Identification of nematodes Trichostrongylus colubriformis (Nematoda, Trichostrongylidae) using morphological and metric characters

V. Yevstafieva; O. Natiahlyi; V. Melnychuk; L. Nagorna; F.  Alali; L. Korchan; S. Kravchenko; O. Titarenko

doi:10.15421/012609

V. Yevstafieva Poltava State Agrarian University
O. Natiahlyi Poltava State Agrarian University
V. Melnychuk Poltava State Agrarian University
L. Nagorna Sumy National Agrarian University
F. Alali University of Kerbala
L. Korchan Poltava State Agrarian University
S. Kravchenko Poltava State Agrarian University
O. Titarenko Poltava State Agrarian University

Keywords: Trichostrongyloidea, zoonotic parasites, species differentiation, diagnostics, sheep.

Abstract

The genus Trichostrongylus Looss, 1905 (Nematoda: Trichostrongylidae) includes gastrointestinal parasitic nematodes with a direct life cycle, which are recorded worldwide. Helminths affect animals and also have zoonotic potential. Trichostrongylus colubriformis (Giles, 1892) Ransom, 1911 can infect humans. Therefore, accurate identification of trichostrongylid species is one of the most important areas of research and is based on a detailed description of morphological characters and metric parameters of adult nematodes. The objective of the research was to describe the morphometric identification characters of male and female nematodes of the species T. colubriformis isolated from sheep in Ukraine, and to compare other published data with our own results. Differential morphological keys for male T. colubriformis include the structural features of the caudal bursa, the presence of boat-shaped, unequal-sized spicules with a root and triangular process at the ends and wings, as well as the wavy shape of the gubernaculum. In females, the specific features include the structural features of the tail end, and the vulva and its location. Eigh t een morphometric parameters were determined in males, and 13 in females, of which seven and nine parameters, respectively, characterize the general structure of the body such as length and width in different areas, the location of the excretory opening and caudal bursa in males, and the anal opening and the length of the tail end in females. Eleven metric parameters of the male repr o ductive system were described , including the length of the caudal bursa, the size of the spicules and their morphological comp o nents, and the gubernaculum. In females, four metric para m eters were described, which characterize the length of the vulva slit, its location , and the length of the ovejector with sphincters. In addition, t he sizes of the eggs located in the uterine cavity were determined. The obtained results expand and deepen the existing knowledge about the taxonomic features of both males and females of T. colubriformis nematode.

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