Syphacia muris		Contents		Rev 23-10-2025
Rat Pinworm; Threadworm		Classification
		Morphology and Anatomy		Life Cycle
Return to Syphacia Menu		Distribution		Ecosystem Functions and Services
		Feeding		Management
Return to Oxyuridae Menu		Biology and Ecology		References
		Go to Nemaplex Main Menu		Go to Dictionary of Terminology

Classification:

Chromadorea
Chromadoria

           Rhabditida 

                       Spirurina

                          Oxyuroidea

                   Oxyuridae

Syphaciinae

 

            Syphacia muris (Yamaguti, 1935) Yamaguti, 1941

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Morphology and Anatomy:

Differ from S. obvelata in the l;ength of the male spicule and size of the eggs.

Male:

• Length 1.2-1.3 mm x 100 um wide
• Spicule 56um long, 3 um wide
• Gubrenaculum transversely directed, 36 umn long  with a distal barb
• Tail 150 um long with 3 ventral cuticular bossed or mamalons.

Female:

• Length 2.8-3.4 mm, width 180-425 um; tail 420-460 um long
•  Eggs with one side flattened, 72-82 x 25-36 um. Embryo undifferentiated in utero.

Ref: Marchiondo, 2020

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Distribution:

Wordwide, parasite of the large intestine of white rats.

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Feeding:

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Hosts:

Rats

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Life Cycle:

Lifecycle direct,  similar to that of S. obvelata

• Infective eggs with an adhesive coating are deposited in the perianal region of the hoste by the female worm protruding its posterior end from the anus of the infected host.
•  Eggs are ingested byrats from the perianal region of other mice or in contaminated food; they hatch in the small intestine within 1 h of ingestion.
•  Larvae develop in the cecum.
• Adult males become sexually mature in 5 days and disappear or die after copulation.
• After fertilization, females migrate from the cecum to the large intestine and then to the anus to deposit eggs.
•  The prepatent period is 7-8 days (Marchiondo et al., 2020)/

Ecophysiological Parameters:

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Copyright  1999 by Howard Ferris.
Revised: October 23, 2025.