title: Dollfustrema durum n. sp. and Heterobucephalopsis perardua n. sp. (Digenea: Bucephalidae) from the giant moray eel, Gymnothorax javanicus (Bleeker) (Anguilliformes: Muraenidae), and proposal of the Heterobucephalopsinae n. subfam.
abstract: Two new species of bucephalid trematode (Platyhelminthes: Digenea) are described from the giant moray eel, Gymnothorax javanicus (Anguilliformes: Muraenidae), from off Lizard Island, Australia. We used a combined morphological and molecular-based approach targeting the internal transcribed spacer 2 (ITS2) of the ribosomal DNA (rDNA) and the D1-D3 region of the large subunit (28S) of rDNA to circumscribe the species. Dollfustrema durum n. sp. is distinguished from seven congeners in having 5-6 rows of enlarged body spines circling the anterior portion of the rhynchus. From the remaining 10 species, D. durum n. sp. differs in body length, and in having a caecum that terminates posteriorly to the confluent arc formed by the vitelline follicles, gonads predominantly anterior to the pharynx, testes in tandem, an anterior testis positioned posteriorly to the vitelline follicles, and the pre-vitelline field 23-40% of the body length. Heterobucephalopsis perardua n. sp. differs from Heterobucephalopsis gymnothoracis, the type- and only other reported species, in being two to three times smaller. Heterobucephalopsis, currently considered a genus inquirendum, is confirmed as valid and is rediagnosed. Bayesian inference analysis of 28S rDNA sequences representing 28 species from nine genera and four subfamilies of bucephalid, indicates that i) subfamily classifications previously based on morphological characters are broadly robust, ii) the sequence representing H. perardua n. sp. is resolved as distinct, and basal, to sequences representing the Bucephalinae, the Prosorhynchinae, the Paurorhynchinae, and the Dolichoenterinae, iii) the Dolichoenterinae and the Prosorhynchinae are monophyletic sister clades, basal to the Bucephalinae and the Paurorhynchinae, iv) sequences representing Grammatorcynicola, Prosorhynchus, and Dollfustrema are also monophyletic, v) the Bucephalinae is paraphyletic relative to the Paurorhynchinae, and vi) the bucephaline genera Prosorhynchoides, Rhipidocotyle, and Bucephalus are each polyphyletic. The morphological and molecular differences observed among the four previously recognised subfamilies in this study lead us to propose Heterobucephalopsinae n. subfam. to accommodate the genus Heterobucephalopsis.
authors.affiliation: Department of Pathology and Pathogen Biology, Royal Veterinary College, University of London, North Mymms, Hatfield AL9 7TA, United Kingdom. Electronic address: mnolan@rvc.ac.uk.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Nolan
authors.affiliation: Gulf Coast Research Laboratory, The University of Southern Mississippi, East Beach Drive, Ocean Springs, MS 39564, USA. Electronic address: stephen.curran@usm.edu.
authors.forename: Stephen S
authors.initials: SS
authors.lastname: Curran
authors.affiliation: Fish Health Laboratory, Department of Fisheries, 3 Baron-Hay Court, South Perth, Western Australia 6151, Australia. Electronic address: Terry.Miller@agric.wa.gov.au.
authors.forename: Terrence L
authors.initials: TL
authors.lastname: Miller
authors.affiliation: School of Biological Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia. Electronic address: scott.cutmore@uqconnect.edu.au.
authors.forename: Scott C
authors.initials: SC
authors.lastname: Cutmore
authors.affiliation: Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, United Kingdom. Electronic address: cc779@cam.ac.uk.
authors.forename: Cinzia
authors.initials: C
authors.lastname: Cantacessi
authors.affiliation: School of Biological Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia. Electronic address: T.Cribb@uq.edu.au.
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Cribb
mesh_terms: D000818:Animals; D001315:Australia; D018509:DNA, Helminth / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D004524:Eels / Q000469:parasitology*; D005393:Fish Diseases / Q000469:parasitology*; D010802:Phylogeny; D012339:RNA, Ribosomal, 28S / Q000235:genetics; D014200:Trematoda / Q000033:anatomy & histology / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D014201:Trematode Infections / Q000469:parasitology*
chemical_list: D018509:DNA, Helminth; D021903:DNA, Ribosomal Spacer; D012339:RNA, Ribosomal, 28S
keywords: Internal transcribed spacer 2 (ITS2) of the ribosomal DNA (rDNA); Large subunit of rDNA (28S); Platyhelminthes; Trematoda