Redescriptions of two echinostomes from birds in Paraguay,with comments on Drepanocephalus Dietz, 1909 and Paryphostomum Dietz, 1909 (Digenea: Echinostomatidae)

Two species of echinostomatid trematodes from Paraguayan birds are redescribed: these are Drepanocephalus spathans Dietz, 1909 from Phalacrocorax olivaceus and Paryphostomum segregatum Dietz, 1909 from Coragyps atratus. The genera Drepanocephalus Dietz, 1909 and Paryphostomum Dietz, 1909 are redefined and the species previously assigned to them reviewed. Paryphostomum mexicanum (Lamothe-Argumedo &; Pérez-Ponce de León, 1989) n. comb. and P. parvicephalum (Rietschel &; Werding, 1978) n. comb. are transferred from Drepanocephalus to Paryphostomum. A key to the species of Paryphostomum is presented, and the nominal species of Echinostoma Rudolphi, 1809, Nephrostomum Dietz, 1909 and Artyfechinostomum Lane, 1915 previously ascribed to this genus are commented upon. New combinations for species previously attributed to Paryphostomum are: Echinostoma pentalobum (Verma, 1936) n. comb.; E. baiyangdienense (Ku, Pan, Chiu, Li &; Chu, 1973) n. comb.; Nephrostomum dollfusi (Agarwal, 1959) n. comb.; and Artyfechinostomum neotoma (Jain, 1953) n. comb. Species attributed to Paryphostomum which are here considered species inquirendae are: Paryphostomum (Lepustomum) mehrii Jain, 1953 sp. inq.; P. fragosum (Dietz, 1909) sp. inq.; P. horai Baugh, 1950 sp. inq.; P. huaccaci Ibáñez, 1974 sp. inq.; P. agrawali Gupta &; Singh, 1986 sp. inq.; P. siddiqui Gupta &; Singh, 1986 sp. inq.; P. durgensis Sapre, 1969 sp. inq.; and P. globorchum Oshmarin, 1970 sp. inq.     

Urotrematidae Poche, 1926 (Platyhelminthes: Digenea) in Chinese freshwater fishes

The genera Sinineobucephalopsis and Sinogastromyzontrema are diagnosed and placed in the family Urotrematidae. Sinineobucephalopsis macrocirrus is redescribed from Glyptothorax fokiensis in Guangdong and Hunan provinces. Urotrema glyptothoraci is considered synonymous with Sinineobucephalopsis macrocirrus. The new combinations Sinineobucephalopsis postlecitha, Sinineobucephalopsis proeilecitha and Sinineobucephalopsis sinipercae are formed for species originally placed in Urotrema and Urotrematulum. Sinogastromyzontrema guangxiensis is redescribed from Sinogastromyzon wui in Guangxi Province. Urotrema parallelorchis is considered a synonym of Sinogastromyzontrema guangxiensis. A key to the species or species-complexes in the family Urotrematidae is given.     

Three species of Pycnadenoides Yamaguti, 1938 (Digenea: Opecoelidae), including two new species from temperate marine fishes of Australia

Pycnadenoides pagrosomi Yamaguti, 1938 and P. reversati n. sp. from Pagrus auratus (Sparidae) and P. invenustus n. sp. from Nemadactylus valenciennesi (Cheilodactylidae) are described from the temperate marine waters off south-west Western Australia and south-east Queensland. The difference in the anterior extent of the vitelline follicles observed in P. reversati n. sp. recovered from off south-east Queensland waters and the material from off Western Australia is discussed. P. reversati n. sp. is distinguished from P. pagrosomi mainly in the position of the genital pore and in the arrangement of the testes, and from P. invenustus n. sp. in the posterior extent of the cirrus-sac. P. reversati belongs to the group of species with a short cirrus-sac and P. invenustus to the group with the cirrus-sac reaching into the anterior hindbody.     

