Species-specific morphological characteristics of adult and embryonic Capillariа obsignata roundworms (Nematoda, Capillariidae)

Abstract
The abundance of Capillaria obsignata Madsen, 1945, the causative agent of chicken capillariasis, was studied in the central region of Ukraine. Differential morphometric characters are determined for adult males and females of C. obsignata. The species-specific variability of its morphological parameters is characterized. New data is received on the meristic characters of C. obsignata eggs extracted from different substrates. The stages of embryonic development are determined in laboratory cultures of these nematodes, taking into account their meristic and morphological changes. Capillaria obsignata parasites are very common at the poultry farms of Poltava and Kyiv regions of Ukraine. Their abundance index is 3.4, and the intensity of infection varies from 3 to 317 specimens. Differential morphometric species-specific characters of adult C. obsignata males are the shape and size of the pseudobursa, spicule, spicule sheath. Adult females of the species can be identified by the shape and size of the vulva, the distance from the esophagus end to the vulva, and the length of the vagina. The meristic characters of nematode eggs, though typical for the species, may change depending on the sampled substrate. The parasite’s embryonic development involves five morphologically and meristically different stages. The invasive larvae of this species developed in the eggs before the 12th day of culturing in laboratory conditions at 25 °С. The invasive larvae’s viability was 90.3 ± 1.5%.
Description
Yevstafyeva. V. A., Stybel. V. V., Sharavara. T. A., Melnychuk. V. V., Yasnolob. I. О., Antipov. А. А., Goncharenko. V. P., Bakhur. T. I. Species-specific morphological characteristics of adult and embryonic Capillariа obsignata roundworms (Nematoda, Capillariidae). Biosystems Diversity, 25(4), 354–360.
Keywords
abundance index; adult roundworm; nematode eggs; differential characters
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