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Sample records for digenean trematode species

  1. Digenean trematode species in the cockle Cerastodema edule: identification key and distribution along the north-eastern Atlantic shoreline

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    Montaudouin, Xavier De; Thieltges, David W.; Gam, Mériame

    2009-01-01

    host. The remaining eleven species have cockles as their second intermediate host. Water birds and fish are the definitive hosts to twelve and four species, respectively. Cockles are infected with digeneans along the latitudinal gradient from southern Morocco to the western region of the Barents Sea......-scale distribution pattern may serve as a baseline for future studies dealing with the effects of climate change on parasite-host systems. For such studies the cockle and its digenean community could be an ideal model system....

  2. A Novel Toll-Like Receptor (TLR Influences Compatibility between the Gastropod Biomphalaria glabrata, and the Digenean Trematode Schistosoma mansoni.

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    Emmanuel A Pila

    2016-03-01

    Full Text Available Schistosomiasis, a devastating disease caused by parasitic flatworms of the genus Schistosoma, affects over 260 million people worldwide especially in tropical and sub-tropical regions. Schistosomes must undergo their larval development within specific species of snail intermediate hosts, a trait that is shared among almost all digenean trematodes. This unique and long-standing host-parasite relationship presents an opportunity to study both the importance of conserved immunological features in novel immunological roles, as well as new immunological adaptations that have arisen to combat a very specific type of immunological challenge. While it is well supported that the snail immune response is important for protecting against schistosome infection, very few specific snail immune factors have been identified and even fewer have been functionally characterized. Here, we provide the first functional report of a snail Toll-like receptor, which we demonstrate as playing an important role in the cellular immune response of the snail Biomphalaria glabrata following challenge with Schistosoma mansoni. This TLR (BgTLR was identified as part of a peptide screen of snail immune cell surface proteins that differed in abundance between B. glabrata snails that differ in their compatibility phenotype to challenge by S. mansoni. The S. mansoni-resistant strain of B. glabrata (BS-90 displayed higher levels of BgTLR compared to the susceptible (M-line strain. Transcript expression of BgTLR was found to be very responsive in BS-90 snails when challenged with S. mansoni, increasing 27 fold relative to β-actin (non-immune control gene; whereas expression in susceptible M-line snails was not significantly increased. Knockdown of BgTLR in BS-90 snails via targeted siRNA oligonucleotides was confirmed using a specific anti-BgTLR antibody and resulted in a significant alteration of the resistant phenotype, yielding patent infections in 43% of the normally resistant

  3. Molecular analyses reveal high species diversity of trematodes in a sub-Arctic lake

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    Soldánová, Miroslava; Georgieva, Simona; Roháčováa, Jana; Knudsen, Rune; Kuhn, Jesper A.; Henriksen, Eirik H.; Siwertsson, Anna; Shaw, Jenny C.; Kuris, Armand M.; Amundsen, Per-Arne; Scholz, Tomáš; Lafferty, Kevin D.; Kostadinova, Aneta

    2017-01-01

    To identify trematode diversity and life-cycles in the sub-Arctic Lake Takvatn, Norway, we characterised 120 trematode isolates from mollusc first intermediate hosts, metacercariae from second intermediate host fishes and invertebrates, and adults from fish and invertebrate definitive hosts, using molecular techniques. Phylogenies based on nuclear and/or mtDNA revealed high species richness (24 species or species-level genetic lineages), and uncovered trematode diversity (16 putative new species) from five families typical in lake ecosystems (Allocreadiidae, Diplostomidae, Plagiorchiidae, Schistosomatidae and Strigeidae). Sampling potential invertebrate hosts allowed matching of sequence data for different stages, thus achieving molecular elucidation of trematode life-cycles and exploration of host-parasite interactions. Phylogenetic analyses also helped identify three major mollusc intermediate hosts (Radix balthica, Pisidium casertanum and Sphaerium sp.) in the lake. Our findings increase the known trematode diversity at the sub-Arctic Lake Takvatn, showing that digenean diversity is high in this otherwise depauperate sub-Arctic freshwater ecosystem, and indicating that sub-Arctic and Arctic ecosystems may be characterised by unique trematode assemblages.

  4. Digenea trematodes in fish of the North Adriatic Sea

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    Vesna PARADIŽNIK

    2007-12-01

    Full Text Available The paper gives an overview of trematodes that have been isolated from the north Adriatic Sea , during a 10-year research program. A total of 63 marine fish species of pelagic and benthic of the classes Chondrichthyes and Osteichthyes were analyzed. We found that 21 fish species ted digenean trematodes (33.33% prevalence, and 12 fish species are reported as hosts for the t time. During our research, 63 species of fish (total of 2659 fish were examined and 25.16 % e found invaded by endohelminths, belonging to 22 digeneans species.