Species of Trifoliovarium Yamaguti, 1940 (Digenea: Lecithasteridae) from Australian waters,with a description of T. draconis n. sp. and a cladistic study of the subfamily Trifoliovariinae Yamaguti, 1958

Three species of Trifoliovarium are described from marine fishes from Moreton Bay, Queensland: T. triacanthi (Parukhin, 1964) n. comb. (syns Hysterolecitha triacanthi Parukhin, 1964; T. triacanthi Bilqees, 1973; T. triacanthusi Gupta & Ahmad, 1976) from Tripodichthys angustifrons; T. ovarilobulus (Wang, 1989) n. comb. (syn. Hysterolecithia [sic] ovarilobuls) from Paramonacanthus japonicus and Pelates quadrilineatus: and T. draconis n. sp. from Callionymus sublaevis and C. belcheri. A list of the species of the subfamily Trifoliovariinae is given along with a key. A cladistic study of the subfamily based on 23 characters is presented, the results of which indicate the monophyly of the genus Assitrema and the paraphyly of Trifoliovarium.     

The subfamily Aephnidiogeninae Yamaguti, 1934 (Digenea: Lepocreadiidae), its status and that of the genera Aephnidiogenes Nicoll, 1915, Holorchis Stossich, 1901, Austroholorchis n. g., Pseudaephnidiogenes Yamaguti, 1971, Pseudoholorchis Yamaguti, 1958 and Neolepocreadium Thomas, 1960

The status of all of the putative member genera of the subfamily Aephnidiogeninae is reconsidered, based mainly on the morphology of the terminal genitalia. Aephnidiogenes Nicoll, 1915 is the only genus retained in the Aephnidiogeninae. Aephnidiogenes major Yamaguti, 1934 from Diagramma labiosum from the southern Great Barrier Reef is redescribed with particular reference to the terminal genitalia, and is shown to lack a true cirrus-sac, a condition considered to be diagnostic of the Aephnidiogeninae. Holorchis Stossich, 1901 is placed in the subfamily Lepidapedinae. Holorchis pycnoporus Stossich, 1901 from Pagellus acarne from off Spanish Sahara and from Diplodus vulgaris from off Italy and H. legendrei Dollfus, 1946 from Sparodon durbanensis and D. sargus from off eastern Cape Province, South Africa and from Pagellus erythrinus from the Adriatic Sea and Italy are studied and illustrated. The terminal genitalia of H. pycnoporus are found to be enigmatic, but those of H. legendrei are found to fit clearly into the 'Lepidapedon-like' pattern. A new genus Austroholorchis is erected in the Lepidapedinae, with A.sprenti (Gibson, 1987) n. comb. as the type-species. Its diagnostic features are its ani, infundibuliform oral sucker and the position of the ovary at about mid-level of the uterus . A. sprenti is illustrated, its hosts in Queensland waters being Sillago maculata, S. analis and S. ciliata. A. levis n. sp. is described from Sillago bassensis from south-western Western Australia. The genus PseudaephnidiogenesYamaguti, 1971 is placed in the Lepidapedinae. P. rhabdosargi (Prudhoe, 1956) from Rhabdosargus sarba from off Natal, South Africa is illustrated and the terminal genitalia of P. rhabdosargi from R. sarba and from R. holubi from off eastern Cape Province and Pseudaephnidiogenes rossi Bray, 1985 from Caffrogobius nudiceps from off eastern Cape Province, South Africa are illustrated. The genus Pseudoholorchis Yamaguti, 1958 is placed in the subfamily Lepocreadiinae. The terminal genitalia of P. pulcher (Manter, 1954) from Latridopsis ciliaris from New Zealand are illustrated. The genus Neolepocreadium Thomas, 1960 is placed in the Lepocreadiidae.     

