Skip to main content
    • Aa
    • Aa

Morphological and molecular characterization of tetraphyllidean merocercoids (Platyhelminthes: Cestoda) of striped dolphins (Stenella coeruleoalba) from the Western Mediterranean

  • C. AGUSTÍ (a1), F. J. AZNAR (a1), P. D. OLSON (a2), D. T. J. LITTLEWOOD (a2), A. KOSTADINOVA (a1) (a3) and J. A. RAGA (a1)...

Two types of tetraphyllidean merocercoids, Phyllobothrium delphini and Monorygma grimaldii, are well known from most cetaceans world-wide. The role of cetaceans in the life-cycle of these merocercoids is unclear because their specific identity is as yet unknown. The problem is compounded by poor descriptions of both merocercoids. We used light and scanning electron microscopy, and histological techniques to provide a thorough description of merocercoids collected from 11 striped dolphins, Stenella coeruleoalba, from the Spanish Mediterranean. We also described, for the first time, specimens of P. delphini with immature proglottides. Our merocercoids were morphologically similar to those described previously, except in the structure of the apical organ. Intra- and inter-sample variability in the morphology of the apical organ suggested that it degenerates during larval development. A subsample of 16 specimens of P. delphini and M. grimaldii was characterized for the D2 variable region of the large subunit ribosomal RNA gene (LSU) and compared with published tetraphyllidean cestode LSU sequences. P. delphini showed 2 unique signatures that differed from one another by a single base, whereas all sequences of M. grimaldii were identical. This suggests that each type may represent a single species, contrary to previous speculations based on morphological data. All merocercoid specimens formed a clade together with Clistobothrium montaukensis. Based on the low degree of divergence, all specimens of this clade are predicted to be congeneric.

Corresponding author
Marine Zoology Unit, Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, P.O. Box 22085, 46071 Valencia, Spain. Tel: +34 96 354 36 85. Fax: +34 96 354 37 33. E-mail:
Linked references
Hide All

This list contains references from the content that can be linked to their source. For a full set of references and notes please see the PDF or HTML where available.

BESTER, M. N. ( 1989). Endoparasites of the subantarctic fur seal Arctocephalus tropicalis from Gough Island. South African Journal of Zoology24, 363365.

BRICKLE, P., OLSON, P. D., LITTLEWOOD, D. T. J., BISHOP, A. & ARKHIPKIN, A. I. ( 2001). Parasites of Loligo gahi from waters off the Falkland Islands, with a phylogenetically based identification of their cestode larvae. Canadian Journal of Zoology79, 22892296.

CAIRA, J. N., JENSEN, K. & HEALY, C. J. ( 1999). On the phylogenetic relationships among tetraphyllidean, lecanicephalidean and diphyllidean tapeworm genera. Systematic Parasitology42, 77151.

CHAMBERS, C. B., CRIBB, T. H. & JONES, M. K. ( 2000). Tetraphyllidean metacestodes of teleosts of the Great Barrier Reef, and the use of in vitro cultivation to identify them. Folia Parasitologica47, 285292.

CHERVY, L. ( 2002). The terminology of larval cestodes or metacestodes. Systematic Parasitology52, 133.

HAMILTON, K. A. & BYRAM, J. E. ( 1974). Tapeworm development: the effects of urea on a larval tetraphyllidean. Journal of Parasitology60, 2028.

HUELSENBECK, R. & RONQUIST, F. ( 2001). MrBayes: Bayesian inference of phylogenetic trees. Bioinformatics17, 754755.

LINTON, E. ( 1905). Notes on cestode cyst, Taenia chamissonii, new species, from a porpoise. Proceedings of the United States National Museum28, 819823.

LINTON, E. ( 1922). A new cestode from the maneater and mackerel sharks. Proceedings of the United States National Museum61, 116.

OLSON, P. D., LITTLEWOOD, D. T. J., BRAY, R. A. & MARIAUX, J. ( 2001). Interrelationships and evolution of the tapeworms (Platyhelminthes: Cestoda). Molecular Phylogenetics and Evolution19, 443467.

OLSON, P. D., CRIBB, T. H., TKACH, V. V., BRAY, R. A. & LITTLEWOOD, D. T. J. ( 2003). Phylogeny and classification of the Digenea (Platyhelminthes: Trematoda). International Journal for Parasitology33, 733755.

POSADA, D. & CRANDALL, K. A. ( 1998). Modeltest: testing the model of DNA substitution. Bioinformatics14, 817818.

REYDA, F. & OLSON, P. D. ( 2003). Cestodes of Peruvian freshwater stingrays. Journal of Parasitology89, 10181024.

RUHNKE, T. R. ( 1993). A new species of Clistobothrium (Cestoda: Tetraphyllidea), with an evaluation of the systematic status of the genus. Journal of Parasitology79, 3743.

RUHNKE, T. R. ( 1996). Taxonomic resolution of Phyllobothrium van Beneden (Cestoda: Tetraphyllidea) and a description of a new species from the leopard shark Triakis semifasciata. Systematic Parasitology33, 112.

SOUTHWELL, T. & WALKER, A. J. ( 1936). Notes on a larval cestode from a fur seal. Annals of Tropical Medicine and Parasitology30, 91100.

WALKER, W. A. ( 2001). Geographical variation of the parasite, Phyllobothrium delphini (Cestoda), in Dall's porpoise, Phocoenoides dalli, in the Northern North Pacific, Bering Sea and Sea of Okhotsk. Marine Mammal Science17, 264275.

Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

  • ISSN: 0031-1820
  • EISSN: 1469-8161
  • URL: /core/journals/parasitology
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Full text views

Total number of HTML views: 5
Total number of PDF views: 14 *
Loading metrics...

Abstract views

Total abstract views: 85 *
Loading metrics...

* Views captured on Cambridge Core between September 2016 - 20th August 2017. This data will be updated every 24 hours.