Skip to main content
Log in

Discriminant analysis as a method for the numerical evaluation of taxonomic characters in male trichurid nematodes

  • Published:
Systematic Parasitology Aims and scope Submit manuscript


Samples of males of Trichuris ovis (Abildgaard, 1795), T. skrjabini Baskakov, 1924, T. sylvilagi Tiner, 1950, T. suis (Schrank, 1788) and T. trichiura (L., 1771) were compared on the basis of 15 morphometric characters. An analysis of their variability, correlations and a discriminant analysis yielded information on the diagnostic value of these characters and on the best combination of characters necessary for the successful differentiation of the species studied. The morphological similarity of the species studied was also assessed. The length and width of the spicule and body length proved to be the best diagnostic characters for the trichurid males studied. They permitted fairly reliable differentiation of the species T. ovis, T. skrjabini and T. sylvilagi. The species which exhibited the greatest similarity, T. suis and T. trichiura, were frequently misidentified using these features only but could be readily differentiated using seven characters.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others


  • Beer, R.J.S. (1976) The relationship between Trichuris trichiura (Linnaeus, 1758) of man and Trichuris suis (Schrank, 1788) of the pig. Research in Veterinary Science, 20, 47–54.

    Google Scholar 

  • Bray, R.A. & des Clers, S.A. (1992) Multivariate analyses of metrical features in the Lepidapedon elongatum (Lebour, 1908) species-complex (Digenea, Lepocreadiidae) in deep and shallow water gadiform fishes of the NE Atlantic. Systematic Parasitology, 21, 223–232.

    Google Scholar 

  • Gagarin, V.G. (1972) Analysis of the species structure of trichocephalids of ruminants, registered in the Soviet Union. Trudy Vsesoiuznogo Instituta Gelmintologii imeni K.I. Skrjabina, 19, 39–57. (In Russian).

    Google Scholar 

  • Gagarin, V.G. (1974) Critical evaluation of measured characters in the differentiation of helminth species (on the model of trichocephalids). In: Tokobaev, M.M. (Ed.), Fauna gelmintov životnych i rastenij Kirgizii. Frunze: ILIM, pp. 3–9. (In Russian).

    Google Scholar 

  • Georgi, J.R. & McCulloch, C.E. (1989) Diagnostic morphometry: identification of helminth eggs by discriminant analysis of morphometric data. Proceedings of the Helminthological Society of Washington, 56, 44–57.

    Google Scholar 

  • Hinks, M.I. & Thomas, R.J. (1974) A new record of the occurrence of Trichuris skrjabini Baskakov, 1924, in sheep in Britain. Journal of Helminthology, 48, 33–38.

    Google Scholar 

  • Knight, R.A. (1972) New geographic distribution records of Trichuris skrjabini Baskakov, 1924, in sheep in the United States and measurements of various morphological characters. Proceedings of the Helminthological Society of Washington, 39, 242–244.

    Google Scholar 

  • Knight, R.A. (1984) Morphological differences in Trichuris ovis associated with different host species. The Journal of Parasitology, 70, 842–843.

    Google Scholar 

  • Lýsek, H., Komenda, S, Cuervo Pineda, N. & Hernandez, N.L. (1975) Discriminant analysis in biometrical study of eggs of Trichuris trichiura and Trichuris suis. Acta Universitatis Palackianae Olomucensis, 73, 121–136.

    Google Scholar 

  • Macko, J.K. (1983) To the problem of morphospecies, taxospecies and biospecies. I. The establishment of species of the biomorphospecies and biotaxospecies types. Helminthologia, 20, 13–20.

    Google Scholar 

  • Macko, J.K. (1985) On the problem of morphological, taxonomical and biological species. II. Some methods of species determination. Folia parasitologica, 32, 1–10.

    Google Scholar 

  • Manly, B.F.J. (1986) Multivariate statistical methods: a primer. London, New York: Chapman and Hall.

    Google Scholar 

  • Mayr, E., Linsley, E.G. & Usinger, R.L. (1953) Methods and principles of systematic zoology. New York, Toronto, London: McGraw-Hill Book Company Inc., 336 pp.

    Google Scholar 

  • Rickard, L.G. & Bishop, J.K. (1991) Redescription of Trichuris tenuis Chandler, 1930, from llamas (Lama glama) in Oregon with a key to the species of Trichuris present in North American ruminants. The Journal of Parasitology, 71, 70–75.

    Google Scholar 

  • Simpson, G.G., Roe, A. & Lewontin, R.C. (1960) Quantitative zoology. Habana: Vedado, 440 pp.

    Google Scholar 

  • Skrjabin, K.I., Shikhobalova, N.P. & Orlov, I.V. (1957) [Trichocephalidae and Capillariidae of animals and man and the diseases caused by them.] Osnovy Nematodologii, 6, 496 pp.

    Google Scholar 

  • Tenora, F., Staněk, M. & Špakulova, M. (1992) On the possibility of morphological differentiation of Trichocephalus trichiurus (L., 1771) and T. suis (Schrank, 1788) species. Abstracts of Conference “Aktuálne Otázky Humánnej Parazitológie”, Bratislava, July 11–12th, 1992, 65–66.

Download references

Author information

Authors and Affiliations


Rights and permissions

Reprints and permissions

About this article

Cite this article

Špakulová, M. Discriminant analysis as a method for the numerical evaluation of taxonomic characters in male trichurid nematodes. Syst Parasitol 29, 113–119 (1994).

Download citation

  • Accepted:

  • Issue Date:

  • DOI: