Intercontinental distributions, phylogenetic position and life cycles of species of Apharyngostrigea (Digenea, Diplostomoidea) illuminated with morphological, experimental, molecular and genomic data.

When subjected to molecular study, species of digeneans believed to be cosmopolitan are usually found to consist of complexes of species with narrower distributions. We present molecular and morphological evidence of transcontinental distributions in two species of Apharyngostrigea Ciurea, 1924, based on samples from Africa and the Americas. Sequences of cytochrome c oxidase I and, in some samples, internal transcribed spacer, revealed Apharyngostrigea pipientis (Faust, 1918) in Tanzania (first known African record), Argentina, Brazil, USA and Canada. Sequences from A. pipientis also match previously published sequences identified as Apharyngostrigea cornu (Zeder, 1800) originating in Mexico. Hosts of A. pipientis surveyed include definitive hosts from the Afrotropic, Neotropic and Nearctic, as well as first and second intermediate hosts from the Americas, including the type host and type region. In addition, metacercariae of A. pipientis were obtained from experimentally infected Poecilia reticulata, the first known record of this parasite in a non-amphibian second intermediate host. Variation in cytochrome c oxidase I haplotypes in A. pipientis is consistent with a long established, wide-ranging species with moderate genetic structure among Nearctic, Neotropic and Afrotropic regions. We attribute this to natural dispersal by birds and find no evidence of anthropogenic introductions of exotic host species. Sequences of CO1 and ITS from adult Apharyngostrigea simplex (Johnston, 1904) from Egretta thula in Argentina matched published data from cercariae from Biomphalaria straminea from Brazil and metacercariae from Cnesterodon decemmaculatus in Argentina, consistent with previous morphological and life-cycle studies reporting this parasite-originally described in Australia-in South America. Analyses of the mitochondrial genome and rDNA operon from A. pipientis support prior phylogenies based on shorter markers showing the Strigeidae Railliet, 1919 to be polyphyletic.

A new species of Cosmocercoides (Nematoda; Cosmocercidae) and other helminths in Leptodactylus latrans (Anura; Leptodactylidae) from Argentina.

Cosmocercoides latrans n. sp. (Cosmocercidae) from the small intestine of Leptodactylus latrans (Anura: Leptodactylidae) from Northeastern Province of Buenos Aires, Argentina is described. The new species can be distinguished from their congeners by a combination of the characters, among which stands out the number of rosette papillae, the lack of gubernaculum and the presence of lateral alae in both sexes. There are over 20 species in the genus Cosmocercoides, and Cosmocercoides latrans n. sp. represents the third species from the Neotropical realm and the second for Argentina. Additionally, seven previously known taxa are reported; Pseudoacanthocephalus cf. lutzi, Catadiscus uruguayensis, Rauschiella palmipedis, Aplectana hylambatis, Cosmocerca parva, Schrankiana sp. and Rhabdias elegans; providing literature records and information on distribution and host-parasite relationships.

Phylogenetic position of Diplostomum spp. from New World herons based on complete mitogenomes, rDNA operons, and DNA barcodes, including a new species with partially elucidated life cycle.

Diplostomum ardeae Dubois, 1969 has seldom been reported since its description from the great blue heron (Ardea herodias L., 1758) in the USA. Sequences obtained in this study from the barcode region of cytochrome c oxidase 1 (CO1) in diplostomids from black-crowned night heron (Nycticorax nycticorax (L., 1758)) in Puerto Rico matched data from D. ardeae from A. herodias in the type region. We also obtained DNA barcodes from morphologically similar diplostomids from a rufescent tiger heron (Tigrisoma lineatum (Boddaert, 1783)) and from metacercariae from eye lenses of Trachelyopterus galeatus (Linnaeus, 1766) from the Paraná River basin in Argentina and Brazil, respectively. Barcodes matched (97-100% identity) in these South American adult and larval specimens as well as in recently published sequences from metacercariae from 11 other siluriform fishes from the same region. Barcodes from the South American species, which we describe as Diplostomum lunaschiae n. sp., differed from those of D. ardeae by 7.2-9.8%, and the new species differs from D. ardeae in its size, pharynx:oral sucker length ratio, egg:body length ratio, and distribution of vitellaria. As in prior phylogenetic analysis of CO1 sequences, both D. ardeae and D. lunaschiae n. sp. were not associated with Diplostomum. In more character-rich analyses of nuclear rDNA and of mitochondrial genomes, D. ardeae was an early divergent member of clades of species of Diplostomum. Consequently, we continue to consider D. ardeae and D. lunaschiae n. sp. members of Diplostomum, in contrast to recent suggestions that these species may belong to a different genus.

