Host-specificity and morphometrics of female Haemonchus contortus, H. placei and H. similis (Nematoda: Trichostrongylidae) in cattle and sheep from shared pastures in São Paulo State, Brazil. Issue 3 (May 2015)

• Record Type: Journal Article
• Authors: Silva, M.R.L.; Amarante, M.R.V.; Bresciani, K.D.S.; Amarante, A.F.T.
• Is Part Of: Journal of helminthology. Volume 89:Issue 3(2015)
• Page Start: 302
• Page End: 306
• Publication Date: 2015-05
• Subjects: Helminthology -- Periodicals; 592.3
• DOI: 10.1017/S0022149X14000078
• Languages: English
• ISSNs: 0022-149X

Abstract

<abstract abstract-type="normal"> <title>Abstract</title> <p>To better evaluate the usefulness of female <italic>Haemonchus</italic> specimens for specific identification, we undertook a detailed analysis of the morphology of a collection of worms obtained from cattle and sheep in shared pastures. Based on the results, we also more precisely evaluated the host-specificity of <italic>Haemonchus contortus, H. placei</italic> and <italic>H. similis</italic> occurring sympatrically in a farm located in the western region of São Paulo State, Brazil. A synlophe analysis was employed to identify the three species of <italic>Haemonchus</italic>. In cattle, the predominant species was <italic>H. similis</italic> (90.9%), followed by <italic>H. placei</italic> (9.1%). With the exception of one <italic>H. placei</italic> specimen, only <italic>H. contortus</italic> was found in sheep. The longest body length was found for <italic>H. placei</italic> specimens, followed by <italic>H. contortus</italic> and then <italic>H. similis.</italic> It was possible to distinguish <italic>H. similis</italic> females from <italic>H. contortus</italic> and <italic>H. placei</italic> on the basis of vulval structure. The synlophe analysis proved to be very useful for identification of <italic>H. contortus, H. placei</italic> and <italic>H. similis</italic> in epidemiological studies involving different species of ruminants in the same pastures. The finding that <italic>H. placei</italic> and <italic>H. similis</italic> were adapted to cattle and that <italic>H. contortus</italic> was adapted to sheep also confirmed the high host-specificity of the three nematodes species.</p> </abstract>