Phylogenetic assessment of some Palearctic Allocreadium spp. (Trematoda, Gorgoderoidea: Allocreadiidae).

The genus Allocreadium is a group of digenetic trematodes whose adult representatives mainly parasitize the intestines of freshwater fishes. The aim of this research is to reconstruct the phylogeny of four Palearctic species of this genus, Allocreadium dogieli, Allocreadium isoporum, Allocreadium papilligerum, and Allocreadium sp. ex Oreoleuciscus potanini from Mongolia. The DNA sequences of the 28S rRNA gene and the rDNA ITS2 region were obtained and then analyzed for phylogenetic inference. The analysis is complemented with the morphological descriptions for all four species. Phylogenetic analyses show that the newly obtained isolate of A. isoporum appeared to be genetically similar to previously obtained isolates of A. isoporum. Allocreadium dogieli probably belongs to the same evolutionary lineage of Allocreadium as A. crassum, while A. papilligerum to the same evolutionary lineage as Alocreadium transversale ex Cobitis taenia from Lithuania, but the detailed species composition of these lineages requires further elucidation. Allocreadium sp. was genetically close to Allocreadium sp. ex P. phoxinus from Primorski Krai, Russia, and a group of these Allocreadium had a sister relationship with Allocreadium khankaiensis. Our findings contradict some recent hypotheses about the phylogeography of Allocreadium spp.

Morphology and phylogeny of the parasitic nematode Mooleptus rabuka (Machida, Ogawa & Okiyama, 1982) (Rhabditida, Spirurina: Mooleptinae nom. nov.), with notes on taxonomy of the family Gnathostomatidae.

The nematode Mooleptus rabuka is recorded in the digestive tract of catshark Apristurus fedorovi caught at the Imperial Ridge (Pacific Ocean). Important morphological features such as the number of cephalic and caudal papillae, the position of amphids and the shape of the gubernaculum are detailed in this parasite species. According to the phylogenetic analyses based on the 18S ribosomal RNA gene sequences, M. rabuka forms a lineage, Mooleptinae nom. nov., which is close to the gnathostomatid genus Echinocephalus (maximum likelihood analysis), or else forms a polytomy with this genus and the lineages of Anguillicola + Spiroxys and Tanqua + 'Linstowinema' sp. (Bayesian inference analysis). Overall, our findings do not support the monophyly of the Gnathostomatidae. We elevate spiroxyines to the family status, Spiroxyidae stat. nov., and temporarily consider the Gnathostomatidae to include the following subfamilies: Ancyracanthinae Yorke & Maplestone, 1926, Gnathostomatinae Railliet, 1895 sensu lato and Mooleptinae nom. nov. The name Mooleptinae nom. nov. is suggested instead of the Metaleptinae Moravec & Nagasawa, 2000, which is based on a preoccupied generic name Metaleptus Machida, Ogawa & Okiyama, 1982.

Redescription and supplementary molecular characteristics of Aspidogaster ijimai Kawamura, 1915 (Trematoda, Aspidogastrea, Aspidogastridae), a parasite of Cyprinus carpio Linnaeus, 1758 s. lato (Actinopterygii) and freshwater bivalves in East Asia.

A detailed morphological description and ribosomal DNA (rDNA) sequence molecular data for Aspidogaster ijimai from Japan are provided. Morphological analysis, including a description of the cirrus-sac, indicate the conspecificity of Japanese and continental East Asian A. ijimai specimens. Analysis of ITS1-5.8S-ITS2 rDNA sequences of Japanese, Chinese and Russian specimens confirmed the morphological results. Phylogenetic analysis using ITS rDNA sequences confirmed that A. ijimai is a sister species for Aspidogaster chongqingensis. Median-joining network analysis showed an initial molecular differentiation step of Russian specimens from group of Japanese-Chinese samples. Our 28S rDNA results based on maximum likelihood (ML) and Bayesian (BI) phylogenetic analyses indicated well-supported monophyly of the Aspidogaster conchicola + A. ijimai group, a finding that indicates that these species are congeneric. At the same time, our data demonstrated that the genus Lobatostoma is paraphyletic and the family Aspidogastridae is polyphyletic, results that confirm previous studies.

Morphology and phylogeny of Henneguya oviperda infecting oocytes of Esox lucius, with description of parasite-induced histopathology.

