Order TETRABOTHRIIDEA Baer, 1954

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Introduction

Tetrabothriidean cestodes have a scolex armed with four bothridia, and the vitelline gland compact and anterior to the ovary, a unique situation within the Cestoda. The uterus is a transverse tube lying dorsal to the ovary. Tetrabothriideans are intestinal parasites of marine birds and mammals (Hoberg 1994).

The taxonomic position of the Tetrabothriidea has been the subject of ongoing dispute (Hoberg 1994). The family was included within the Cyclophyllidea in earlier classifications (e.g. Schmidt 1986), a position precluded by the possession of bothridia rather than suckers on the scolex, and has in the past also been included in the Tetraphyllidea since the scolex bears four bothridia, a principal feature of most species of this order. However, in the Tetraphyllidea the vitelline follicles occur in lateral bands and the uterus is median (for details see Hoberg 1994). Morphogenesis of the scolex of tetrabothriideans however indicates clear affinities with the Tetrabothriidea Hoberg, 1987). Current evidence therefore suggests that this group of cestodes evolved by host switching to mammals and birds from species which are primarily parasitic in elasmobranchs.

A single family, the Tetrabothriidae Linton, 1891, is recognised by most authors.

General References

Hoberg, E.P. 1987. Recognition of larvae of the Tetrabothriidae (Eucestoda): implications for the origins of tapeworms in marine homeotherms. Canadian Journal of Zoology 65: 997-1000

Hoberg, E.P. 1994. Order Tetrabothriidea Baer, 1954. pp. 295-304 in Khalil, L.F., Jones, A. & Bray, R.A. (eds). Keys to the Cestode Parasites of Vertebrates. Wallingford, UK : Commonwealth Agriculture Bureaux International 751 pp.

Schmidt, G.D. 1986. Handbook of Tapeworm Identification. Boca Raton, Florida : CRC Press 675 pp.

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