Jumping continents and major host lineages: phylogeny and diversity of the enigmatic Cryptotropidae (Platyhelminthes: Digenea).

Members of several genera in the digenean superfamily Microphalloidea, namely Renschetrema, Rohdetrema, Cryptotropa, Cephalouterina and Pseudocryptotropa, are characterized by an unusual dorsal position of the genital atrium. In the absence of phylogenetic data, their systematic position has been unstable. In the most recent taxonomic revision of the Microphalloidea, they were housed in three different families. We studied the morphology and obtained DNA sequences of several microphallolideans with a dorsal genital pore, collected from vertebrates in Southeast Asia and South America. We used sequences of the nuclear 28S gene to infer a superfamily-level phylogeny and sequences of the mitochondrial cox1 gene for family-level phylogeny and species-level comparisons. Based on the combination of molecular phylogenetic data and morphological features, we restore the Cryptotropidae and synonymize the Renschetrematidae with the Cryptotropidae. We erect new genera Paracryptotropagen. nov. and Armadoatriumgen. nov., provide amended diagnoses of the Cryptotropidae and Renschetrema and provide keys to the identification of genera within the family. We resurrect the genus Novetrema, previously synonymized with Pseudocryptotropa, and remove Renschetrema indicum from Renschetrema. We describe four new species from lizards in Vietnam and birds in the Philippines and Peru. The unique morphological features and unusually broad host associations and geographical distributions of cryptotropids are discussed.

Molecular phylogeny supports invalidation of Didelphodiplostomum and Pharyngostomoides (Digenea: Diplostomidae) and reveals a Tylodelphys from mammals.

Alaria, Didelphodiplostomum and Pharyngostomoides are among genera of diplostomid digeneans known to parasitize mammalian definitive hosts. Despite numerous recent molecular phylogenetic studies of diplostomids, limited DNA sequence data is available from diplostomids parasitic in mammals. Herein, we provide the first 28S rDNA and cox1 mtDNA sequences from morphologically identified, adult specimens of Didelphodiplostomum and Pharyngostomoides. Newly generated 28S sequences were used to infer the phylogenetic interrelationships of these two genera among other major lineages of diplostomoideans. The phylogeny based on 28S and a review of morphology clearly suggests that Pharyngostomoides should be considered a junior synonym of Alaria, while Didelphodiplostomum should be considered a junior synonym of Tylodelphys. Pharyngostomoides procyonis (type species), Pharyngostomoides adenocephala and Pharyngostomoides dasyuri were transferred into Alaria as Alaria procyonis comb. nov., Alaria adenocephala comb. nov. and Alaria dasyuri comb. nov.; Didelphodiplostomum variabile (type species) and Didelphodiplostomum nunezae were transferred into Tylodelphys as Tylodelphys variabilis comb. nov. and Tylodelphys nunezae comb. nov. In addition, Alaria ovalis comb. nov. (formerly included in Pharyngostomoides) was restored and transferred into Alaria based on a morphological study of well-fixed, adult specimens and the comparison of cox1 DNA sequences among Alaria spp. The diplostomid genus Parallelorchis was restored based on review of morphology.

Phylogenetic relationships of the Renschetrematidae Yamaguti, 1971 with description of a new species of Renschetrema Rohde, 1964 from the Philippines.

Renschetrematidae is a very small family of digeneans parasitic in bats in southern and Southeast Asia. According to the original descriptions and the latest revision, its representatives are characterized by the presence of several unusual characters. Among them are the dorsal position of the genital pores, separate male and female genital pores, and the presence of an accessory sac (stylet pouch) associated with terminal genitalia and containing a stylet-like structure. Prior to our study, the phylogenetic relationships of the Renschetrematidae were unknown and DNA sequence data were absent from any of its representatives. In this work, we present the description of a new species of Renschetrema from bats in the Philippines. We also evaluate the phylogenetic affinities of the Renschetrematidae using newly obtained partial sequences of the 28S rRNA gene from Renschetrema specimens collected in the Philippines and Southeast China. The new species differs from previously described species by the position and orientations of the stylet pouch, presence of accessory spines around genital atrium, position of gonads, body shape and relative size of pharynx and oral sucker. Our phylogenetic analysis supports the status of the Renschetrematidae as an independent family within the superfamily Microphalloidea. In the phylogenetic tree, the Renschetrematidae appeared as an independent family-level lineage, basal to the remaining taxa within the Microphalloidea. Detailed examination of our specimens revealed significant errors in the current diagnoses of the genus Renschetrema and the Renschetrematidae. Amended diagnoses of the genus and the family are provided.

