Superfamily: Strongyloidea

Revised 10/15/25

Lungworms 

Classification:
 

   Chromadorea

Chromadoria

Recent Clessification	Alternative Classification	Relationships among species, genera, and even families, within the Nematoda are becoming clearer as morphological, morphometric, and life history features are considered along with molecular-based phylogenies. However, there remain differences of opinion among experts regarding classifications above the family level.  Such differences are apparent in the classification in the Order Strongylida or the consideration of suborders of the Strongylida as suborders of the Rhabditida.
Rhabditida	Strongylida
Rhabditina	Strongylina
Rhabditomorpha
Strongyloidea	Strongyloidea

           Strongyloidea  Weinland, 1858

Superfamily Strongyloidea includes nematodes in the families:

• Chabertiidae
• Deletrocephalidae
• Strongylidae
• Syngamidae

Characteristics:

• Parasites of animals; direct lifecycles, not requiring an intermediate host.
• Eggs passed in feces and hatch as a free-living microbivorous L1 which feed on bacteria, develop and undergo two molts to the infective L3 stage. that develop and molt in 12 days to an L2 that molts finally to the infective L3.
• The L3 retains the cuticle of the L2 as a sheath and are ingested by grazing animals.  The L3 become exsheathed in the gastro-intestinal tract of the infected host.
• Depending on the species, adult worms live in the mucosal surface of the intestine (hookworms), respiratory system (gapeworms), or in the renal area (kidney worms) of the host.
• General morphology:
  • a large anteriorly buccal capsule, stoma surrounded by a corona
  • dorsal esophageal gland opening on the inner wall  of the buccal capsule, sometimes in a ridge
  • teeth may be present at the base of the buccal capsule to separate clumps of mucosa.
  • males with a well-developed bursa and long,  slender spicules.
  • females with vulva close to the anus and an anteriorly directed uterus.

Ref: Marchiondo et al., 2020

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References

Beveridge, I., Spratt, D.M.  and Durette-Desset, M-C. 2014. Order Strongylida (Railliet and Henry, 1913). In Schmidt-Raesa, A. (ed). Handbook of Zoology: Gastroctricha, Cycloneurelia and Gnathifera. Vol 2. Nematoda. De Gruyter, Berlin

Marchiondo, A.A., Cruthers L.R., Reinemeyer, C.R.  2020. Nematoda, Strongyloidea. Chapter 2 in Marchiondo, Cruthers and Fourie (eds) Parasiticide Screening Vol 2. Academic Press.

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