  5. Morphometrics and levels of infections of digeneans in belonid fish species off the coast of Tunisia.

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    Châari, M; Derbel, H; Neifar, L

    2016-09-01

    Three species of belonid fish, Belone belone gracilis Lowe, 1839, Belone svetovidovi Collette & Parin, 1970 and Tylosurus acus imperialis (Rafinesque, 1810), caught off the eastern Tunisian coast were infected with eight species of Digenea. Among these, four species were commonly found in B. b. gracilis and are new host records for B. svetovidovi. They are: Lecithostaphylus retroflexus (Molin, 1859), Tergestia acanthocephala (Stossich, 1887) Stossich, 1899 and Aponurus laguncula Looss, 1907 in the intestine, and the metacercaria Condylocotyla pilodora Pearson and Prévot, 1985 in the pericardial sac. Four other digenean species were recorded from T. a. imperialis: Lecithostaphylus tylosuri Châari et al., 2013 and Tetrochetus coryphaenae Yamaguti, 1934 in the intestine, Oesophagotrema mediterranea Châari et al., 2011 in the oesophagus and vomer teeth, and Sclerodistomoides pacificus Kamegai, 1971 in the gall bladder. Tetrochetus coryphaenae and S. pacificus represent new host and geographical records. The spatial variation of digenean parasites within belonid host species is discussed.

  6. Does a facultative precocious life cycle predispose the marine trematode Proctoeces cf. lintoni to inbreeding and genetic differentiation among host species?

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    Valdivia, I M; Criscione, C D; Cárdenas, L; Durán, C P; Oliva, M E

    2014-03-01

    Intraspecific variability in parasite life cycle complexity (number of hosts and species of hosts in the life cycle) may have an impact how parasite genetic variation is partitioned among individual parasites, host individuals or host species within a given area. Among digenean trematodes, a three-host life cycle is common. However, a few species are precocious and may reach sexual maturity in what is typically regarded as the second intermediate host. The objective of this study was to determine whether a precocious life cycle predisposes digeneans to possible inbreeding or genetic subdivision among host species. As a study system, we used the digenean Proctoeces cf. lintoni whose metacercariae precociously mature (facultative) without a cyst wall in the gonads of multiple sympatric species of keyhole limpets (Fissurella spp.), typically regarded as the second intermediate hosts. Genotyped parasites were collected from four species of limpets and the clingfish Sicyases sanguineus, the third and final host where sexual maturity occurs. We found very high microsatellite diversity, Hardy-Weinberg equilibrium over all genotyped individuals, and little to no genetic structuring among parasites collected from the different host species. The fact that metacercariae do not encyst in the keyhole limpets, coupled with the high mixing potential of an aquatic environment, likely promote panmixia in local populations of P. cf. lintoni.

  7. Digenean species diversity in teleost fishes from the Gulf of Gabes, Tunisia (Western Mediterranean

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    Derbel H.

    2012-05-01

    Full Text Available This study is the first attempt to survey the diversity of fish digeneans in the Gulf of Gabes (southern coast of Tunisia. A total of 779 fishes belonging to 32 species were sampled. 53 species of Digenea belonging to 15 families were recorded. Among these species, 24 are reported for the first time from the coast of Tunisia. We report one new host record, Lecithochirium sp. from Sardinella aurita. The Hemiuridae is the dominant family. A host-parasite list is presented with the information on the prevalence, abundance and mean intensity of each species collected. The diversity of Digenea is compared with other localities in the Mediterranean Sea and the northern east of Tunisia. The Gulf of Gabes shows the lowest diversity linked to the anthropogenic activities and impact of exotic species. The use of Digenea as indicators of the state of the ecosystem is discussed.

  8. Using larval trematodes that parasitize snails to evaluate a saltmarsh restoration project

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    Huspeni, Todd C.; Lafferty, Kevin D.

    2004-01-01

    We conducted a Before-After-Control-Impact (BACI) study using larval digeneans infecting the California horn snail, Cerithidea californica, to evaluate the success of an ecological restoration project at Carpinteria Salt Marsh in California, USA. Digenean trematodes are parasites with complex life cycles requiring birds and other vertebrates as final hosts. We tested two hypotheses for prevalence and species richness of larval trematodes in C. californica: (1) prior to the restoration, sites to be restored would have lower trematode prevalence and species richness relative to unimpacted control sites, and (2) that these differences would diminish after restoration. The sites to be restored were initially degraded for trematode species. They had a mean trematode prevalence (12%) and species richness (4.5 species) that were lower than control sites (28% trematode prevalence and 7 species). Despite the differences in prevalence, the proportional representation of each trematode species in the total community was similar between sites to be restored and control sites. Over the six years following restoration, trematode prevalence nearly quadrupled at restored sites (43%) while the prevalence at control sites (26%) remained unchanged. In addition, species richness at restored sites doubled (9 species), while species richness at the control sites (7.8 species) did not change. Immediately after restoration, the relative abundance of trematode species using fishes as second intermediate hosts declined while those using molluscs as second intermediate hosts increased. Trematode communities at restored and control sites gradually returned to being similar. We interpret the increase in trematode prevalence and species richness at restored sites to be a direct consequence of changes in bird use of the restored habitat. This study demonstrates a new comparative technique for assessing wetlands, and while it does not supplant biotic surveys, it informs such taxonomic lists. Most

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

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    Drago, Fabiana B; Lunaschi, Lía I; Draghi, Regina

    2014-04-03

    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.