Integration of morphological and molecular data reveals further unknown diversity of the Proterodiplostomidae in crocodilians.

The Proterodiplostomidae Dubois, 1936 is a family of digeneans within the superfamily Diplostomoidea Poirier, 1886. Members of the family are distributed mostly in the tropics and subtropics, primarily in crocodilians, although some species are known from other reptiles. Despite their broad geographical distribution, the knowledge of proterodiplostomid diversity remains limited, mostly because a number of potential host species and regions of the world have not been sufficiently explored for these parasites. In this study, we use morphological and molecular data to describe four new genera (Afroproterodiplostomum gen. nov., Dungalabatrema gen. nov., Australiadiplostomum gen. nov. and Nattererodiplostomum gen. nov.) and five new species (Afroproterodiplostomum ingwenyae sp. nov., Australiadiplostomum blairi sp. nov., Dungalabatrema kostadinovae sp. nov., Dungalabatrema snyderi sp. nov. and Pseudoneodiplostomum angustus sp. nov.) of proterodiplostomids from crocodilians in Australia, South Africa and South America. Nattererodiplostomum gen. nov. has been established upon re-evaluation of the status of Proterodiplostomum medusae (Dubois, 1936) from caimans in Brazil using combined morphological and molecular evidence. Only a few previous studies provided DNA sequence data of proterodiplostomids. We generated partial 28S rDNA and cytochrome c subunit (cox1) mtDNA for three previously undescribed proterodiplostomids collected from Crocodylus spp. in Australia and South Africa. The newly generated 28S sequences were used to examine phylogenetic affinities of these taxa. All three newly sequenced proterodiplostomid species appeared in the phylogenetic tree in a strongly supported monophyletic clade comprising exclusively parasites of Crocodylus.

Unravelling the diversity of the Crassiphialinae (Digenea: Diplostomidae) with molecular phylogeny and descriptions of five new species.

Crassiphialinae Sudarikov, 1960 is a large subfamily of the Diplostomidae Poirier, 1886 with a complex taxonomic history. It includes a diversity of species parasitic in the intestines of avian and mammalian definitive hosts worldwide. Posthodiplostomum Dubois, 1936 is a large and broadly distributed crassiphialine genus notorious for its association with diseases in their fish second intermediate hosts. In this study, we generated partial 28S rDNA and cytochrome c oxidase subunit 1 (cox1) mtDNA gene sequences of digeneans belonging to seven crassiphialine genera. The 28S sequences were used to study the interrelationships among crassiphialines and their placement among other major diplostomoidean lineages. Our molecular phylogenetic analysis and review of morphology does not support subfamilies currently recognized in the Diplostomidae; therefore, we abandon the current subfamily system of the Diplostomidae. Molecular phylogenetic analyses suggest the synonymy of Posthodiplostomum, Ornithodiplostomum Dubois, 1936 and Mesoophorodiplostomum Dubois, 1936; morphological study of our well-fixed adult specimens and review of literature revealed lack of consistent differences among the three genera. Thus, we synonymize Ornithodiplostomum and Mesoophorodiplostomum with Posthodiplostomum. Our phylogenetic analyses suggest an Old World origin of Posthodiplostomum followed by multiple dispersal events among biogeographic realms. Furthermore, our analyses indicate that the ancestors of these digeneans likely parasitized ardeid definitive hosts. Four new species of Posthodiplostomum collected from birds in the New World as well as one new species of Posthodiplostomoides Williams, 1969 from Uganda are described.