A phylogenetic study of Lepidapedoides Yamaguti, 1970 (Digenea) with a key and descriptions of two new species from Western Australia

Two new species of the genus Lepidapedoides are described from the aulopodid teleost Aulopus purpurissatus from south-western Australia. Both are distinguished from other Lepidapedoides spp. by their pedunculate ventral sucker. Lepidapedoides pistoris n. sp. and L. elongatrium n. sp. are distinguished by the possession of a narrow, elongate form, a long ventral sucker to ovary distance, the vitellarium reaching only to the posterior level of the cirrus-sac, the cirrus-sac length and the deep genital atrium with the metraterm entering distally to its base in L. elongatrium. A key to species of the genus is given. A character matrix is included for the genus. Poorly resolved phylogenetic trees indicate two main lineages in the genus. The two new species described here are resolved as sister taxa. The new combination Lepidapedoides freitasi (Kohn &; Fernandes, 1970) is formed for Acanthocolpoides freitasi.     

Four species of Lepidapedoides Yamaguti, 1970 (Digenea: Lepocreadiidae) from fishes of the southern Great Barrier Reef, with a tabulation of host-parasite data on the group

Four species of the genus Lepidapedoides Yamaguti, 1970 are described from Heron Island, southern Great Barrier Reef, Queensland, Australia. They are: Lepidapedoides angustus n. sp. in Epinephelus fasciatus (type-host), E. cyanopodus, E. merra, E. quoyanus, E. ongus, Cephalopholis miniata and Diploprion bifasciatum; L. dollfusi (Durio & Manter, 1968) n. comb. [originally Neolepidapedon] in Epinephelus cyanopodus; L. ovale (Yamaguti, 1942) n. comb. [originally Pseudocreadium] in Caesio cuning and Pterocaesio marri; and L. parvulus n. sp. in Pterocaesio marri (type-host) and Caesio cuning. Host and distribution information on the species of the genus are tabulated according to morphological group. Mycterobonacinus Nasir & Gomez, 1977 is considered synonymous with Lepidapedoides, and M. magnifus is considered a synonym of L. nicolli.     

Complete Mitochondrial Genome of Echinostoma hortense (Digenea: Echinostomatidae)

Echinostoma hortense (Digenea: Echinostomatidae) is one of the intestinal flukes with medical importance in humans. However, the mitochondrial (mt) genome of this fluke has not been known yet. The present study has determined the complete mt genome sequences of E. hortense and assessed the phylogenetic relationships with other digenean species for which the complete mt genome sequences are available in GenBank using concatenated amino acid sequences inferred from 12 protein-coding genes. The mt genome of E. hortense contained 12 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and 1 non-coding region. The length of the mt genome of E. hortense was 14,994 bp, which was somewhat smaller than those of other trematode species. Phylogenetic analyses based on concatenated nucleotide sequence datasets for all 12 protein-coding genes using maximum parsimony (MP) method showed that E. hortense and Hypoderaeum conoideum gathered together, and they were closer to each other than to Fasciolidae and other echinostomatid trematodes. The availability of the complete mt genome sequences of E. hortense provides important genetic markers for diagnostics, population genetics, and evolutionary studies of digeneans.     

Phylogeny, evolution and biogeography of the Quadrifoliovariinae Yamaguti, 1965 (Digenea: Lecithasteridae)