  10. Small estuarine fishes feed on large trematode cercariae: Lab and field investigations

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    Kaplan, A.T.; Rebhal, S.; Lafferty, K.D.; Kuris, A.M.

    2009-01-01

    In aquatic ecosystems, dense populations of snails can shed millions of digenean trematode cercariae every day. These short-lived, free-living larvae are rich in energy and present a potential resource for consumers. We investigated whether estuarine fishes eat cercariae shed by trematodes of the estuarine snail Cerithidea californica. In aquaria we presented cercariae from 10 native trematode species to 6 species of native estuarine fishes. Many of these fishes readily engorged on cercariae. To determine if fishes ate cercariae in the field, we collected the most common fish species, Fundulus parvipinnis (California killifish), from shallow water on rising tides when snails shed cercariae. Of 61 killifish, 3 had recognizable cercariae in their gut. Because cercariae are common in this estuary, they could be frequent sources of energy for small fishes. In turn, predation on cercariae by fishes (and other predators) could also reduce the transmission success of trematodes. ?? 2009 American Society of Parasitologists.

  11. First documentation and molecular confirmation of three trematode species (Platyhelminthes: Trematoda) infecting the polychaete Marenzelleria viridis (Annelida: Spionidae).

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    Phelan, Krystin; Blakeslee, April M H; Krause, Maureen; Williams, Jason D

    2016-01-01

    Polychaete worms are hosts to a wide range of marine parasites; yet, studies on trematodes using these ecologically important species as intermediate hosts are lacking. During examination of the spionid polychaete Marenzelleria viridis collected on the north shore of Long Island, New York, putative trematode cysts were discovered in the body cavity of these polychaetes. In order to verify these cysts as metacercariae of trematodes, specimens of the eastern mudsnail Ilyanassa obsoleta (a very common first intermediate host of trematodes in the region) were collected for molecular comparison. DNA barcoding using cytochrome C oxidase I regions confirmed the presence of three species of trematodes (Himasthla quissetensis, Lepocreadium setiferoides, and Zoogonus lasius) in both M. viridis and I. obsoleta hosts. Brown bodies were also recovered from polychaetes, and molecular testing confirmed the presence of L. setiferoides and Z. lasius, indicating an immune response of the polychaete leading to encapsulation of the cysts. From the 125 specimens of M. viridis collected in 2014, 95 (76.8 %) were infected with trematodes; of these 95 infected polychaetes, 86 (90.5 %) contained brown bodies. This is the first confirmation that trematodes use M. viridis as a second intermediate host and that this intermediate host demonstrates a clear immune response to metacercarial infection. Future research should explore the role of these polychaetes in trematode life cycles, the effectiveness of the immune response, and transmission pathways to vertebrate definitive hosts.

  12. Four marine digenean parasites of Austrolittorina spp. (Gastropoda: Littorinidae) in New Zealand: morphological and molecular data.

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    O'Dwyer, Katie; Blasco-Costa, Isabel; Poulin, Robert; Faltýnková, Anna

    2014-10-01

    Littorinid snails are one particular group of gastropods identified as important intermediate hosts for a wide range of digenean parasite species, at least throughout the Northern Hemisphere. However nothing is known of trematode species infecting these snails in the Southern Hemisphere. This study is the first attempt at cataloguing the digenean parasites infecting littorinids in New Zealand. Examination of over 5,000 individuals of two species of the genus Austrolittorina Rosewater, A. cincta Quoy & Gaimard and A. antipodum Philippi, from intertidal rocky shores, revealed infections with four digenean species representative of a diverse range of families: Philophthalmidae Looss, 1899, Notocotylidae Lühe, 1909, Renicolidae Dollfus, 1939 and Microphallidae Ward, 1901. This paper provides detailed morphological descriptions of the cercariae and intramolluscan stages of these parasites. Furthermore, partial sequences of the 28S rRNA gene and the mitochondrial gene cytochrome c oxidase subunit 1 (cox1) for varying numbers of isolates of each species were obtained. Phylogenetic analyses were carried out at the superfamily level and along with the morphological data were used to infer the generic affiliation of the species.

  13. The Mediterranean: high discovery rates for a well-studied trematode fauna.

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    Pérez-del-Olmo, Ana; Kostadinova, Aneta; Gibson, David I

