Redescriptions of species of Tetrarhynchobothrium Diesing, 1850 and Didymorhynchus Beveridge & Campbell, 1988 (Cestoda: Trypanorhyncha), with the description of Zygorhynchus borneensis n. sp

Tetrarhynchobothrium tenuicolle Diesing, 1850 is redescribed from the type-specimens collected from Raja clavata Linnaeus in the Adriatic Sea. T. striatum (Wagener, 1854) is redescribed from voucher specimens from the type host, Myliobatis aquila Linnaeus, from the type-locality, off Naples, Italy. The two species are very similar in tentacular armature, but are provisionally maintained as independent species, since the armature of T. tenuicolle cannot be fully described and because all available specimens of T. striatum are immature, limiting comparisons of potential differences in segment anatomy. T. setiense Dollfus, 1969 is treated as a synonym of T. striatum. Zygorhynchus borneensis n. sp. is described from Himantura uarnacoides (Bleeker) and H. pastinacoides (Bleeker) off Sabah, Malaysia. The new species is distinguished from its congeners by the very small hooks present in the basal region and by the presence of a uterine pore. The metabasal tentacular armature of Didymorhynchus southwelli Beveridge & Campbell, 1988, described for the first time, is homeoacanthous and homeomorphous in form. However, it has a basal swelling with hook rows originating on the bothrial surface and terminating on the antibothrial surface of the tentacle.     

A new species of Dollfusiella Campbell & Beveridge, 1994 (Cestoda: Eutetrarhynchidae), with remarks on Halysiorhynchus macrocephalus (Shipley & Hornell, 1906) (Cestoda: Mixodigmatidae) from the bowmouth guitarfish Rhina ancylostoma Bloch & Schneider (Rhinidae) in the Persian Gulf

Systematic Parasitology - Dollfusiella nimai n. sp. (Cestoda: Eutetrarhynchidae) is described from the intestine of Rhina ancylostoma Bloch & Schneider in the Persian Gulf. The number of...     

Redescription of <Emphasis Type="Italic">Cetorhinicola acanthocapax</Emphasis> Beveridge &; Campbell, 1988 (Cestoda: Trypanorhyncha) from the Basking Shark <Emphasis Type="Italic">Cetorhinus maximus</Emphasis> (Gunnerus)

Cetorhinicola acanthocapax Beveridge & Campbell, 1988 is redescribed based on adult specimens collected from a basking shark Cetorhinus maximus (Gunnerus) off the east coast of New Zealand. Both the mature and gravid segments are described for the first time, and the first scanning electron micrographs of the armature and scolex microtriches are provided. Novel features include the opening of the vagina anterior to the cirrus-sac and the extension of the vagina anterior to the cirrus-sac. Pectinate microtriches are present on the anterior quarter of the pars pedunculus scolecis scattered between filiform microtriches; the bothrial margins are covered with tridigitate microtriches, while the adherent surface of the bothria have pectinate microtriches. The additional morphological features described are consistent with a close association between Cetorhinicola Beveridge & Campbell, 1988 and the Eutetrarhynchoidea Guiart, 1927.     

Two new species of Pseudochristianella Campbell & Beveridge, 1990 (Cestoda: Trypanorhyncha) from elasmobranch fishes from the Gulf of California, Mexico

Pseudochristionella elegantissima sp. nov. (Cestoda: Trypanorhyncha) is described from the spiral valves of the rays Dasyatis brevis (Garman, 1880) and D. longus (Garman, 1880), from the Gulf of California, Mexico. Also described is P. nudisculo sp. nov. from rays Rhinobatos productus Ayres, 1854, D. longus, Myliobatis longirostris Applegate & Fitch, 1964 and Zapteryx exasperat (Jordan & Gilbert, 1880) from the same location. The species are distinguished from one another and from the only existing species within the genus, P. southwelli Campbel & Beveridge, 1990, by differences in the arrangement of bill-hooks on the external surface of the basal swelling of the tentacle and by the number of hooks in each row of the metabasasl armature.