: Taenia saginata (human beef tapeworm), Taenia solium (human pork tapeworm), Diphyllobothrium latum (fish tapeworm) and Echinococcosis (hydatid tapeworm)
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]
About 90% of nematodes reside in the top 15 cm (6") of soil. Nematodes do not decompose organic matter, but, instead, are parasitic and free-living organisms that feed on living material. Nematodes can effectively regulate bacterial population and community composition—they may eat up to 5,000 bacteria per minute.
Other internal parasites are found living inside fish gills, include encysted adult didymozoid trematodes, [15] a few trichosomoidid nematodes of the genus Huffmanela, including Huffmanela ossicola which lives within the gill bone, [16] and the encysted parasitic turbellarian Paravortex. [17]
There are 18,000 [1] to 24,000 [2] known species of trematodes, divided into two subclasses — the Aspidogastrea and the Digenea. Aspidogastrea is the smaller subclass, comprising 61 species. These flukes mainly infect bivalves and bony fishes. [3] Digenea — which comprise the majority of trematodes — are found in certain mollusks and ...
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]
Proteocephalidae is a diverse family tapeworms with nearly 300 recognized species in 66 genera and 13 subfamilies, whose species are found in every continent. They are mainly parasites of siluriforms and other freshwater fishes, but also parasitize reptiles and amphibians. [1]