Systematic Parasitology最新文献

This study describes Renicola websterae n. sp., a newly identified kidney fluke (Renicolidae: Trematoda) infecting two penguin species from New Zealand, the little blue penguin (Eudyptula novaehollandiae) and the Fiordland crested penguin (Eudyptes pachyrhynchus). Morphological and molecular analyses, including phylogenies based on cox1 and 28S genes, confirmed the distinctiveness of R. websterae. Key morphological features were discerned to be statistically comparable across five developmental stages, facilitating detailed characterization even in less mature specimens. A putative second, genetically distinct Renicola sp. was identified in Fiordland crested penguins and intermediate fish hosts, indicating a potential trophic link, and partly completing the known life cycle. We discuss the fact that kidney flukes have only been found in these two penguins and not in other New Zealand species, and the ecological and host-specificity factors likely influencing parasite distribution. This work represents the first record of a named Renicola species from New Zealand and only the second species found in penguins worldwide.

Pentastomids are a group of crustaceans adapted for parasitic life. In South America, twenty-five species have been recorded, with only nine species reported in Argentina. Only three studies have focused on the molecular analysis of pentastomids in South America. Therefore, the aim of this work is to report the sequences of two pentastomids found in Argentina. A "yarara grande" (Bothrops alternatus) and a common swamp snake (Erythrolamprus poecilogyrus) were found dead on roads in northeastern Argentina and examined for parasites. Pentastomids were found in the lungs, removed, and preserved in 96% ethanol for molecular analysis. DNA was extracted, and the 28S and COI genes were amplified. The genetic analysis revealed the presence of Porocephalus cf. crotali in B. alternatus and Kiricephalus cf. coarctatus in E. poecilogyrus. This study provides the first South American COI sequences for adults of these species. Additionally, we report the first 28S sequence for K. cf. coarctatus. Furthermore, these results suggest discordance between morphological classification and molecular data at the family and subfamily levels. Further research on genus morphology and more comprehensive genetic data are required to definitively resolve the taxonomic placement of these families and their constituent genera.

This study provides a comprehensive account of Nosema canburensis sp. nov., a newly discovered microsporidian species from the Italian striped bug, Graphosoma italicum Müller (Hemiptera: Pentatomidae), including its morphological, ultrastructural, and molecular phylogeny. The sporogonic proliferation of the current microsporidium occurs by binary division and usually results in chain formation as in Nosema members. The mature spores are ovoid/ellipsoidal in shape with an average length of a 4.44 ± 0.57 μm (3.48-6.55; n= 100, fixed) and a width of 2.27 ± 0.23 μm (1.67-2.92; n=100, fixed). The microsporidiosis is systemic, but the infection level is highest in the mid-gut of adult samples. The mature spores have isofilar polar filaments that make 10-11 coils. There is a difference in size between the anterior coils and the distal coils. The distal coils, which formed a triangle, were arranged in groups of three and located in close proximity to the center of the posterior part of the mature spores.

Cochimibdella mexicana n. gen. n. sp. is described based on morphological data and comparative analysis of DNA sequences, including two mitochondrial (cytochrome oxidase subunit I and 12s rRNA) and nuclear (18S rRNA and 28S rRNA) loci. Leech specimens were found in the mantle cavity and external surface of the octopus Octopus bimaculatus from Bahía de los Ángeles, Baja California, México. In vivo observations of recently hatched leeches in the laboratory confirm a broad prey range, including fishes, the most common hosts of the family species. The new taxon differs from species of the family Piscicolidae in possession of weakly developed tubercles in a3 of the urosome. In addition, molecular analysis places Cochimibdella mexicana n. gen. n. sp. sister to Austrobdella californiana and Myzobdella lugubris. This work amends a previous record of the elasmobranch-feeding leech Pontobdella (=Stibarobdella) moorei as a parasite of Octopus bimaculatus from the type locality of the new taxon.