    2016-03-01

    Our knowledge of trematode diversity in Mediterranean Sea fishes is based on many contributions since the early 1800s (e.g. by Rudolphi, Stossich, Looss, Bartoli, Bray and Gibson). We have updated data from the Natural History Museum Host-Parasite Database and listed 302 digenean trematode species allocated to 146 genera in 29 families from 192 fish species (27% of the known fish-fauna) belonging to 76 families. The most diverse (with 31-41 species) digenean families (Opecoelidae Ozaki, 1925, Didymozoidae Monticelli, 1888 and Hemiuridae Looss, 1899) represent more than a third of the total richness (36% of species) and have been most frequently recorded (43% of the records). The overall mean number of species per host is close to recent global estimates for digenean richness in teleosts (1.57 vs 2.04, respectively), indicating a high diversity in the Mediterranean. The most diverse host families are also the best studied. However, three speciose host families (Rajidae de Blainville, Gobiidae Cuvier and Myctophidae Gill) appear under-studied and no digenean reports exist for 94 of 169 fish families present in the Mediterranean. Thus, although Mediterranean fishes appear well studied, further efforts are needed. Nevertheless, the descriptions of a large number of new taxa since 2000 indicate that focused efforts have resulted in a high discovery rate (2.4 species per year). Many of these new (often cryptic) taxa are the result of combined morphological and molecular methods, which promise more reliable estimates of digenean diversity in this region. We provide host-parasite lists for 192 species of fish in the Mediterranean comprising 890 host-parasite associations.

  14. Detection and Management of Air Sac Trematodes (Szidatitrema Species) in Captive Multispecies Avian Exhibits.

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    Delaski, Kristina M; Nelson, Sudona; Dronen, Norman O; Craig, Thomas M; Pond, Joel; Gamble, Kathryn C

    2015-12-01

    From 2 exhibits in a zoological collection, 2 juvenile fairy bluebirds ( Irena puella ) and 1 adult blue-grey tanager (Thraupis episcopus) died within 3 months of one another. The cause of death was attributed to air sac trematodes, which were identified as Szidatitrema species based on morphology of adult trematodes and miracidia isolated from a snail intermediate host. To determine the extent of trematodiasis in the collection, individual exhibits within the same building as the original presenting cases were assessed, with birds representing 27 avian species from 9 orders. Sampling consisted of individual (n = 244) and pooled same-species group (n = 193) fecal examinations, and for some individuals, and tracheal swab (n = 106), resulting in a total of 543 samples. In addition, tracheal swabs were performed on 14 birds for comparative cytology, but no parasites were found. Flukes were positively identified in 4 tracheal swab samples (4%), 37 individual fecal samples (15%), and 52 of the group fecal samples (27%). When results of the swab method were compared with those of fecal examination, fecal testing was significantly associated (P birds housed in exhibits known to have snail populations. Snail control methods also were initiated in all exhibits. Treatment with praziquantel was carried out on a case-by-case basis, and included oral, parenteral, and nebulized administration. Although control measures were expected to manage the infection and reduce distribution of the parasite to other collections, complete eradication of trematodes in the population is unlikely.

  15. De Novo Transcriptome Characterization of a Sterilizing Trematode Parasite (Microphallus sp. from Two Species of New Zealand Snails

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    Laura Bankers

    2017-03-01

    Full Text Available Snail-borne trematodes represent a large, diverse, and evolutionarily, ecologically, and medically important group of parasites, often imposing strong selection on their hosts and causing host morbidity and mortality. Even so, there are very few genomic and transcriptomic resources available for this important animal group. We help to fill this gap by providing transcriptome resources from trematode metacercariae infecting two congeneric snail species, Potamopyrgus antipodarum and P. estuarinus. This genus of New Zealand snails has gained prominence in large part through the development of P. antipodarum and its sterilizing trematode parasite Microphallus livelyi into a textbook model for host–parasite coevolutionary interactions in nature. By contrast, the interactions between Microphallus trematodes and P. estuarinus, an estuary-inhabiting species closely related to the freshwater P. antipodarum, are relatively unstudied. Here, we provide the first annotated transcriptome assemblies from Microphallus isolated from P. antipodarum and P. estuarinus. We also use these transcriptomes to produce genomic resources that will be broadly useful to those interested in host–parasite coevolution, local adaption, and molecular evolution and phylogenetics of this and other snail–trematode systems. Analyses of the two Microphallus transcriptomes revealed that the two trematode types are more genetically differentiated from one another than are the M. livelyi infecting different populations of P. antipodarum, suggesting that the Microphallus infecting P. estuarinus represent a distinct lineage. We also provide a promising set of candidate genes likely involved in parasitic infection and response to salinity stress.

  16. First paleoparasitological record of digenean eggs from a native deer from Patagonia Argentina (Cueva Parque Diana archaeological site).

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    María Ornela, Beltrame; Eleonor, Tietze; Alberto Enrique, Pérez; Norma Haydeé, Sardella

    2017-02-15

    Eggs representative of a digenean species were found in coprolites belonged to an endemic deer from Patagonia. Samples were collected from the archaeological site named "Cueva Parque Diana". This site is a cave located at the Lanín National Park, Neuquén Province, Argentina. The coprolites were dated from 2370±70 to 580±60 years B.P. The eggs were ellipsoidal, operculated, yellowish and thin-shelled. Measurements (n=65) ranged from 120.0 to 142.5 (133.2±6.53) μm long and 62.5 to 87.5 (72.6±6.15) μm wide. Eggs were well-preserved and were identified as belonged to Class Trematoda, Subclass Digenea, similar to those of Fasciola hepatica or with another species not identified at present from Patagonia. This is the first report of digenean eggs from ancient deer worldwide. The present study confirms the presence of representatives of digenean species in endemic deer from Patagonia in ancient times and the presence of a trematode disease prior to the arrival of European cattle.

