Superfamily Heterakoidea
Revised
06/06/26
Chromadoria
Heterakoidea
- The superfamily Heterakoidea is comprised of
ascaridid nematodes that most often parasitize the cecum and large
intestine of amphibians, reptiles, birs, and mammals.
- Stoma with 3 lips, a fused esophago-rhabdion and a conspicuous cheilorhabdion.
- Esophagus with a posterior bulb and a muscular anterior corpus.
- Life cycle usually direct: eggs containing the
infective third-stage juvenile (J3) are ingested by the definitive host,
although for some species, paratenic hosts may be involved.
- Heterakoids are characterized by a pre-cloacal sucker with
well-developed cuticular rim, 2 spicules and a gubernaculum in males.
- Vulva usually located at midbody. Eggs with smooth shells, usually
unembryonated in the uterus.
- Two genera, Ascaridia and Heterakis,
include important parasites of birds, and both impact rearing of commercial
poultry (Jansson et al., 2010; Jimenez-Ruiz, 2024)..
Families:
References
Hodda, M. 2022. Phylum Nematoda: feeding
habits for all valid genera using a new, universal scheme encompassing the
entire phylum, with descriptions of morphological characteristics of the stoma,
a key, and discussion of the evidence for trophic relationships. Zootaxa
5114(1):318-451. https://doi.org/10.11646/zootaxa.5114.1.3
Jansson, D.S., A. Nyman, I. Vågsholm, D. Christensson, et
al. 2010. Ascarid infections in laying hens kept in different housing systems.
Avian Pathology 39: 525–532. doi: 10.1080/03079457.2010.527923
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