Cestode Parasites of Armadillos (Mammalia: Xenarthra) from Argentina: Two New Species of Mathevotaenia (Anoplocephalidae) in Tolypeutes matacus.

A total of 20 specimens of Tolypeutes matacus (Desmarest, 1804) from the Chaco Region in Argentina were examined. This study revealed the presence of 3 species of the genus Mathevotaenia Akumyan, 1946 (Cestoda Anoplocephalidae), two of them new for science. These species are described, illustrated, and compared with related species. Mathevotaenia chamicalensis n. sp. is characterized by having a small body with 45-65 proglottids; a globose scolex, longer than wide and well delimited from strobila; a long neck; mature and gravid proglottids longer than wide; and 20-35 testes located in a single field. Mathevotaenia yepesi n. sp. is characterized by having a small body with 86-128 proglottids; a rectangular scolex, wider than long and not well delimited from strobila; neck absent; mature and gravid proglottids wider than long; and 23-50 testes located in the medial portion of the proglottid. The finding of Mathevotaenia argentinensis Campbell et al., 2003 parasitizing T. matacus represents the first record in armadillos.

A new species of Microtetrameres (Nematoda, Tetrameridae) parasitizing Buteogallus urubitinga (Aves, Accipitridae) from northeastern Argentina.

A new tetramerid nematode, Microtetrameres urubitinga n. sp., is described from specimens recovered from the proventriculus of the great black-hawk, Buteogallus urubitinga (Aves: Accipitridae), from Formosa Province, Argentina. The males of the new species are characterized by having spicules unequal (length ratio of spicules 1:3.8-5.9) and dissimilar in shape (right spicule with a simple tip, left spicule with a symmetrical bifurcated tip), caudal papillae arranged asymmetrically (two pairs precloacal and two pairs postcloacal) and cloacal lips highly protruded forming a tube. The gravid females are permanently coiled clockwise or counterclockwise in a spiral and having a tail tapering gradually to a sharp point, with a cuticular fold. This is the first nominal species of Microtetrameres (Travassos, 1915) described parasitizing birds from Argentina. The relationship between the diet of B. urubitinga and the low prevalence of M. urubitinga n. sp. is discussed.

Strigeid parasites of Circus buffoni from Argentina, with the description of a new species of Parastrigea Szidat, 1928.

Studying the Helminthological Collection of Museo de La Plata (MLP-He), several specimens of digeneans, recovered parasitizing a long-winged harrier, Circus buffoni (Accipitridae) from Buenos Aires Argentina, were analysed. The morphological and morphometric analysis of these specimens revealed the presence of two strigeid species, one of them new for science. Parastrigea buffoni n. sp. is characterised by a forebody differentiated in a retractile cephalic region with a large opening and a balloon-shaped collar region or collerette, suckers located in cephalic region, holdfast organ with well development dorsal and ventral lips that can emerge through opening, a claviform hindbody, a large copulatory bursa with muscular ring (Ringnapf) and a genital cone well delimited, crossed by a sinuous hermaphroditic duct with internal rugae. The euryxenous parasite, Strigea falconis brasiliana, is briefly described, parasitizing a new host. This is the first record of helminths parasitizing long-winged harrier.

Nematode parasites of the Chilean Flamingo, Phoenicopterus chilensis (Phoenicopteridae) from Central Argentina, with a description of a new species of Tetrameres (Tetrameridae).

During the summer of 2013, several specimens of Phoenicopterus chilensis (Phoenicopteridae) were found dead from unknown causes, in lakes from the endorheic system "Encadenadas del Oeste", Buenos Aires Province, Argentina. Two species of Nematoda were recovered from the proventriculus, one of them new for science. The tetramerid Tetrameres (Tetrameres) salina n. sp. is mainly characterized by having reduced pseudolabia, lips absent, six bifid teeth, males with lateral alae, four rows of somatic spines and length ratio of spicules 1:12-32, and large females with eggs lacking polar filaments. The acuariid, Echinuria skrjabinensis is described and illustrated, this finding represent the second report of this nematode in Argentina and the first record in flamingos. This is the first record of helminths parasitizing wild Chilean Flamingos, but it is not possible to ensure that they accomplish their life cycle in this system of lakes, because the migratory movements of the population of flamingos studied are unknown.