  17. Do parasitic trematode cercariae demonstrate a preference for susceptible host species?

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    Brittany F Sears

    Full Text Available Many parasites are motile and exhibit behavioural preferences for certain host species. Because hosts can vary in their susceptibility to infections, parasites might benefit from preferentially detecting and infecting the most susceptible host, but this mechanistic hypothesis for host-choice has rarely been tested. We evaluated whether cercariae (larval trematode parasites prefer the most susceptible host species by simultaneously presenting cercariae with four species of tadpole hosts. Cercariae consistently preferred hosts in the following order: Anaxyrus ( = Bufo terrestris (southern toad, Hyla squirella (squirrel tree frog, Lithobates ( = Rana sphenocephala (southern leopard frog, and Osteopilus septentrionalis (Cuban tree frog. These host species varied in susceptibility to cercariae in an order similar to their attractiveness with a correlation that approached significance. Host attractiveness to parasites also varied consistently and significantly among individuals within a host species. If heritable, this individual-level host variation would represent the raw material upon which selection could act, which could promote a Red Queen "arms race" between host cues and parasite detection of those cues. If, in general, motile parasites prefer to infect the most susceptible host species, this phenomenon could explain aggregated distributions of parasites among hosts and contribute to parasite transmission rates and the evolution of virulence. Parasite preferences for hosts belie the common assumption of disease models that parasites seek and infect hosts at random.

  18. Using parasitic trematode larvae to quantify an elusive vertebrate host.

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    Byers, James E; Altman, Irit; Grosse, Andrew M; Huspeni, Todd C; Maerz, John C

    2011-02-01

    Digenean trematode parasites require multiple host species to complete their life cycles, and their abundance can often be strongly correlated with the abundance of their host species. Species richness and abundance of parasites in easily sampled host species may yield an accurate estimate of the species richness and abundance of other hosts in a parasite's life cycle that are difficult to survey directly. Accordingly, we investigated whether prevalence and mean abundance of trematodes could be used to estimate the abundance of one of their host species, diamondback terrapins (Malaclemys terrapin), which are difficult to sample and are designated as near threatened (by the International Union for Conservation of Nature [IUCN Red List]) along some U.S. coasts. As an adult the trematode Pleurogonius malaclemys is specific to terrapins. Its larval stages live first inside mud snails (Ilyanassa obsoleta) and are subsequently shed into the environment where they form external metacercarial cysts on hard surfaces such as snail opercula. The life cycle of P. malaclemys is completed when terrapins ingest these cysts. At 12 sites along the coast of Georgia (U.S.A.), we determined the prevalence of internal P. malaclemys larvae in mud snails (proportion of infected snails in a population) and the prevalence and mean abundance of external trematode cysts. We examined whether these data were correlated with terrapin abundance, which we estimated with mark-recapture methods. The abundance of external cysts and salinity explained ≥59% of the variability in terrapin abundance. We suggest that dependent linkages between the life stages of multihost parasites make them reliable predictors of host species' abundance, including hosts with abundances that are challenging to quantify directly.

  19. Phylogenetic analysis of parasitic trematodes of the genus Euclinostomum found in Trichopsis and Betta fish.

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    Senapin, S; Phiwsaiya, K; Laosinchai, P; Kowasupat, C; Ruenwongsa, P; Panijpan, B

    2014-06-01

    Many species of fish in the world are infected with digenean trematodes belonging to the genera Clinostomum and Euclinostomum. In this study, metacercariae, identified as Euclinostomum sp. on the basis of morphological characteristics and molecular data, were taken from 3 osphronemid fish- Trichopsis vittata , Trichopsis schalleri, and Betta imbellis, in Thailand. Phylogenetic analysis based on a mitochondrial gene (cytochrome c oxidase subunit I) and 2 nuclear genes (18S rDNA and ITS-internal transcribed spacer) of these Euclinostomum parasites indicated a clear distinction from those belonging to the Clinostomum genus. These are the first records of partial mitochondrial and nuclear DNA sequences of an Euclinostomum sp.

  20. Impact of trematode parasitism on the fauna of a North Sea tidal flat

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    Lauckner, G.

