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| − | {{unfinished}} | + | {{frontpage |
| − | | + | |pagetitle =Nematodes |
| − | == Introduction == | + | |pagebody = <div style="text-align: left; direction: ltr; margin-left: 1em;"> |
| − | [[Image:Soybean cyst nematode EM.jpg|thumb|right|150px|Soybean Cyst Nematode and Egg, Scanning Electron Micrograph - Wikimedia Commons]]
| + | Nematodes are one of the most prolific life-forms on this planet. Most are free-living, with species adapted to every imaginable habitat. Some are parasitic on plants, and others on animals. The animal parasitic nematodes form a large and diverse array of organisms. Occlusion of [[Pancreas - Parasitic Pathology|pancreatic ducts]] sometimes happens. |
| − | [[Image:Mononchidae eating a Mononchidae.jpg|thumb|right|150px|Mononchidae eating a Mononchidae - Wikimedia Commons]]
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| − | Nematodes are one of the most prolific life-forms on this planet. Most are free-living, with species adapted to every imaginable habitat. Some are parasitic on plants, and others on animals. The animal parasitic nematodes form a large and diverse array of organisms. | |
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| − | == The Nematodes ==
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| − | === Recognition Features ===
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| − | *A unique feature of the nematodes is that the fluid in the body cavity is maintained under high pressure (this is why nematodes often burst after collection)
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| − | *They therefore have a tough elastic cuticle which often forms elaborate structures useful for identification
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| − | *A muscular pharynx is needed to pump food into the intestine
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| − | *The shape of the pharynx is characteristic in some groups
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| − | *There is a nerve ring around the pharynx and four longitudinal nerves with ganglia that co-ordinate movement (many anthelmintics act by disrupting neuromuscular co-ordination)
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| − | *The sexes are separate:
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| − | **the female tail generally ends in a blunt point
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| − | **males usually have two chitinous rods that can be protruded through the cloaca to hold the female - these are called spicules and, being chitinous, are easily seen under the microscope. As these differ in shape and size between species, they are very useful in identification
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| − | *The '''bursate nematodes''' are characterised by a large expansion of the cuticle of the male tail to form a clasping organ (the bursa)
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| − | *Other modifications of the cuticle on both male and female nematodes useful for identification include:
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| − | **'''alae''' (wing-like protrusions)
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| − | **'''vesicles''' (swellings around the whole circumference of the body)
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| − | *The heads of some nematodes have structures such as:
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| − | **leaf-like lips around the mouth (the '''leaf-crown''')
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| − | **a '''buccal cavity'''
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| − | **'''teeth''' or '''cutting plates'''
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| − | === Feeding Habits ===
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| − | *Many intestinal nematodes are closely applied to the mucosal surface
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| − | *Some swallow ingesta and/or host secretions.
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| − | *Others suck a plug of mucosa into the buccal cavity (plug feeders), leaving a circular ulcer
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| − | *Yet others bury their heads deep into the mucosa and suck blood
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| − | | |
| − | === General Life-Cycle ===
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| − | *The basic life-cycle is very simple:
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| − | **egg → L1 → L2 → L3 → L4 → adult
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| − | *With a moult in between each larval stage
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| − | *But there are many variations on this theme
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| − | === Nematode Eggs ===
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| − | *These vary greatly in appearance and are very useful for diagnosis as they can often be detected and counted in faecal samples
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| − | *NOTE: we use the typical '''strongyle''' egg to provide us with a yard-stick for comparing sizes. A "large egg", for example, means larger than a strongyle egg. A typical strongyle egg is approximately '''80µm''' long
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| − | == Nematode Superfamilies ==
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| − | <ncl style=compact maxdepth=5 headings=bullet headstart=2 showcats=1 showarts=1>Category:{{PAGENAME}}</ncl>
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| | From the veterinary view-point, the nematodes are most conveniently grouped into '''superfamilies''' because their members often have similar life-cycles and epidemiological features. Superfamily names end in -oidea (the anglicised form is -oid, as in trichostrongyloid). | | From the veterinary view-point, the nematodes are most conveniently grouped into '''superfamilies''' because their members often have similar life-cycles and epidemiological features. Superfamily names end in -oidea (the anglicised form is -oid, as in trichostrongyloid). |
| − | | + | </div> |
| − | == Nematodes of Different Species == | + | |contenttitle =Content |
| − | | + | |contentbody =<big><b> |
| − | [[:Category:Cattle Nematodes|Cattle Nematodes]]
| + | <br> |
| − | | + | <categorytree mode="pages">Nematodes</categorytree> |
| − | [[:Category:Sheep Nematodes|Sheep Nematodes]]
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| − | [[:Category:Goat Nematodes|Goat Nematodes]]
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| − | [[:Category:Horse Nematodes|Horse Nematodes]]
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| − | [[:Category:Pig Nematodes|Pig Nematodes]]
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| − | [[:Category:Poultry Nematodes|Poultry Nematodes]]
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| − | [[Small Animals]]
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| − | [[Endoparasites - Donkey|Donkey Endoparasites]]
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| − | Occlusion of pancreatic ducts sometimes happens [[Pancreas Parasitic - Pathology]]
| + | Nematodes of Different Species |
| | + | :[[:Category:Cattle Nematodes|Cattle Nematodes]] |
| | + | :[[:Category:Sheep Nematodes|Sheep Nematodes]] |
| | + | :[[:Category:Goat Nematodes|Goat Nematodes]] |
| | + | :[[:Category:Horse Nematodes|Horse Nematodes]] |
| | + | :[[:Category:Pig Nematodes|Pig Nematodes]] |
| | + | :[[:Category:Avian Nematodes|Avian Nematodes]] |
| | + | :[[:Category:Dog Nematodes|Dog Nematodes]] |
| | + | :[[:Category:Cat Nematodes|Cat Nematodes]] |
| | + | :[[Rabbit Nematodes]] |
| | + | :[[:Category:Rodent Nematodes|Rodent Nematodes]] |
| | + | :[[Endoparasites - Donkey|Donkey Endoparasites]] |
| | + | </b></big> |
| | + | |logo = Nematode logo.jpg |
| | + | }} |
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| − | [[Category:Helminths]] | + | [[Category:Helminths]] [[Category:To_Do_-_Parasites]] |