Diagnosis. Scolex with 4 bothridia; bothridia with, or occasionally without, facial loculi; apical sucker and conspicuous anterior/posterior orientation of bothridia lacking; myzorhynchus present in adult stage. Postvaginal testes usually lacking. Vitelline follicles not interrupted by ovary. Parasites of Rajiformes (sensu Naylor et al. 2012 a).
Type genus: Echeneibothrium van Beneden, 1850. Additional genera: Clydonobothrium Euzet, 1959, Notomegarhynchus Ivanov & Campbell, 2002, Phormobothrium Alexander, 1963, Pseudanthobothrium Baer, 1956, Tritaphros Lönnberg, 1889.
Remarks. Echeneibothriidae was originally established as a family-group name by de Beauchamp (1905) who recognized it as a tribe in the family “Phyllobothridés” [sic, pg. 499] and in essence characterized it as having “bothridies allongées, subdivisées par des crêtes musculaires en areoles quadrangulaires qui les ont fait comparer au disque céphalique du Remora, jamais de ventouse acessoire, myzorhynchus parfois très développé.” It was formally treated as a family by Riser (1955; pg. 281) who characterized it as follows: “Phyllidia pedicellate, elongate, oval, with bothridial surface muscular and divided by temporary ridges into loculi.” Euzet (1994) expanded the diagnosis to include the absence of postvaginal testes, and also to include genera such as Pseudanthobothrium, which lack facial loculi, but he considered the Echeneibothriinae as a subfamily of the Tetraphyllidea. The diagnosis presented here follows Euzet (1994). The persistence of a myzorhynchus in the adult stage distinguishes this family from the other three families in the order.