The Quadrifoliovariinae is revised and three new species of Quadrifoliovarium Yamaguit, 1965 from acanthurid fishes of the genus Naso from waters of the Indo-Pacific are described: Q, maceria n. sp. from N.␣tonganus, N. annulatus, N. fageni and N. brevirostris; Q. simplex n. sp. from N. tonganus and N.␣annulatus; and Q. quattuordecim n. sp. from N. tonganus. Amendments are made to the characterisation of the Quadrifoliovariinae, Quadrifoliovarium, Bilacinia Manter, 1969 and Unilacinia Manter, 1969 in light of observations on type and new material. A molecular phylogeny based on ITS2 and 28S regions of the ribosomal DNA is proposed. The phylogeny suggests that U. asymmetrica is the most basal taxon and Q.␣simplex n. sp. and Q. quattuordecim n. sp. the most derived. Evolution of morphological traits within the Quadrifoliovariinae are discussed in light of the molecular phylogeny. Molecular sequences of the ITS2 rDNA were identical between specimens of Q. pritchardae collected off Exmouth (Indian Ocean), Heron Island and Lizard Island (Western Pacific) and Moorea (far Eastern Indo-Pacific), indicating a broad Indo-Pacific distribution. All members of the subfamily are recorded only from the acanthurid genus Naso, with the exception of B. lobatum (Yamaguti, 1970), which has been recorded from a pomacanthid. The restricted host range of the group is discussed in the light of the phylogeny of the host genus Naso.     

A comparative study of cercarial chaetotaxy in two species of Petasiger Dietz, 1909 (Digenea: Echinostomatidae)

The chaetotaxy of two types of cercariae found in naturally infected Planorbis planorbis in a brackish water lake in Bulgaria is described. The comparison of the sensory patterns shows the distinct species status of the cercariae of P. grandivesicularis and Petasiger sp. The morphology of the cercaria of Petasiger sp. is described and compared with that of known large-tailed Petasiger cercariae from the Palaearctic. It is suggested that the unidentified species of cercaria is probably a larval stage of P. pungens.     

Convoluted history and confusing morphology: Molecular phylogenetic analysis of dicrocoeliids reveals true systematic position of the Anenterotrematidae Yamaguti, 1958 (Platyhelminthes,Digenea)

The Dicrocoeliidae is a highly diverse family of digeneans parasitic in amniotic tetrapods. Detailed molecular phylogenetic analysis of dicrocoeliids is lacking and only a few dicrocoeliids from mammals have been included in previous studies. Sequence data were previously absent for the Anenterotrematidae that shares several morphological characteristics with dicrocoeliids. We examined phylogenetic affinities of several newly sequenced (nuclear 28S rDNA) taxa of dicrocoeliids and anenterotrematids collected from small mammals in Ecuador, Panama, Peru, USA and Vietnam. Our analyses demonstrated that the two anenterotrematid genera (Anenterotrema, Apharyngotrema) belong to the Dicrocoeliidae, placing the Anenterotrematidae into synonymy with the Dicrocoeliidae. Molecular data combined with morphological examination of type and new specimens provided evidence that Parametadelphis and Apharyngotrema are junior synonyms of Metadelphis, with all Metadelphis species lacking a digestive system. Phylogenetic analysis demonstrates that reduction of the alimentary tract in Lutztrema and its loss in Anenterotrema and Metadelphis represent at least two independent evolutionary events. Genera Brachylecithum, Brachydistomum, and Lyperosomum proved to be non-monophyletic, each likely representing more than a single genus. Furthermore, phylogenetic analysis did not support monophyly of the two largest subfamilies of the Dicrocoeliidae (Dicrocoeliinae and Leipertrematinae) with the other two subfamilies not included in this study. Therefore, we propose to abandon the current subfamily division of the Dicrocoeliidae. Analysis of host associations indicates multiple host-switching events throughout evolution of dicrocoeliids. Lastly, analysis of dicrocoeliid geographic distribution revealed that nearly all major clades included taxa from more than a single zoogeographic realm with the exception of the clade Anenterotrema?+?Metadelphis, found only in the Neotropics.     

