Order TETRAPHYLLIDEA Carus, 1863

Acanthobothrium thomasae [from Campbell & Beveridge 2002]

© Copyright Ian Beveridge. Melbourne University.

Museums

Regional Maps

Introduction

Tetraphyllidean cestodes are generally characterised by the presence of a scolex with four bothridia, segments with vitelline follicles arranged in two lateral bands, a lateral genital pore with the vagina entering the genital atrium anterior to the cirrus sac, and a medial tubular uterus. However, considerable variation occurs on this basic plan. The scolex may lack bothridia and possess instead four sessile glandular disks, may be cushion-like with a velum or consist of a single apical sucker and the vitelline follicles may be scattered. All members of the order are parasitic in the spiral valves of elasmobranchs or holocephalans (Euzet 1994). Cladistic studies of the Tetraphyllidea (Caira et al. 1999, 2001) have provided evidence to suggest that the Tetraphyllidea is not a monophyletic assemblage. Precise relationships, however, are unclear and the classification of Euzet (1994) is followed here.

Euzet (1994) recognised eight families within the order, Cathetocephalidae Dailey & Overstreet, 1973; Chimaerocestidae Williams & Bray, 1984; Dioecotaeniidae Schmidt, 1969; Disculicepitidae Joyeux & Baer, 1936; Litobothriidae Dailey, 1969; Onchobothriidae Braun, 1900; Phyllobothriidae Braun, 1900; and Prosobothriidae Baer & Euzet, 1955. Four of these (Cathetocephalidae, Litobothriidae, Onchobothriidae and Phyllobothriidae) have been reported from Australian elasmobranchs. Specimens of the Disculicepididae are present in the collections of the South Australian Museum, but have not been formally reported. In addition, large collections of Australian tetraphyllideans have been made but await identification. Thus, the current lists are unlikely to give a true indication of the extent of the Australian fauna.

General References

Caira, J.N., Jensen, K. & Healy, C.J. 1999. On the phylogenetic relationships among tetraphyllidean, lecanicephalidean and diphyllidean tapeworm genera. Systematic Parasitology 42: 77-151

Caira, J.N., Jensen, K. & Healy, C.J. 2001. Interrelationships among tetraphyllidean and lecanicephalidean cestodes. pp. 135-138 in Littlewood, D.J.T. & Bray, R.A. (eds). Interrelationships of the Platyhelminthes. London, UK : The Systematics Association, Taylor & Francis 356 pp.

Euzet, L. 1994. Order Lecanicephalidea Wardle & McLeod, 1952. pp. 195-204 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.