Additional morphology, new sequence (482 bp SSU rRNA gene, 902 bp ITS Region), and ecological data for Gyrodactylus olsoni Mizelle and Kritsky, 1967 parasitizing longjaw mudsucker, Gillichthys mirabilis Cooper (Gobiiformes: Gobiidae) from coastal waters of California, are provided. The parasite was found on 96% of 617 mudsuckers collected from Tijuana Estuary to Arcata Bay, California. It was present on gills, fins, and body surfaces. Samples from gills and fins shared identical sequence data indicating a lack of site specificity for the parasite. The new material matched the description of G. olsoni in features of the haptoral hard parts and MCO, but trichrome-stained specimens and scanning electron microscopy showed a pair of shallow tissue pads immediately anterior to the folded anchor roots. The pads, which appear partially hardened on the curved inner surface typically with two thin marginal ribs each, likely serve as a cushioning brace for any forward action of the folded anchor roots. Similar pads have only occasionally been reported in Gyrodactylus, with one species being G. proterorhini Ergens, 1967 from gobies in European freshwaters. Based on available sequences, the SSU rRNA gene was most similar to G. curemae Conroy and Conroy, 1985 from a mullet in coastal Venezuela, while the ITS was most similar to G. proterorhini. The relationship of G. olsoni to other species in the genus is discussed with support of a molecular phylogeny that finds G. olsoni to be a member of a widespread, mostly marine lineage that has radiated along with gobiid and blenniid fishes during their global radiation. Gyrodactylus olsoni has not yet been found on other species of gobies.

Sequences of the ITS1-5.8S-ITS2 rDNA of Gyrodactylus alviga Dmitrieva & Gerasev, 2000 from Merlangius merlangus L. (Gadiformes: Gadidae) in the Black Sea were obtained for the first time. Gyrodactylus alviga is 0.2% distinct from G. pterygialis Bychowsky & Polyansky, 1953 parasitising the gadid fish Pollachius virens L. in the Norwegian Sea and Gyrodactylus sp. from Microgadus tomcod Walbaum of the same fish family in the Northwest Atlantic, based on the genetic variability of the ITS region. The most species-specific ITS1 region was identical in both species. The differences in the ITS2 secondary structure and compensatory base changes in its hairpins between G. alviga and G. pterygialis were not observed. Morphometric comparison of G. alviga and G. pterygialis also showed no significant differences. On this basis, G. alviga is synonymised with G. pterygialis and a redescription of the latter is presented, including G. alviga new syn. Findings of this species in the White and Bering Seas, and possibly off the northeastern coast of North America, require confirmation based on both morphological and molecular data. The results of this study show that G. pterygialis has a wider distribution than previously known. The good concordance of the secondary structure of the first ITS2 hairpin with the phylogenetic reconstruction of Gyrodactylus species based on the whole ITS region was revealed, which is of interest for further studies on the phylogenetic systematics of Gyrodactylus.

The Indian species of the genus Canalirogas van Achterberg & Chen, 1996 are revised. Four new species, Canalirogas multinigratus Gupta & van Achterberg sp. nov. and C. subtransversus Gupta & van Achterberg sp. nov. from Meghalaya (north-eastern India); C. oblongus Gupta & van Achterberg sp. nov. from Assam (north-eastern India) and Canalirogas omninopallidus Gupta & van Achterberg sp. nov. from Karnataka (southern India) are illustrated and described. An illustrated key to the Indian species of Canalirogas is provided.

Pulmovermis cyanovitellosus Coil and Kuntz, 1960 is a species of hemiurid trematode that localizes in the lung of sea snakes, an unusual trait for this group of parasites. Recent molecular phylogenetic studies based on 28S rRNA gene sequences have shown that this species is closely related to members of the genus Lecithochirium Lühe, 1901. This finding is unexpected given that Pulmovermis Coil and Kuntz, 1960 and Lecithochirium are currently classified in different subfamilies of Hemiuridae (Pulmoverminae Sandars, 1961 vs. Lecithochiriinae Lühe, 1901). To investigate this discrepancy, we conducted a comparative morphological study on new specimens of P. cyanovitellosus collected from the same locality as those in our previous research. These new specimens were compared with the paragenophores from our earlier study and with existing descriptions in literatures. This study provides the following new morphological data regarding P. cyanovitellosus: body surface covered with minute scales; massive muscular pads present on both sides of body at level of terminal genitalia; small esophageal pouch and Drüsenmagen present; seminal vesicle connecting to pars prostatica via aglandular duct; small, cylindrical sinus-sac present; ejaculatory vesicle absent; Juel's organ present; metraterm separated from uterus by conspicuous sphincter and connecting to distal end of pars prostatica. Additionally, we assessed the phylogenetic relationships of P. cyanovitellosus using the 28S rRNA gene, the internal transcribed spacer 2 (ITS2), and the cytochrome c oxidase subunit I (COI) gene markers. Phylogenetic analyses based on these markers demonstrated that P. cyanovitellosus clustered with species of Lecithochirium. Based on this molecular evidence, we conclude that Pulmovermis is a junior synonym of the genus Lecithochirium, and propose L. cyanovitellosum (Coil and Kuntz, 1960) Urabe and Sokolov comb. nov. Given the morphological similarities between Pulmovermis and Hydrophitrema Sandars, 1960, we also propose synonymizing the latter with Lecithochirium, and L. giganticum (Sandars, 1960) Urabe and Sokolov comb. nov. and L. pingtanense (Wang, 1980) Urabe and Sokolov comb. nov. are proposed. As a result, Pulmoverminae should be considered a junior synonym of Lecithochiriinae Lühe, 1901.

