MORPHOLOGY: Scolex in the form of a transversely expanded fleshy organ consisting of an apical pad (with or without a median transverse aperture), a band bearing numerous papillae distally, and a rugose base, without bothridia, bothria, suckers and armature. Spherical chambers and transverse channels containing host red and white blood cells, respectively, seen in the scolex of 1 species. Proglottids euapolytic or anapolytic, hermaphroditic, with multiple testes. Ovary posterior, bilobed in cross-section. Vitellaria follicular and circumcortical, vagina opening anterior to cirrus sac. Genital pores lateral, uterus tubular to sacciform, pre-formed uterine pore lacking. Multistrobilation observed in some species.

DIVERSITY: Only 6 described species: 5 species of Cathetocephalus and 1 species of Sanguilevator. A single family, Cathetocephalidae, is currently recognized.

PHYLOGENETIC RELATIONSHIPS: The order is very likely monophyletic, and appears to be the sister-group to a subset of taxa currently considered to belong in the Tetraphyllidea.

DEFINITIVE HOSTS: Parasites of carcharhiniform sharks, primarily Carcharhinidae (whaler sharks), but several records from Sphyrnidae (hammerhead sharks) are known.

SITE IN DEFINITIVE HOST: Spiral intestine.

GEOGRAPHIC DISTRIBUTION: Tropical and subtropical waters, specifically Gulf of Mexico, Lake Nicaragua, coastal Argentina, Gulf of California, coastal Australia, South China Sea off the northern coast of Borneo.

LIFE-CYCLES: Life-cycle completely unknown.

Selected References:

Dailey, M. D. and R. M. Overstreet. Cathetocephalus thatcheri gen. et sp. n. (Tetraphyllidea: Cathetocephalidea fam. n.) from the bull shark: a species demonstrating multistrobilization. Journal of Parasitology 59: 469-473. PDF

Schmidt, G. D. and I. Beveridge. 1990. Cathetocephalus australis n. sp. (Cestoidea: Cathetocephalidae) from Australia, with a proposal for Cathetocephalidea n. ord. Journal of Parasitology 76: 337-339. PDF

Caira, J. N., J. Mega, and T. R. Ruhnke. 2005. An unusual blood sequestering tapeworm (Sanguilevator yearsleyi n. gen., n. sp.) from Borneo with description of Cathetocephalus resendezi n. sp. from Mexico and molecular support for the recognition of the order Cathetocephalidea (Platyhelminthes: Eucestoda) International Journal for Parasitology 35: 1135-1152. PDF

Taxon Coordinator:

Dr. Janine N. Caira

University of Connecticut
Department of Ecology and Evolutionary Biology
75 N. Eagleville Rd., Unit 3043
Storrs CT 06269-3043
U.S.A.
E-MAIL: janine.caira@uconn.edu