Digenean fauna in raptors from northeastern Argentina, with the description of a new species of Strigea (Digenea: Strigeidae).

The digenean fauna of six species of falconiform birds from northeastern Argentina is reported and a new species and several new hosts and geographical records are presented. Strigea proteolytica n. sp. (Strigeidae) is described from Buteogallus urubitinga and distinguished from their congeners by the combination of the following characters: plump body, conspicuous proteolytic gland, forebody with scarce vitelline glands, copulatory bursa with a well developed muscular ring (Ringnapf), and absence of true neck region in hindbody. Six previously known species are breifly described: Strigea falconis brasiliana Szidat, 1929 (Strigeidae) from Milvago chimachima and Caracara plancus; Neodiplostomum travassosi Dubois, 1937 from Buteogallus meridionalis; Tylodelphys brevis Drago & Lunaschi, 2008 and Posthodiplostomum macrocotyle Dubois, 1937 (Diplostomidae) from Busarellus nigricollis; Spaniometra variolaris (Fuhrmann, 1904) (Cyclocoelidae) and Megalophallus deblocki Kostadinova, Vaucher & Gibson, 2006 (Microphallidae) from Rostrhamus sociabilis. Literature records and information on distribution and host-parasite relationships is presented.

Digenean parasites of the great antshrike, Taraba major (Aves: Thamnophilidae), from Argentina, with a description of a new species of the genus Strigea (Strigeidae).

During a survey of birds from Argentina, two species of Digenea, one of them new, were found parasitizing the great antshrike, Taraba major (Vieillot) (Aves: Thamnophilidae). The strigeid, Strigea orbiculata sp. n. is characterized by having a body plump, a copulatory bursa without a membraneous fold ('Ringnapf'), entire testes, eggs with miracidia with eye-spots, by the arrangement of vitelline follicles in the forebody, which are densely distributed from its anterior edge, and by the absence of a neck region in the hindbody. Among the known Neotropical species of Strigea Abildgaard, 1790, only five share with Strigea orbiculata sp. n. the body shape and the distribution ofvitelline follicles in the forebody: Strigea caluri Dubois, 1962, S. elliptica (Brandes, 1888), S. inflecta Lunaschi et Drago, 2012, S. nugax Szidat, 1928 and S. sphaerocephala (Westrumb, 1823 nec Brandes 1888). However, S. caluri can be easily distinguished by having a membraneous fold in the copulatory bursa originated from 'Ringnapf', and multilobed testes. Strigea elliptica differs mainly by having a well developed 'Ringnapf' and the remaining species differ principally by metrical characters. The dicrocoeliid, Lyperosomum oswaldoi (Travassos, 1919) is reported for the first time from Argentina and T. major represents its new definitive host. The host specificity ofNeotropical Strigea spp. is discussed and an updated list of records of their hosts is provided.

Species of Strigea (Digenea: Strigeidae), parasites of the savanna hawk Buteogallus meridionalis (Aves: Accipitridae) from Argentina, with the description of a new species.

A new strigeid digenean, Strigea meridionalis sp. n., is described from the small intestine of the savanna hawk, Buteogallus meridionalis (Latham) (Aves: Accipitridae), from Formosa Province, Argentina. This species is characterised by the absence of a neck region in the hindbody, the presence of entire testes, a copulatory bursa with a membranous fold originated from the muscular ring (Ringnapf) and by the arrangement of vitelline follicles in the forebody. Other two strigeid species collected from the savanna hawk, Strigea elliptica (Brandes, 1888) and Strigea microbursa Pearson et Dubois, 1985, are described and illustrated. Strigea microbursa is reported for the first time from the Neotropical Region and B. meridionalis represents a new host record for S. elliptica. These findings allow us to increase the knowledge of these species, adding new metric and morphological data. A key to the species of the Neotropical Strigea Abildgaard, 1790 is presented including data on their geographical distribution.

First report of adult specimens of Sphincterodiplostomum musculosum (Digenea, Diplostomidae).

Sphincterodiplostomum musculosum Dubois, 1936 (Diplostomidae, Diplostominae) was originally described on the basis of specimens collected from the intestine of agami heron, Agamia agami (Gmelin) (Ardeidae), in Mato Grosso, Brazil. The original description of this species was brief because it was based on a few immature specimens. The purpose of this paper is to describe the detailed morphological study of several adult specimens of S. musculosum obtained from the intestine of the great egret, Ardea alba L. (Ardeidae), from Argentina which revealed new characters. This represents a new host record and a new record in birds in Argentina.