    1984-03-01

    The impact of larval trematodes on the fauna of a North Sea tidal flat is considered at the individual and at the population level, depicting the digenean parasites of the common periwinkle, Littorina littorea, and their life cycles, as an example. On the German North Sea coast, L. littorea is first intermediate host for 6 larval trematodes representing 6 digenean families — Cryptocotyle lingua (Heterophyidae), Himasthla elongata (Echinostomatidae), Renicola roscovita (Renicolidae), Microphallus pygmaeus (Microphallidae), Podocotyle atomon (Opecoelidae) and Cercaria lebouri (Notocotylidae). All except P. atomon utilize shore birds as final hosts; adult P. atomon parasitize in the intestine of teleosts, mainly pleuronectid flatfish. Second intermediate hosts of C. lingua are various species of fish; the cercariae of H. elongata encyst in molluscs and polychaetes, those of R. roscovita in molluscs; M. pygmaeus has an abbreviated life cycle; C. lebouri encysts free on solid surfaces; and the fish trematode P. atomon utilizes benthic crustaceans, mainly amphipods, as second intermediate hosts. On the tidal flats of the Königshafen (Sylt), up to 77% of the periwinkles have been found to be infested by larval trematodes. Maximum infestations in individual samples were 23% for C. lingua, 47% for H. elongata and 44% for R. roscovita. The digeneans cause complete ‘parasitic castration’ of their carriers and hence exclude a considerable proportion of the snails from the breeding population. Infestation reduces the longevity of affected hosts, and size-related, trematode-induced differential mortality causes changes in the normal size-frequency distribution of individual snail-age classes. Young flatfish Pleuronectes platessa from the Königshafen are 100% infested with metacercariae of C. lingua. Heavy infestation of the gills causes obstruction of blood vessels and respiratory impairment; metacercariae in the eyes and optic nerves cause visual and neurological

  1. Seasonal transmission of Opisthorchis viverrini sensu lato and a lecithodendriid trematode species in Bithynia siamensis goniomphalos snails in northeast Thailand.

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    Namsanor, Jutamas; Sithithaworn, Paiboon; Kopolrat, Kulthida; Kiatsopit, Nadda; Pitaksakulrat, Opal; Tesana, Smarn; Andrews, Ross H; Petney, Trevor N

    2015-07-01

    Seasonal changes play roles in the transmission success of fish-borne zoonotic trematodes (FZT). This study examined the seasonal transmission patterns of Opisthorchis viverrini sensu lato (s.l.) and a virgulate cercaria (family Lecithodendriidae) in the snail intermediate host, Bithynia siamensis goniomphalos in northeast Thailand. Snail samples were collected monthly during the rainy, cool, and hot seasons during 2012-2013 to determine the prevalence and intensity of larval trematode infections. The prevalence of O. viverrini s.l. varied significantly with season, being 0.31%, 1.05%, and 0.37% in the rainy, cool, and hot seasons, respectively (P < 0.05). Similarly, the prevalence of virgulate cercariae was 3.11%, 6.80%, and 1.64% in the rainy, cool, and hot seasons, respectively (P < 0.05). The intensity of larval trematode infections also varied between seasons and peaked in the hot season (P < 0.05) in both species. The snails infected with O. viverrini s.l. were significantly smaller (P < 0.05) and those infected with virgulate cercariae were significantly larger (P < 0.05) than uninfected snails. Seasonal variation and the different sizes of B. s. goniomphalos parasitized by O. viverrini s.l. and virgulate trematodes indicate complex host-parasite interactions with important implications for the epidemiology of O. viverrini s.l.

  2. Can parasites be indicators of free-living diversity? Relationships between species richness and the abundance of larval trematodes and of local benthos and fishes.

    Science.gov (United States)

    Hechinger, Ryan F; Lafferty, Kevin D; Huspeni, Todd C; Brooks, Andrew J; Kuris, Armand M

    2007-02-01

    Measuring biodiversity is difficult. This has led to efforts to seek taxa whose species richness correlates with the species richness of other taxa. Such indicator taxa could then reduce the time and cost of assessing the biodiversity of the more extensive community. The search for species richness correlations has yielded mixed results, however. This may be primarily because of the lack of functional relationships between the taxa studied. Trematode parasites are highly promising bioindicators. Diverse assemblages of larval trematode parasites are easily sampled in intermediate host snails. Through their life cycles these parasites are functionally coupled with the surrounding free-living diversity of vertebrate and invertebrate animals. It has been shown that larval trematodes in snails correlate positively with bird diversity and abundance. Here, we explore whether trematodes also correlate with standard measures of fishes, and large and small benthos, for 32 sites in three wetlands. We found associations between trematodes and benthic communities that were not consistent across wetlands. The associations were, however, consistently positive for large benthic species richness and density. Some of the contrasting associations between trematode and benthos may be explained by negative associations between large and small benthos. We found no associations with fish communities (probably because of the inadequacy of standard "snapshot" sampling methods for highly mobile fishes). The results support further exploration of trematodes as bioindicators of diversity and abundance of animal communities.

  3. Experimental infection of the digeneans to some congeneric snail species radiated in a single water system: Relative importance of local evolution and phylogenetic constraint.

