Review of the Rhopalothylacidae Guiart , 1935 ( Cestoda : Trypanorhyncha ) , with a description of the adult

The family Rhopalothylacidae (Cestoda: Trypanorhyncha) is reviewed. The type species, Rhopalothylax gymnorhynchoides Guiart, 1935, is redescribed from the type specimens and belongs within the genus Pintneriella Yamaguti, 1934, previously described only from the plerocercus. Rhopalothylax therefore becomes a junior synonym of Pintneriella. The adult of Pintneriella musculicola Yamaguti, 1934 is described for the first time, from the shark Carcharias taurus Rafinesque from Australia. Pintneriella is characterised by two bothridia, a typical heteroacanthous armature, a unique, bipartite external seminal vesicle and a uterus deviated porally, terminating at a uterine pore. It belongs within the Heteracanthoidea but is distinguishable both from the Eutetrarhynchidae and the Gilquiniidae, the two families which it most closely resembles. Cladistic analyses align Pintneriella within the clade containing the families Gilquiniidae, Gymnorhynchidae and Molicolidae rather than with the Eutetrarhynchidae. The family Rhopalothylacidae is therefore retained provisionally to accommodate Pintneriella within the Heteracanthoidea. The second genus of the Rhopalothylacidae, Clujia Guiart, 1935, is unrecognisable from its description and cannot be redescribed from its holotype. It is therefore considered a genus inquirendum. The trypanorhynch cestode family Rhopalothylacidae was erected by Guiart (1935) to accommodate two new genera, Rhopalothylax and Clujia, which he described from plerocerci collected from fishes in the Atlantic Ocean (Guiart 1935). The descriptions of both genera are poor with no details of the tentacular armature, such that Dollfus (1942, p. 426) was unable to place either the genera or the family within the classification he developed. Yamaguti (1959), Schmidt (1986) and Campbell and Beveridge (1994) subsequently treated the family and both of its constituent genera as incertae sedis. In this paper, the type specimens of both of the type species, Rhopalothylax gymnorhynchoides Guiart, 1935 and Clujia racovitzai Guiart, 1935 were re-examined to determine whether or not their taxonomic positions could be determined. The holotype of Clujia proved to be in poor condition and its taxonomic position could not be determined. However, the type material of Rhopalothylax gymnorhynchoides proved to be similar to but distinct from Pintneriella musculicola Yamaguti, 1934, recently redescribed from plerocerci by Beveridge and Campbell (2000). The adult of P. musculicola is described here for the first time from an Australian shark; R. gymnorhynchoides is redescribed. The detailed descriptions of two species of Pintneriella allow further investigation of the taxonomic position of the genus, which was considered a genus incertae sedis by Beveridge and Campbell (2000). In addition, the validity and taxonomic position of the Rhopalothylacidae is evaluated. MATERIALS AND METHODS Type specimens of Clujia racovitzai Guiart, 1935 and Rhopalothylax gymnorhynchoides Guiart, 1935 were borrowed from the Musée Océanographique de Monaco (MOP). Paratype and additional material of Pintneriella musculicola Yamaguti, 1934 from the Meguro Parasitological Museum, Tokyo (MPO) have previously been examined by the authors (Beveridge and Campbell 2000). Adult specimens of P. musculicola were collected from the spiral valve of a captive grey nurse shark, Carcharias taurus Rafinesque, which died following transportation from the Mooloolaba Aquarium in Queensland, Australia, to the Melbourne Aquarium. Although born in captivity, the shark had been fed on fish collected in the Mooloolaba region. Cestodes collected were relaxed briefly in tap water and fixed in AFA solution (Pritchard and Kruse 1982). Cestodes were stained in Celestine blue, dehydrated in ethanol, cleared in methyl salicylate and mounted in Canada balsam. Tentacles were removed from individual scoleces using a scalpel blade, mounted in glycerine jelly and manipulated until appropriate FOLIA PARASITOLOGICA 50: 61–71, 2003 Address for correspondence: I. Beveridge, University of Melbourne, Department of Veterinary Science, 250 Princes Highway, Werribee, Victoria 3030, Australia. Phone: ++61 3 9731 2285; Fax: ++61 3 9731 2203; E-mail: [email protected]