Henneguya oviperda (Cohn, 1895) (Myxozoa: Myxobolidae) is a parasite infecting oocytes of the northern pike Esox lucius Linnaeus, 1758 (Actinopterygii: Esocidae). Infected oocytes are surrounded by all oocyte layers, some of them thinner and less visible than intact oocytes. A mature plasmodium of H. oviperda fills the entire internal space of the oocytes at the secondary growth phase, rendering the nucleus and organelles of the latter undetectable. Apart from the observed degradation of internal structures, alterations in the envelopes of the infected oocytes, and the deformation of the intact oocytes adjacent to them, no other developmental anomalies have been found in the reproductive products of female northern pike. Mature spores of H. oviperda have oval bodies with polar capsules of almost equal size and caudal projections that are on average equal to the spore body length. Phylogenetic analysis comparing 18S rDNA sequences placed H. oviperda into a clade of esocid-infecting species of the genus Henneguya and also supported H. psorospermica as a sister species.

Records of opecoeline species Pseudopecoelus cf. vulgaris and Anomalotrema koiae Gibson & Bray, 1984 (Trematoda, Opecoelidae, Opecoelinae) from fish of the North Pacific, with notes on the phylogeny of the family Opecoelidae.

Opecoelid species Pseudopecoelus cf. vulgaris and Anomalotrema koiae Gibson & Bray, 1984 were found in fish collected in the boreal waters of the North Pacific. Pseudopecoelus cf. vulgaris differs from Pseudopecoelus vulgaris (Manter, 1934) in terms of the egg size. This is the first record of A. koiae in the North Pacific, and the second of Pseudopecoelus cf. vulgaris. Previously, A. koiae was recorded only in North Atlantic fish. Partial sequences of 28S rDNA obtained for these two species and six other previously unsequenced representatives of the family Opecoelidae were analysed together with data from GenBank. Phylogenetic analysis supports the allocation of the six clades of opecoelids - Helicometrinae, Opecoelinae, Opistholebetinae, 'freshwater Plagioporinae', 'marine Plagioporinae B' and 'marine Plagioporinae C', and confirms the paraphyly of the group 'deep-sea Plagioporinae'. Our phylogeny does not support previous hypotheses about the monophyly of opecoelines with a uroproct.

Diversity of the genus Bunodera Railliet, 1896 (Trematoda: Allocreadiidae) in the northern part of Eastern Europe and North-eastern Asia, estimated from 28S rDNA sequences, with a description of Bunodera vytautasi sp. nov.

Phylogenetic relationship reconstruction and taxonomical analysis of trematodes of the genus Bunodera was carried out using 28S rDNA partial sequences along with a description and molecular characterisation of a new species, B. vytautasi sp. nov. A new species is reported from the intestine of Pungitius pungitius (Linnaeus, 1758), collected from Magadan Region, Russia. The diagnostic characters of B. vytautasi sp. nov. are the extension of vitelline fields from the oral sucker or posterior edge of the pharynx to the posterior extremity of the body, the confluence of vitelline fields within the forebody, the extension of the cirrus-sac to the posterior third of ventral sucker or further backwards with an outlet beyond the posterior edge of the sucker, and the presence of a unipartite internal seminal vesicle. Both Bayesian and Maximum Likelihood trees shared the same tree topology, in which the genus Bunodera was shown to be monophyletic. Representatives of the genus Bunodera were distributed into three well-supported clades: percid-infecting species (Eurasian species B. luciopercae and B. acerinae and North American B. luciopercae s.l.), gasterosteid-infecting species (amphi-Pacific B. mediovitellata and North American B. inconstans and B. eucaliae) and percid/gasterosteid-infecting species (Asiatic B. vytautasi sp. nov. and North American B. sacculata). Eurasian B. luciopercae and B. acerinae were more closely related to each other than to North American B. luciopercae s.l.

Phylogenetic relationships among European and Asian representatives of the genus Aspidogaster Baer, 1827 (Trematoda: Aspidogastrea) inferred from molecular data.

