Revision of the Grillotia erinaceus (van Beneden, 1858) species complex (Cestoda: Trypanorhyncha), with the description of G. brayi n. sp.

Members of the trypanorhynch cestode genus Grillotia Guiart, 1927 belonging to the Grillotia erinaceus (van Beneden, 1858) species complex are redescribed. The type-species of the genus, G. erinaceus, is redescribed from Raja spp. in the eastern and western north Atlantic and the Mediterranean. The redescription establishes the presence of: an hermaphroditic sac; internal and external seminal vesicles (but absence of an accessory seminal vesicle); a uterine pore; and the attachment of the retractor muscle in the mid-region of the tentacular bulb. G. pseuderinaceus Dollfus, 1969 and G. recurvispinis Dollfus, 1969 from Raja spp. in the Mediterranean are considered to be synonyms of G. erinaceus, following Palm (2004). G. dollfusi Carvajal, 1971 from R. chilensis Guichenot off Chile is redescribed from the paratypes and features of the terminal genitalia, consistent with those of G. erinaceus, are described for the first time. G. musculara (Hart, 1936) is redescribed from new material collected from the type-host, R. rhina (Jordan & Gilbert), off Nanaimo on the western coast of Canada. The features of the terminal genitalia of G. musculara are similar to those of the G. erinaceus group. The morphological features of G. borealis Keeney & Campbell, 2001 from Bathyraja spp. in the Bering Sea and the Sea of Okhotsk are summarised and illustrations of this species provided. G. brayi n. sp. is described from Amblyraja radiata from the coasts of Iceland and Britain. The new species differs from other members of the complex in lacking modified hooks 1 and 1' at the base of the tentacle (differentiating it from G. erinaceus), a long pars vaginalis (differentiating it from G. dollfusi) and uncinate hooks in the band on the external surface of the tentacle (differentiating it from G. musculara). Brief descriptions are provided of two apparently new species of Grillotia currently represented in collections by single specimens.