Systematic Parasitology

, Volume 67, Issue 3, pp 211–223 | Cite as

A revision of Megalonchos Baer & Euzet, 1962 (Tetraphyllidea: Onchobothriidae), with the description of two new species and transfer of two species to Biloculuncus Nasin, Caira & Euzet, 1997

  • J. N. Caira
  • F. B. Reyda
  • J. D. Mega
Original Paper


The onchobothriid tapeworm genus Megalonchos Baer & Euzet, 1962 is revised and the generic diagnosis amended based on the examination of some of Southwell’s material of M. mandleyi (Southwell, 1927) Baer & Euzet, 1962, the type-specimens of M. dubius Prudhoe, 1969 and M. musteli Prudhoe, 1969, and material of two new species, M. sumansinghai n. sp. and M. shawae n. sp., collected from the snaggletooth shark Hemipristis elongatus off northern Australia. Based on their possession of two pairs of uni-pronged hooks (rather than one pair of bi-pronged hooks) and possession of, rather than lack of, post-vaginal testes, M. dubius and M. musteli are transferred to Biloculuncus Nasin, Caira & Euzet, 1997 as B. dubius (Prudhoe, 1969) n. comb. and B. musteli (Prudhoe, 1969) n. comb. Both new species of Megalonchos differ from M. mandleyi in their possession of conspicuously smaller hooks and shorter cephalic peduncles. The new species are readily distinguished from one another in that, whereas the pores of the axial prongs of the medial and lateral hooks are located well anterior to the middle of the prong in M. sumansinghai n. sp., they are well posterior to the middle of the prongs in M. shawae n. sp. In addition, the base of the lateral hook is longer relative to that of the medial hook in the latter species than it is in the former species. The proglottid anatomy of valid species of Megalonchos is described for the first time, and the lack of post-vaginal testes is confirmed for the genus. In addition, members of this genus appear to be characterised by a sacciform uterus that extends only to the level of the cirrus-sac and an ovary that is H-shaped in frontal view and bilobed in cross-section. Species of Megalonchos have now been reported from two of the eight known species of hemigaleid sharks.


Anterior Margin Vitelline Follicle United States National Parasite Collection Mature Proglottid Nasin 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



Our success in collecting cestodes from specimens of the shark Hemipristis elongatus would not have been possible without the arrangements made by Bill Passey for us to work on the FV Ocean Harvest and thus to examine fresh material of this otherwise difficult to obtain shark species. We very much appreciate the full cooperation we received from the crew and most especially from Captain Ray Passey, who went out of his way to accommodate all of our needs during the three weeks we spent on the vessel. Kirsten Jensen was of enormous assistance with the collection of this material. We thank David Stemmer of the South Australian Museum and Eileen Harris of the Natural History Museum in London for their assistance with the location and loan of specimens. This work was supported in part with funds from NSF PEET awards No. DEB 9521943 and DEB 0118882 to JNC.


  1. Baer, J. G., & Euzet, L. (1962). Revision critique des cestodes tétraphyllides décrits par T. Southwell (1re partie). Bulletin de la Société Neuchâteloise des Sciences Naturelles, 85, 143–172.Google Scholar
  2. Caira, J. N., & Jensen, K. (2001). An investigation of the coevolutionary relationships between onchobothriid tapeworms and their elasmobranch hosts. International Journal for Parasitology, 31, 959–974.CrossRefGoogle Scholar
  3. Caira, J. N., Richmond, C., & Swanson, J. (2005). A revision of Phoreiobothrium (Tetraphyllidea: Onchobothriidae) with descriptions of five new species. Journal of Parasitology, 91, 1153–1174.PubMedCrossRefGoogle Scholar
  4. Caira, J. N., & Ruhnke, T. R. (1990). A new species of Calliobothrium (Tetraphyllidea: Onchobothriidae) from the whiskery shark, Furgaleus macki, in Australia. Journal of Parasitology, 76, 319–324.PubMedGoogle Scholar
  5. Compagno, L. (1984). FAO species catalogue. Vol. 4, Part 2: Sharks of the world. An annotated and illustrated catalogue of shark species known to date (pp. 655). FAO Fisheries Synopsis No. 125. Rome: United Nations Development Programme/Food and Agriculture Organization of the United Nations.Google Scholar
  6. Compagno, L., Dando, M., & Fowler, S. (2005). Sharks of the world (pp. 368). Princeton: Princeton University Press.Google Scholar
  7. Euzet, L. (1994). Order Tetraphyllidea Carus, 1863. In L. F. Khalil, A. Jones, & R. A. Bray (Eds.), Keys to the cestode parasites of vertebrates (pp. 149–194). Wallingford: CAB International.Google Scholar
  8. Goldstein, R. J. (1967). The genus Acanthobothrium van Beneden, 1849 (Cestoda: Tetraphyllidea). Journal of Parasitology, 53, 455–483.PubMedCrossRefGoogle Scholar
  9. Healy, C. J. (2003). A revision of Platybothrium Linton, 1890 (Tetraphyllidea: Onchobothriidae), with a phylogenetic analysis and comments on host-parasite associations. Systematic Parasitology, 56, 85–139.PubMedCrossRefGoogle Scholar
  10. Healy, C. J., Scholz, T., & Caira, J. N. (2001). Erudituncus n. gen. (Tetraphyllidea: Onchobothriidae) with a redescription of E. musteli (Yamaguti, 1952) n. comb. and comments on its hook homologies. Journal of Parasitology, 87, 833–837.PubMedCrossRefGoogle Scholar
  11. Nasin, C. S., Caira, J. N., & Euzet, L. (1997). Analysis of Calliobothrium (Tetraphyllidea: Onchobothriidae) with descriptions of three new species and erection of a new genus. Journal of Parasitology, 83, 714–733.PubMedCrossRefGoogle Scholar
  12. Prudhoe, S. (1969). Cestodes from fish, birds and whales. B.A.N.Z. Antarctic Research Expedition 1924–1931, Series B, 8, 171–193.Google Scholar
  13. Southwell, T. (1925). A monograph on the Tetraphyllidea with notes on related cestodes. Memoirs of the Liverpool School of Tropical Medicine, 2 (New Series), 1–368.Google Scholar
  14. Southwell, T. (1927). On a collection of cestodes from marine fishes of Ceylon and India. The Annals of Tropical Medicine and Parasitology, 21, 351–373.Google Scholar
  15. Southwell, T. (1930). Cestoda. Vol. I. In J. Stephenson (Ed.), The fauna of British India, including Ceylon and Burma (pp. 391). London: Taylor and Francis.Google Scholar
  16. Williams, H. H. (1969). The genus Acanthobothrium Beneden, 1849 (Cestoda: Tetraphyllidea). Nytt Magasin for Zoologi, 17, 1–56.Google Scholar

Copyright information

© Springer Science+Business Media B.V. 2007

Authors and Affiliations

  1. 1.Department of Ecology and Evolutionary BiologyUniversity of ConnecticutStorrsUSA

Personalised recommendations