In the present study, phylogenetic relationships of European and Far Eastern representatives of the genus Aspidogaster Baer, 1827 were analysed: A. conchicola Baer, 1827, A. limacoides Diesing, 1834, A. ijimai Kawamura, 1915 and A. chongqingensis Wei, Huang & Dai, 2001. Based on ITS1-5.8S-ITS2 rDNA sequence data, an obvious differentiation was seen between specimens of A. limacoides sensu stricto from the European part of Russia and A. limacoides sensu Chen et al., 2010 from China (13.7%); the latter parasites were recognized as A. chongqingensis. Aspidogaster chongqingensis was more closely related to A. ijimai than to A. limacoides s. str. Specimens of A. ijimai from the Amur River, Khanka Lake (Russian Far East) and China were grouped into a single clade with low intra specific molecular differentiation (d = 0-0.3%). Specimens of A. conchicola from the European part of Russia, the Russian Far East and China also formed a single distinct clade. Genetic differentiation between European and Chinese samples of this species was two times lower (d = 0.45%) than between Russian Far East and European or Chinese samples (d = 0.96%), suggesting a long-term separate existence of A. conchicola in the Russian Far East.

New Data on the Morphology and Phylogenetic Connections of Postlepidapedon Opisthobifurcatum (Trematoda, Lepocreadioidea: Lepidapedidae), a Parasite of Antarctic and Sub-Antarctic Fishes.

The trematode Postlepidapedon opisthobifurcatum (Zdzitowiecki, 1990) is a common intestinal parasite of the gadiform fishes of the Southern Ocean. In this work, we supplement the description of the species with the anatomy of the terminal part of the reproductive system and with molecular data. The male terminal genitalia are characterised by the presence of the external seminal vesicle and cirrus-sac. The external seminal vesicle is surrounded by aciniform groups of outer prostatic cells. Groups of outer prostatic cells and proximal parts of their ducts are associated with a thin-walled membrane that is connected to the proximal edge of the сirrus-sac. The cirrus-sac is claviform, with a long proximal part accommodating the tubular, thin-walled internal seminal vesicle and ducts of outer prostatic cells. The female terminal genitalia are represented by a thick-walled metraterm, which is surrounded by aciniform groups of glandular cells. Phylogenetic analysis based on 28S rDNA partial sequences data placed P. opisthobifurcatum into the monophyletic group Lepidapedidae, including the species Myzoxenus insolens (Crowcroft, 1945), Intusatrium robustum Durio et Manter, 1968, and Postlepidapedon uberis Bray, Cribb et Barker, 1997. However, we were unable to detect direct phylogenetic connections between P. opisthobifurcatum and P. uberis.

Phylogenetic position of the family Orientocreadiidae within the superfamily Plagiorchioidea (Trematoda) based on partial 28S rDNA sequence.

Trematodes of the family Orientocreadiidae are mostly parasites of freshwater fishes. Here, the phylogenetic position of this family is inferred based on the partial 28S rDNA sequence from a representative of the genus Orientocreadium s. str.-О. pseudobagri Yamaguti, 1934. Sequences were analysed by maximum likelihood and Bayesian inference algorithms. Both approaches placed the Orientocreadiidae within a clade corresponding to the superfamily Plagiorchioidea and supported the family Leptophallidae as a sister taxon.

The Diversity of Parasites in the Chinese Sleeper Perccottus glenii Dybowski 1877 (Actinopterygii: Perciformes) under the Conditions of Large-Scale Range Expansion.

It has been found that the species composition of parasites infesting the Chinese sleeper Perccottus glenii in water bodies from the nonnative part of its range is more depleted. Here, the phylogenetic distances between parasites exceed those in the native part of the range. It has been revealed that parasitological differences between P. glenii populations from the nonnative and native parts of the range, as well as between populations inside the nonnative part, have similar composition and abundance of the host-specific and euryxenous components in the parasitic fauna. It has been shown that these differences are determined by the genesis of sites from which P. glenii is introduced, as well as the local conditions of the recipient water bodies.

[METACERCERIAE OF BRACHYPHALLUS CRENARUS RUDOLPHI, 1802 (TREMATODA: HENIURIDAE) IN PLANKTON CRUSTACEANS FROM THE PROSTOR GULF (ITURUP ISLAND, RUSSIA)].

Samples of Zooplankton collected in waters of the Prostor Gulf (Iturup Island) were examined. Metacercariae of Brachyphallus crenatus were found in copepods Pseudocalanus newmani and Acartia longiremis. This is the first record of the second intermediate hosts of this species in the North Pacific.

