Changes

[[Image:Trichostrongylus.jpg|thumb|right|150px|''Trichostrongylus'' - Joaquim Castellà Veterinary Parasitology Universitat Autònoma de Barcelona]]

[[Image:Trichostrongylus.jpg|thumb|right|150px|''Trichostrongylus'' - Joaquim Castellà Veterinary Parasitology Universitat Autònoma de Barcelona]]

 

*Most members of this superfamily look like short lengths of cotton (typically 0.5-2cm)

The life cycle of a ''trichostrongyloidea'' are direct, and infection is through ingestion of L3. They are a bursate group, with ''Dictyocaulus'' forming the only exception.  Important genera include ''Ostertagia'', ''Haemonchus'' and ''Trichostrongylus.''

*The spicules of each species have a characteristic shape

== General Life-Cycle ==

== General Life-Cycle ==

*The egg is approximately 80µm long, oval, thin-shelled, contains 4-16cells (i.e. it is a typical strongyle egg)

The egg is approximately 80µm long, oval, thin-shelled, and containing 4-16 cells, so is a typical strongyle egg.

*Egg → L1 → L2 → L3 (this occurs on the ground)

 

*L1 and L2 feed on bacteria

Egg → L1 → L2 → L3 occurs on the ground.  L1 and L2 feed on bacteria, and L3 is exsheathed and represents the infective stage. L3 cannot feed, but do contain a finite amount of stored food to provide energy for movement.  Infection is via ingestion of the L3.  L3 → L4 → adult, these stages generally occur in the stomach or small intestine.

*L3 is the infective stage

 

*L3 is ensheathed (i.e. the L2 cuticle is retained after moulting as an "outer skin")

Parasitic development initially occurs in gastric glands or intestinal crypts, species dependent.  Adults are generally found on the mucosal surface, and the prepatent period is typically about 3 weeks.

*L3 cannot feed, but contains a finite amount of stored food to provide energy for movement

*Infection is by ingestion of the L3

*L3 → L4 → adult (this occurs in the stomach or small intestine)

*Parasitic development initially occurs in gastric glands or intestinal crypts (depending on species)

*Adults are situated on the mucosal surface  

*The prepatent period is typically about 3 weeks