Aquatic Parasite Observatory

Amidostomum acutum (Lundahl, 1848)

    • Species Name: Amidostomum acutum (Lundahl, 1848)
    • Synonyms: None
    • Taxonomy: (Lundahl, 1848) Animalia, Nematoda, Secernentea, Strongylida, Amidostomatidae, Amidostomum acutum
    • Description: Genus description of Amidostomum (Railliet and Henry, 1909). Buccal capsule: internal dimensions 0.025-0.030mm; external dimensions 0.034-0.056mm with 3 teth. Synlophe absent. Male: Spicules with 2-4 branches at distal end; 0.186-0.376mm long. Gubernaculum 0.089-0.160mm long (Gibbons, 2010; Kavetska et al., 2011).
    • Life Cycle: Amidostomum sp. and Epomidiostomum sp. have a direct life cycle in which the infective parasite larvae invade a single host animal for development to reproductive maturity. Embryonated eggs are passed in the feces of an infected host bird. First stage larvae hatch from the eggs into the surrounding environment in about 24–72 hours, depending on the ambient temperature. These larvae molt twice after they hatch, and the time between molts also depends on the temperature. Larvae are quite resilient, surviving low temperatures and even freezing; they do not, however, survive drying. After a bird ingests the larvae, most commonly when a bird feeds or drinks, they enter the gizzard and burrow into its surface lining where they molt again before they become adult worms. Adult worms become sexually mature in about 10–15 days after the final molt, and females shed eggs within 15–20 days. The development from egg to adulthood may take as few as 20 days or as many as 35 days depending on environmental conditions. Once a bird is infected, it can harbor gizzard worms for several years” (Friend and Franson, 1999).
    • Sources: Gibbons, L.M. 2010. Keys to the Nematode Parasites of Vertebrates: Supplementary Volume, p. 99.

      Kavetska, K.M., Królaczyk, K., Stapf, A., Grzesiak, W., Kalisińska, E., and Pilarczyk, B. 2011. Revision of the Species Complex Amidostomum acutum (Lundahl, 1848) (Nematoda: Amidostomatidae). Parasitology Research, Vol. 109, No. 1, p. 105–117.

    • Friend, M. and Franson, J.C. 1999. Field Manual of Wildlife Disease — General Field Procedures and Diseases of Birds. US dept. of the interior. Accessed online at on Jan 20, 2016. Chapter 32.
    • APO Parasite Records: (by Life Cycle)

Parasite Images:

  • University of Colorado Boulder