ACANTHOCEPHALANS PROSTHENORCHIS CF. ELEGANS (ARCHIACANTHOCEPHALA: OLIGACANTHORHYNCHIDAE), PARASITES OF PRIMATES IN THE MOSCOW ZOO.

Acanthocephalans Prosthenorchis cf. elegans were found in primates in the Moscow Zoo. The larvae of these parasites (cistacanths) were found in cockroaches Blattella germanica that had been captured near aviaries of infected animals. Descriptions and drawings of adult parasites and their larvae are given. Analysis of Prosthenorchis cf. elegans genes ITS 1 rDNA and CO 1 mtDNA shows phylogenetic relations of these parasites with several representatives of the class Archiacanthocephala. The obtained molecular data, however, do not support the monophyly of the family Oligacanthorhynchidae and the order Oligacanthorhynchida.

THE FIRST RECORD OF DIMEROSACCUS ONCORHYNCHI (TREMATODA: OPECOELIDAE) IN FISHES FROM RIVERS OF PRIMORSKY TERRITORY, RUSSIA, WITH A DISCUSSION ON ITS TAXONOMIC POSITION USING MORPHOLOGICAL AND MOLECULAR DATA.

The opecoelid trematode Dimerosaccus oncorhynchi (Eguchi, 1931) Shimazu, 1980, hitherto known only from the Japanese archipelago, has been found in three species of freshwater salmonid fish (Oncorhynchus masou, Brachymystax tumensis, Salvelinus curilus) from rivers of Primorsky Territory, the Sea of Japan basin, Russia. This is the first record of the parasite in the continental part of Asia. Fishes B. tumensis and S. curilus are new hosts for D. oncorhynchi. The ecological notes, morphological description and drawings of the found trematodes clarifying the morphology of the male reproductive system are given. In the present study phylogenetic relationships of the species D. oncorhynchi with the related taxa were revealed using partial sequences of the 28S rDNA. Obtained results indicate the validity of D. oncorhynchi as the member of the subfamily Opecoelinae, which was closely related to the genus Opecoeloides, a representative of this subfamily.

[New data on trematodes of Antarctic fish].

Deepwater fishes from the Amundsen Sea, d'Urville Sea, Ross Sea, Cooperation Sea, Weddell Sea, and open waters of the South-West part of the Pacific sector of the Antarctic were examined. Fourteen species of trematodes were found. Muraenolepitrema magnatestis Gaevskaya et Rodjuk, 1988 and Helicometrina sp. were found in the Antarctic for the first time. Muraenolepitrema magnatestis was redescribed and basing on this, diagnosis of the genus Muraenolepitrema was amended. Muraenolepitrema magnatestis possesses the uroproct and glandular cells that are loosely arranged around the external seminal vesicle (without a membranous sac).

[Occurrence of helminths in amphipods Gammarus lacustris Sars, 1863 (Amphipoda: Gammaridae) from Kronotskoe Lake (Kamchatka)].

Metacercariae of Crepidostomum metoecus (prevalence 2.0%), procercoids of Cyathocephalus truncatus (2.9%), and nematodes of the family Cystidicolidae (17.6%) were found in the body cavity of amphipods Gammarus lacustris from the Kronotskoe Lake. The nematodes were presented by Cystidicola farionis (third-stage juvenile) and Ascarophis sp. (adult and fourth-stage juvenile).

[Variation trends in the parasite communities of the Chinese sleeper Perccottus glenii (Actinopterygii: Odontobutidae) in its native habitat].

The diversity of parasite communities in the Chinese sleeper Perccottus glenii, at the level of single specimens and populations, is manifested through three components: the number of species, the evenness of their abundance, and the taxonomic diversity. Variations in the diversity depend on the local characteristics of water bodies, as well as the sexual and dimensional factors of the host. This study was performed in four water bodies of the Russian Far East (Primorskii krai and Sakhalin Island).

[Goussia obstinata sp. n. (Sporozoa: Eimeriidae), a new coccidian species from intestines of the Amur sleeper Perccottus Glenii Dybowski, 1877 (Perciformes: odontobutidae)].