Scanning electron microscopy of adult Echinoparyphium recurvatum (Von Linstow, 1873) (Digenea: Echinostomatidae) from Britain

The surface topography of 15-day-old adult Echinoparyphium recurvatum (Von Linstow, 1873) sensu stricto, from an isolate of the parasite utilizing Lymnaea peregra as first intermediate host in southern England, is described and illustrated using scanning electron microscopy, and is compared to those of other Echinoparyphium species from Europe, and with those of E. recurvatum of East Asian origin. The general morphology of tegumental features was found to be very similar to that of worms of the same age observed in a previous study on a Korean isolate of E. recurvatum. Comparison of collar and body spination of E. recurvatum with other 45-collar-spined members of the genus in Europe revealed some significant differences in morphology. Collar spines of E. recurvatum were found to be shorter and more pointed than those of Echinoparyphium mordwilkoi. The body spines of E. recurvatum are rounded and scale-like, extending just beyond the ventral sucker, contrasting with the pointed, thorn-shaped body spines of E. mordwilkoi, extending posteriorly to the level of the second testis. Body spine shape and distribution in E. recurvatum were found to be more similar to those of Echinoparyphium pseudorecurvatum. The value of SEM studies in elucidating the relationship between members of the genus Echinoparyphium in Britain/Europe and those in Africa, Asia and North America is suggested.     

Reproduction of the trematode Echinostoma caproni parthenites (Digenea: Echinostomatidae)

Dynamics of the reproduction in the trematode Echinostoma caproni parthenites (Echinostomatidae) was observed. Early laying and maturation of the generative cells are for the first time shown to be characteristic for all parthenogenetic generations. Really the process of reproduction had been finishing to the beginning of the generating of new age by parthenites. Mother sporocysts, as well as redia of different generations, in fact stop producing new generative cells with the beginning of the generating of new age, and assume the function of a brood pouch. This feature was considered previously as peculiar mainly to mother sporocysts. Data on the autotomy of the anterior body end in mother sporocysts are verified. In our opinion, these data are an evidence of an early manifestation of the evolutionary trend to the morpho-functional regress and disintegration of the parasitic stage of mother sporocyst.     

Two new species of bucephalids (Digenea: Bucephalidae) parasitic in freshwater fishes of Argentina

Two new species of bucephalids (Digenea: Bucephalidae) were found parasitizing freshwater fishes of Argentina. Prosorhynchoides cambapuntaensis sp. n. from Salminus maxillosus (Characidae) is characterised by the tegument covered with two kinds of spines, scale-like spines anteriorly and fine spines posteriorly; uterine loops reaching the vitelline arch in the pre-oral region; and the Laurer's canal short, opening dorsally immediately posterior to the ovary. Rhipidocotyle santanaensis sp. n. from Acestrorhynchus pantaneiro (Acestrorhynchidae) is characterised by the rhynchus with two lateral projections; the testes arranged in tandem or slightly diagonal; and the vitelline follicles forming an arch in the pre-oral region.     

Lepocreadiidae Odhner, 1905 and Aephnidiogenidae Yamaguti, 1934 (Digenea: Lepocreadioidea) of fishes from Moreton Bay,Queensland, Australia,with the erection of a new family and genus

Digeneans of the lepocreadioid families Lepocreadiidae Odhner, 1905 and Aephnidiogenidae Yamaguti, 1934 from Moreton Bay, off southern Queensland, Australia, are recorded, along with the erection of a new family, Gibsonivermidae. Molecular data were generated for all representatives of these families collected during this study and a phylogram for members of the superfamily was generated based on the partial 28S rDNA dataset, placing these species in context with those previously sequenced. This phylogenetic analysis demonstrates that the monotypic Gibsonivermis Bray, Cribb & Barker, 1997 is isolated from all other lepocreadioids and supports the erection of Gibsonivermidae n. fam., which is defined morphologically, based particularly on the uniquely elongated male terminal genitalia, the distribution of the uterus in the forebody and the presence of a uroproct. Mobahincia teirae n. g., n. sp. is reported from Platax teira (Forsskål) in Moreton Bay and off Heron Island and New Caledonia. Recognition of this new genus is based on molecular results and the combination of caeca abutting the posterior body wall and the lack of an anterior body scoop or flanges. The following lepocreadioid species are reported from Moreton Bay for the first time: Bianium arabicum Sey, 1996 in Lagocephalus lunaris (Bloch & Schneider), Diploproctodaeum cf. monstrosum Bray, Cribb & Justine, 2010 in Arothron hispidus (Linnaeus), Multitestis magnacetabulum Mamaev, 1970 and Neomultitestis aspidogastriformis Bray & Cribb, 2003 in Platax teira and Opechona austrobacillaris Bray & Cribb, 1998 in Pomatomus saltatrix (Linnaeus). Bianium plicitum (Linton, 1928) is reported from Torquigener squamicauda (Ogilby) for the first time. Sequences of newly collected specimens of Austroholorchis sprenti (Gibson, 1987) indicate that the species forms a clade with other members of the Aephnidiogenidae, agreeing with its morphology. The phylogenetic status of all newly sequenced species is discussed.     