    Science.gov (United States)

    Urabe, Misako

    2016-06-01

    To determine the relative importance of local adaptation caused by host-parasite coevolution and resource tracking by the parasites, the susceptibility of the freshwater snail genus Semisulcospira to the digenean parasite genus Genarchopsis was investigated experimentally. Four snail species endemic to the Lake Biwa system in Japan and two non-endemic species were investigated. All but one species was also tested for local variation in susceptibility. Parasites were obtained from Takashima (mix population of Genarchopsis gigi and Genarchopsis chubuensis) and Nagahama (G. chubuensis). In endemic Semisulcospira, closely related specie pairs (Semisulcospira habei and Semisulcospira niponica, Semisulcospira decipiens and Semisulcospira nakasekoae) showed similar susceptibilities to parasites from both localities. S. habei and S. niponica were highly susceptible to parasites from Takashima, but were resistant to parasites from Nagahama. S. decipiens and S. nakasekoae showed moderate susceptibility to parasites from both localities. None of the endemic snail species showed a clear local variation in susceptibility. These results show that the susceptibility of endemic Semisulcospira to Genarchopsis is conservative and can be regarded as an example of resource-tracking. One of the non-endemic snails, Semisulcospira libertina, showed local variation in susceptibility. This variation was not related to the sympatry of the parasites used for the experimental infection, suggesting that it was not the result of local adaptation by parasites.

  4. Host density increases parasite recruitment but decreases host risk in a snail-trematode system.

    Science.gov (United States)

    Buck, J C; Hechinger, R F; Wood, A C; Stewart, T E; Kuris, A M; Lafferty, K D

    2017-08-01

    Most species aggregate in local patches. High host density in patches increases contact rate between hosts and parasites, increasing parasite transmission success. At the same time, for environmentally transmitted parasites, high host density can decrease infection risk to individual hosts, because infective stages are divided among all hosts in a patch, leading to safety in numbers. We tested these predictions using the California horn snail, Cerithideopsis californica (=Cerithidea californica), which is the first intermediate host for at least 19 digenean trematode species in California estuaries. Snails become infected by ingesting trematode eggs or through penetration by free-swimming miracidia that hatch from trematode eggs deposited with final-host (bird or mammal) feces. This complex life cycle decouples infective-stage production from transmission, raising the possibility of an inverse relationship between host density and infection risk at local scales. In a field survey, higher snail density was associated with increased trematode (infected snail) density, but decreased trematode prevalence, consistent with either safety in numbers, parasitic castration, or both. To determine the extent to which safety in numbers drove the negative snail-density-trematode-prevalence association, we manipulated uninfected snail density in 83 cages at eight sites within Carpinteria Salt Marsh (California, USA). At each site, we quantified snail density and used data on final-host (bird and raccoon) distributions to control for between-site variation in infective-stage supply. After three months, overall trematode infections per cage increased with snail biomass density. For egg-transmitted trematodes, per-snail infection risk decreased with snail biomass density in the cage and surrounding area, whereas per-snail infection risk did not decrease for miracidium-transmitted trematodes. Furthermore, both trematode recruitment and infection risk increased with infective

  5. Host density increases parasite recruitment but decreases host risk in a snail-trematode system

    Science.gov (United States)

    Buck, Julia C; Hechinger, R.F.; Wood, A.C.; Stewart, T.E.; Kuris, A.M.; Lafferty, Kevin D.

    2017-01-01

    Most species aggregate in local patches. High host density in patches increases contact rate between hosts and parasites, increasing parasite transmission success. At the same time, for environmentally-transmitted parasites, high host density can decrease infection risk to individual hosts, because infective stages are divided among all hosts in a patch, leading to safety in numbers. We tested these predictions using the California horn snail, Cerithideopsis californica (=Cerithidea californica), which is the first intermediate host for at least 19 digenean trematode species in California estuaries. Snails become infected by ingesting trematode eggs or through penetration by free-swimming miracidia that hatch from trematode eggs deposited with final-host (bird or mammal) feces. This complex life cycle decouples infective-stage production from transmission, raising the possibility of an inverse relationship between host density and infection risk. In a field survey, higher snail density was associated with increased trematode (infected snail) density, but decreased trematode prevalence, consistent with either safety in numbers, parasitic castration, or both. To determine the extent to which safety in numbers drove the negative snail density-trematode prevalence association, we manipulated uninfected snail density in 83 cages at eight sites within Carpinteria Salt Marsh (CA, USA). At each site, we quantified snail density and used data on final-host (bird and raccoon) distributions to control for between-site variation in infective-stage supply. After three months, overall trematode infections per cage increased with snail-biomass density. For egg-transmitted trematodes, per-snail infection risk decreased with snail-biomass density in the cage and surrounding area, whereas per-snail infection risk did not decrease for miracidium-transmitted trematodes. Furthermore, both trematode recruitment and infection risk increased with infective-stage input, but this was

  6. Low genetic diversity in wide-spread Eurasian liver fluke Opisthorchis felineus suggests special demographic history of this trematode species.

