Difference between revisions of "Nematode Life Cycle"

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[[Image:Soybean cyst nematode EM.jpg|thumb|right|150px|Soybean Cyst Nematode and Egg, Scanning Electron Micrograph - Wikimedia Commons]]
 
[[Image:Soybean cyst nematode EM.jpg|thumb|right|150px|Soybean Cyst Nematode and Egg, Scanning Electron Micrograph - Wikimedia Commons]]
 
=== General Life-Cycle ===
 
=== General Life-Cycle ===
 
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*The basic life-cycle is very simple:
In the complete nematode life cycle there are four larval stages, followed by the immature adult.
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**egg → L1 → L2 → L3 → L4 → adult
 
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*With a moult in between each larval stage
egg → L1 → L2 → L3 → L4 → adult
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*But there are many variations on this theme
 
 
The '''direct life cycle''' is the most common.  The free living larval stages undergoes two transformations after hatching.  Infection occurs when the host ingests the free L3.
 
 
 
The '''indirect life cycle''' involves an intermediate host.  The first two moults usually occur in the intermediate host.  Infection of the definitive host is either via ingestion of the intermediate host or by inoculation of the L3 by an intermediate host such as an insect.
 
  
 
=== Nematode Eggs ===
 
=== 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
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
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. <u>A typical strongyle egg is approximately '''80µm''' long.</u>
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[[Category:Nematodes]]
 
 
{{Learning
 
|literature search = [http://www.cabdirect.org/search.html?q=de%3A%28nematodes%29+AND+title%3A%28%22Life+Cycle%22%29 Nematode Life Cycle publications]
 
|Vetstream = [https://www.vetstream.com/canis/search?s=nematode Nematode]
 
}}
 
 
 
 
 
{{review}}
 
 
 
==Webinars==
 
<rss max="10" highlight="none">https://www.thewebinarvet.com/parasitology/webinars/feed</rss>
 
 
 
[[Category:Nematodes|B]]
 
 
 
[[Category:Expert_Review]]
 

Revision as of 10:12, 21 May 2010

Soybean Cyst Nematode and Egg, Scanning Electron Micrograph - Wikimedia Commons

General Life-Cycle

  • The basic life-cycle is very simple:
    • egg → L1 → L2 → L3 → L4 → adult
  • With a moult in between each larval stage
  • But there are many variations on this theme

Nematode Eggs

  • These vary greatly in appearance and are very useful for diagnosis as they can often be detected and counted in faecal samples
  • 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