The nutria (Myocastor coypus) is a semiaquatic rodent that originally inhabited South America. However, the animals have spread to different continents as alien species, and their numbers are quickly increasing, especially in North America, Europe, and Eastern Asia including Japan. Although nutrias have been suggested to serve as reservoirs for pathogens, including parasites, there have been few reports on this subject. In the present study, we surveyed the gastrointestinal parasites in nutrias living in Japan to better understand their prevalence in nutrias. We collected 72 samples of intestinal contents or feces from nutrias in Osaka and Okayama Prefectures. We found that 49 (68.1 %) samples were positive for Eimeria parasites, and two types of oocysts were identified: ellipsoidal (Type A) and subspherical (Type B) oocysts. In addition, Strongyloides myopotami was detected in 44 samples, and Capillaria spp. and Fasciola spp. were detected in one and three samples, respectively. Based on the morphologies of the detected Eimeria oocysts, Types A and B were identified to be E. coypi and E. fluviatilis, respectively. Phylogenetic analyses after PCR and sequencing targeting the cytochrome c oxidase subunit I gene placed the sequences of E. fluviatilis (Type B) as a cluster between the sequences of Eimeria derived from rodents. The sequences of the three subgenotypes of E. coypi (Type A) were included in the cluster containing the sequences of Eimeria spp. from rodents of multiple species, which is referred to as the Apionodes supercluster, and is separate from other clades. It has been suggested that Eimeria spp. from rodents in this cluster can quickly adapt to infect different hosts. Although further analyses are needed to construct more detailed phylogenetic trees, our results revealed the genetical positions of Eimeria spp. in nutrias. In addition, our results may be helpful when considering host specificity as well as host switching by the pathogen.

Opistholecithum sandugaense n. g. n. sp. was collected from the intestine of Oncorhynchus keta (Walbaum) in the Nezhinka (=Sanduga) River, Primorsky region, Russia. Based on the position of the vitellarium in hindbody and significant genetic differentiation, ten species from the genus Lecithaster Lühe, 1901 were transferred to the newly established Opistholecithum as follows: O. gibbosum (Rudolphi, 1802) n. comb., O. macrocotyle (Szidat & Graefe, 1967) n. comb., O. micropsi (Zdzitowiecki, 1992) n. comb., O. salmonis (Yamaguti, 1934) n. comb. According to the morphometrics and topology of the internal organs, O. sandugaense appears similar to O. salmonis. These species are distinct based on novel sequence data - 28S rRNA gene (p-distances 0.4%) and the cox1 mtDNA gene (p-distances 4.4-4.8%). Large-scale phylogeny reconstruction showed that the lecithasterid subfamily Lecithasterinae sensu stricto include two genera Lecithaster (type taxon) and Opistholecithum n. g.; other genera Lecithophyllum and Aponurus were transferred to the family Lecithophyllidae n. stat. Based on the morphological features, we consider four subfamilies Lecithasterinae, Trifoliovariinae, Prolecithinae and Macradenininae belonging to Lecithasteridae. Analysis of indels in the 28S divergent domains proved to be a robust technic for family delimitation within the superfamily Hemiuroidea. Especially it allows to reveal the molecular symplesiomorphies affecting phylogenetic reconstructions. Taxonomic rearrangements proposed in this study are supplemented by dichotomous keys: (1) for two genera of the subfamily Lecithasterinae; (2) for the genus Opistholecithum; (3) for the genus Lecithaster; (4) for six closely related hemiuroid families, with Lecithophyllidae n. stat. (genera Lecithophyllum, Aponurus, Monorchiaponurus, Weketrema) and Merlucciotrematidae n. fam. (Merlucciotrema).