Goussia obstinata sp. n. is described from the intestine epithelium of the Amur sleeper Perccottus glenii Dybowski, 1877 from Russia and Moldova. The species was examined in an optical microscope. Merogonic, gamogonic and sporogonic stages of the species are located in cells of the gut epithelium. Sporulation is endogenous; oocysts are released in the gut lumen. Non-sporulated oocysts are spherical or ellipsoidal; sporulated oocysts are rounded, 6.7-11.4 µm in diameter, with a colorless, single-layer, very fine and easily ruptured wall. Micropyle and oocyst residuum is absent; 1-2 small polar granules of 1.0-2.5 µm are sometimes present. Oocysts contain four compact widely oval, slightly narrow-ended sporocysts. The sheath of the sporocyst is formed of two folds divided by a slightly S-shaped longitudinal suture. Coarsely granulated, globular or oval compact sporocyst's residuumis located between sporozoites. Sausage-shaped sporozoits are subdivided by a bend into two unequal parts, being 6.4-9.8 µm (long part) and 2.6-4.8 µm (short part) long, arranged in a top-to-tail position. Our preliminary data suggests that infestation of the sleeper with the examined parasite is not associated with the morbidity and mortality of the fish. A new combination Goussia marmorata (Molnár, 1996) comb. n. is proposed for a species originally described in the content of the genus Eimeria Schneider, 1875 from the Western tubenose goby Proterorhinus semilunaris.

[New data on parasite fauna of the Chinese sleeper Perccottus glenii (Actinopterygii: Odontobutidae) in Primorsky Territory with the description of a new myxozoan species from the genus Myxidium (Myxozoa: Myxidiidae)].

Examination of 116 individuals of Perccottus glenii from water bodies of Primorsky Territory of Russia (the Khanka Lake basin and the Peter the Great Bay basin) revealed the presence of 35 species/taxa of parasites. We give a description of a new species, Myxidium shedkoae sp. nov. Spherical plasmodoa of M. shedkoa sp. nov. are located in the gall bladder; spores are fusiform, with protrusive, pointed, or truncated-cone-shaped poles. The length of spores constitutes 12.6-14.9 (13.4) microm; width, 7.1-8.6 (7.9) microm; shell valves possess 8-10 ridges forming "papillary" pattern. Drawings and descriptions of parasites species poorly studied and recorded from Russia for the first time are given together with drawings and descriptions of some parasites determined only as genera: Triangula perccotti, Gyrodactylus sp., Phyllodistomum sp., Paracoenogonimus ussuriensis (metacercaria), Cyathocotylidae gen. sp. (metacercaria) and Spiroxys japonicus (third-stage juvenile). Parasite fauna of P. glenii in Primorsky Territory comprises 66% of species/forms known for P. glenii in the native part of its range.

[Parasites of the introduced Amur sleeper, Perccottus glenii (Osteichthyes): alpha-diversity of parasites and age of the host].

Three age groups of the Amur sleeper have been studied: underyearlings (0+), two-year-olds (1+), and three- and four-year-olds (2+ and 3+). The long-cycle parasites prevalent in all three age groups are the merocercoids of Ophiotaenia europaea, third-instar larvae of Spiroxys contortus, and metacercaria of Isthmiophora sp. and Prohemistomidae gen. sp. Different age groups of the Amur sleeper have different roles in the life cycle of O. europaea. Underyearlings are second intermediate hosts of O. europaea, and Amur sleepers aged 1+ and older are parathenic hosts. The alpha-diversity of long-cycle parasites of the Amur sleeper increases with the age of the host.

[Parasites of underyearling kamchatka mykiss Parasalmo mykiss mykiss (Osteichithyes:Salmonidae) in the Utkholok River (North-Western Kamchatka)].

Eight species of parasites, Apiosoma piscicolum piscicolum, Apatemon sp., Diplostomum sp., Bunoderidae gen. sp., Crepidostomum metoecus, Hysterothylacium gadi aduncum, Salvelinema salmonicola, and Cucullanus truttae had been found in underyearling Kamchatka mykiss (with fork length 28-41 mm) from the Utkholok River, North-Western Kamchatka. Infestation rate of the fishes with each parasite species was rather low. Presence of C. truttae in underyearling Kamchatka mykiss could not be explained by the conceptual model of its life cycle proposed by Moravec (1979). Spatial and temporal isolation of underyearling Kamchatka mykiss and ammocoetes, as the elements of a local food web, suggest that the lamprey larvae do not participate in the transmission of C. truttae to underyearling Kamchatka mykiss.