Scanning electron micrograph (SEM) image of scolex of Echinobothrium sp.; SEM of bothria of Echinobothrium sp.; SEM of bothria of Echinobothrium rhynchobati; SEM of bothria of Echinobothrium sp.; examples of hosts of diphyllideans: Neotrygon kuhlii and Raja sp. (top), Mustelus schmitti (bottom). (Photos courtesy of V. Ivanov)
Scolex consisting of 2 bothria and a cephalic peduncle with or without spines. Apical rostellum present or absent. Proglottids hermaphroditic and acraspedote. Testes anterior to ovary. Genital pores mid-ventral. Ovary posterior, bilobed in cross section. Vitelline follicles arranged in lateral bands or circumcortically. Uterus sacciform, without a preformed uterine pore.
The order currently includes 3 genera and 49 valid species classified into 2 families.
Molecular and morphological data suggest that the diphyllideans are monophyletic and are sister group to the Trypanorhyncha.
Parasites of elasmobranchs. Diphyllideans have been found in a number of batoid families (Rajidae, Myliobatidae, Rhinobatidae) and less frequently in a diversity of shark families (Triakidae, Hemiscylliidae and Scyliorhynidae.
Spiral intestine.
Cosmopolitan (Atlantic, Pacific and Indian Oceans, Mediterranean and Red Seas).
No record of a complete diphyllidean life-cycle has been published; however, there exist observations on a number of larval stages (plerocerci) of species of Echinobothrium and Ditrachybothridium, which occur in various organs of marine crustaceans and molluscs.
Selected References:
Khalil, L. F. 1994. Order Diphyllidea van Beneden in Carus, 1963. pp. 45-49. In Khalil, L. F., Jones, A., Bray, R. A. (Eds.) Key to the cestode parasites of vertebrates. CAB International, Wallingford, U.K. PDF
Caira, J. N., K. Jensen, and C. J. Healy. 1999. On the phylogenetic relationships among the tetraphyllidean, lecanicephalidean, and diphyllidean tapeworm genera. Systematic Parasitology 42: 77-151. PDF
Ivanov, V. A. and E. Hoberg. Preliminary comments on a phylogenetic study of the order Diphyllidea van Benden in Carus, 1863. Systematic Parasitology 42: 21-27. PDF
Tyler, G. A. A monograph on the Diphyllidea (Platyhelminths: Cestodes). Bulletin of the University of Nebraska State Museum 20: 142 pp. PDF
Marques, F. P. L., K. Jensen, and J. N. Caira. 2012. Ahamulina n. gen. (Cestoda: Diphyllidea) from the polkadot catshark, Scyliorhinus besnardi (Carcharhiniformes: Scyliorhinidae), off Brazil. Zootaxa 3352: 51-59. PDF
Taxon Coordinator:
Dr. Veronica A. Ivanov
Lab. Helmintologia
Departamento de Biodiversidad y Biologia Experimental
Facultad de Ciencias Exactas y Naturales
Universidad de Buenos Aires
Ciudad Universitaria, Pabellon II, piso 4, Lab. 52
C1428EHA Buenos Aires
Argentina
PHONE: 54-11-4576-3300 ext. 332
E-MAIL: ivanov@bg.fcen.uba.ar
Dr. Roman Kuchta
Institute of Parasitology
Academy of Sciences of the Czech Republic
Branisovská 31
370 05 Ceské Budejovice
Czech Republic
PHONE: ++420-38- 53-10-351
E-MAIL: krtek@paru.cas.cz