A discussion of the status of the subfamily Baccigerinae Yamaguti, 1958 (Digenea) and the constitution of the family Fellodistomidae Nicoll, 1909

Contrary to recent reports it is suggested that the subfamily Baccigerinae belongs in the monophyletic family Fellodistomidae and is not closely related to the Lepocreadiidae. This conclusion is based on both morphological and life-history information. The Fellodistomidae contains seven subfamilies: Fellodistominae, Baccigerinae, Lintoniinae, Monascinae, Monodhelminthinae, Proctoecinae and Tergestiinae. Their relationships are discussed. In these groups, at least, the cercarial tail should only be usedas a phylogenetic indicator with great caution.     

Surface ultrastructure of juvenile and adult Acanthoparyphium tyosenense (Digenea: Echinostomatidae)

The tegumental ultrastructure of juvenile and adult Acanthoparyphium tyosenense (Digenea: Echinostomatidae) was observed by scanning electron microscopy. One- to 3-day-old juveniles and 10-day-old adults were harvested from chicks experimentally fed metacercariae from a bivalve, Mactra veneriformis. The juvenile worms were minute, curved ventrally, and had 23 collar spines characteristically arranged in a single row. The lips of the oral sucker had 7 single aciliated sensory papillae and 4 grouped uniciliated sensory papillae. The ventral sucker had 25 aciliated round swellings on its lip. The anterolateral surface between the 2 suckers was densely packed with tongue-shaped tegumental spines, and the ventral surface just posterior to the ventral sucker was covered with peg-like spines. Retractile, peg-like spines were seen on the anterolateral surface, whereas scale-like spines with round tips and broad bases were sparsely distributed posterior to the ventral sucker. The cirrus was characteristically protruding and armed with minute spines. The surface ultrastructure of A. tyosenense was unique, especially in the number and arrangement of collar spines, shape, and distribution of tegumental spines and in distribution of sensory papillae.     

Life cycle of Stephanoprora uruguayense (Digenea: Echinostomatidae) in Argentina

The life cycle of Stephanoprora uruguayense Holcman et Olagüe, 1989, was experimentally resolved. In an artificial pond in the Zoological Garden in Buenos Aires City, Argentina, Heleobia parchappei (Hydrobiidae) was found to be releasing large-tailed cercariae with a prepharyngeal body, but lacking collar spines and corpuscles in the excretory system. Metacercariae, which encysted on the gills of naturally and experimentally infected Cnesterodon decemmaculatus (Poecilidae), developed collar spines and corpuscles in the excretory system in 7 days. Sexually mature adults were recovered from chicks and immature adults from mice fed metacercariae from C. decemmaculatus. Eggs shed in chick feces developed to miracidia within 10 days; sporocysts were found on the gills of snails. Stephanoprora uruguayense and S. denticulata from Europe are similar in adult morphology, but can be distinguished by morphological and behavioral features of larvae. Likewise, although S. denticulata and S. paradenticulata from Venezuela are similar to S. uruguayense in adult morphology, they differ considerably in larval morphology and intermediate hosts.