Rev: 10/14/2025
Capillariidae
Capillaria Zeder, 1800
A nematode genus of parasites of birds, fish and mammals (rodents and others).
Per Moravec (1982) species in the genus Capillaria are assigned to six subgenera based on morphological characters and host associations. He suggested criteria for separation into subgenera based on morphological characteristics, including features of: caudal alae, bursa, lobular projections, spicule, and cirrus (spicular sheath) in the male, and presence or absence of a vulvar appendage, egg shape, and ornamentation in the female.
Stichosomes occur in two orders of the Nematoda: Trichinellida, with at least six families, and Mermithida, with two families. Recent phylogenetic analysis based on a synthesis of molecular and morphological data suggest that the stichosome may be an example of parallel evolution in the Trichinellida and Mermithida (De Ley and Blaxter, 2002; Ferris, 2007).
The pharynx is narrow and thin-walled anteriorly and posteriorly, is surrounded by unicellular, glandular stichocytes, each with a duct into the pharyngeal lumen.
The pharynx extends one-fourth to nine-tenths of the body length in various taxa and is almost devoid of musculature. The region of the pharynx surrounded by stichocytes is known as the stichosome.
Food Sources and Feeding strategies for the genus Capillaria
Parasites of birds, fish, mammals, humans. Most species described are parasites of either fish or birds.
Genus Capillaria is the causal agent of capillariasis in humans and other mammals, and in fish and birds. Capillaria hepatica causes hepatic capillariasis (infection of the liver) and Capillaria philippinensis causes intestinal capillariasis.
del Rosario Robles et al (2912) point out the importance of the anatomical site of host infection in considering the phylogeny of mammalian capillariids. For example, species of Liniscus are only found in the urinary bladder, species of Calodium are only found in the liver, and species of Eucoleus are typically found in the esophagus and stomach. Most of the species in Capillaria are found in the small and large intestines and the cecum. Genetic studies are needed to confirm whether morphology and sid site specificity of these genera parallel the evolution of the family.
Homoxeneous life cycle, intermediate host not used or, in other species. heteroxeneous with earthworms as intermediate hosts (Marchiondo et al., 2020)
del Rosario Robles, M., Bain, O., Navone, G.T. 2012. Desaiption of a new Capillariinae (Nematoda: Trichuridae) from Scapteromys aquaticus (Ceicetidae: Sigmodontinae) from Buenas Aires, Argentina, J. Parasitol.98:627-629.
Moravec, F. 1982. Proposal of a new systematic arrangement of nematodes of the family Capillaridae. Folia Parasitologica 29: 119� 132
Marchiondo, A.A., Cruthers, L.R., Zarlenga, D.S., Yazwinski, T,A, 2020. Nematoda, Trichinelloidea. Chapter 2 in Marchiondo, Cruthers and Fourie (eds) Parasiticide Screening Vol 2. Academic Press.