    Science.gov (United States)

    Brusentsov, Ilja I; Katokhin, Alexey V; Brusentsova, Irina V; Shekhovtsov, Sergei V; Borovikov, Sergei N; Goncharenko, Grigoriy G; Lider, Lyudmila A; Romashov, Boris V; Rusinek, Olga T; Shibitov, Samat K; Suleymanov, Marat M; Yevtushenko, Andrey V; Mordvinov, Viatcheslav A

    2013-01-01

    Opisthorchis felineus or Siberian liver fluke is a trematode parasite (Opisthorchiidae) that infects the hepato-biliary system of humans and other mammals. Despite its public health significance, this wide-spread Eurasian species is one of the most poorly studied human liver flukes and nothing is known about its population genetic structure and demographic history. In this paper, we attempt to fill this gap for the first time and to explore the genetic diversity in O. felineus populations from Eastern Europe (Ukraine, European part of Russia), Northern Asia (Siberia) and Central Asia (Northern Kazakhstan). Analysis of marker DNA fragments from O. felineus mitochondrial cytochrome c oxidase subunit 1 and 3 (cox1, cox3) and nuclear rDNA internal transcribed spacer 1 (ITS1) sequences revealed that genetic diversity is very low across the large geographic range of this species. Microevolutionary processes in populations of trematodes may well be influenced by their peculiar biology. Nevertheless, we suggest that lack of population genetics structure observed in O. felineus can be primarily explained by the Pleistocene glacial events and subsequent sudden population growth from a very limited group of founders. Rapid range expansion of O. felineus through Asian and European territories after severe bottleneck points to a high dispersal potential of this trematode species.

  7. Low genetic diversity in wide-spread Eurasian liver fluke Opisthorchis felineus suggests special demographic history of this trematode species.

    Directory of Open Access Journals (Sweden)

    Ilja I Brusentsov

    Full Text Available Opisthorchis felineus or Siberian liver fluke is a trematode parasite (Opisthorchiidae that infects the hepato-biliary system of humans and other mammals. Despite its public health significance, this wide-spread Eurasian species is one of the most poorly studied human liver flukes and nothing is known about its population genetic structure and demographic history. In this paper, we attempt to fill this gap for the first time and to explore the genetic diversity in O. felineus populations from Eastern Europe (Ukraine, European part of Russia, Northern Asia (Siberia and Central Asia (Northern Kazakhstan. Analysis of marker DNA fragments from O. felineus mitochondrial cytochrome c oxidase subunit 1 and 3 (cox1, cox3 and nuclear rDNA internal transcribed spacer 1 (ITS1 sequences revealed that genetic diversity is very low across the large geographic range of this species. Microevolutionary processes in populations of trematodes may well be influenced by their peculiar biology. Nevertheless, we suggest that lack of population genetics structure observed in O. felineus can be primarily explained by the Pleistocene glacial events and subsequent sudden population growth from a very limited group of founders. Rapid range expansion of O. felineus through Asian and European territories after severe bottleneck points to a high dispersal potential of this trematode species.

  8. Molecular Cytogenetics in Digenean Parasites: Linked and Unlinked Major and 5S rDNAs, B Chromosomes and Karyotype Diversification.

    Science.gov (United States)

    García-Souto, Daniel; Pasantes, Juan J

    2015-01-01

    Digenetic trematodes are the largest group of internal metazoan parasites, but their chromosomes are poorly studied. Although chromosome numbers and/or karyotypes are known for about 300 of the 18,000 described species, molecular cytogenetic knowledge is mostly limited to the mapping of telomeric sequences and/or of major rDNA clusters in 9 species. In this work we mapped major and 5S rDNA clusters and telomeric sequences in chromosomes of Bucephalus minimus, B. australis, Prosorhynchoides carvajali (Bucephaloidea), Monascus filiformis (Gymnophalloidea), Parorchis acanthus (Echinostomatoidea), Cryptocotyle lingua (Opisthorchioidea), Cercaria longicaudata, Monorchis parvus (Monorchioidea), Diphterostomum brusinae, and Bacciger bacciger (Microphalloidea). Whilst single major and minor rDNA clusters were mapped to different chromosome pairs in B. minimus and P. acanthus, overlapping signals were detected on a single chromosome pair in the remaining taxa. FISH experiments using major rDNA and telomeric probes clearly demonstrated the presence of highly stretched NORs in most of the digenean taxa analyzed. B chromosomes were detected in the B. bacciger samples hosted by Ruditapes decussatus. Although the cercariae specimens obtained from Donax trunculus, Tellina tenuis, and R. decussatus were in agreement with B. bacciger, their karyotypes showed striking morphological differences in agreement with the proposed assignation of these cercariae to different species of the genus Bacciger. Results are discussed in comparison with previous data on digenean chromosomes. © 2015 S. Karger AG, Basel.

  9. Digenean parasites of the marine gastropods Littorina littorea and Gibbula umbilicalis in the Northern Portuguese Atlantic coast, with a review of digeneans infecting the two gastropod genera

    Directory of Open Access Journals (Sweden)

    Graça Costa

    2016-05-01

    Full Text Available Objective: To study the digenean parasites of the prosobranch gastropods, Littorina littorea (L. littorea and Gibbula umbilicalis (G. umbilicalis from rocky shores of the Northern Atlantic coast of Portugal. Methods: A total of 413 L. littorea and 2603 G. umbilicalis were collected from rocky shores, at Aveiro estuary, Aguda Beach, and Foz Beach at Porto (Northern Atlantic coast of Portugal from January to July 2014 and February 2014 to January 2015, respectively. Gonads and digestive glands of the gastropods were examined under light microscopy for the presence of digeneans. Infected gonads of L. littorea were prepared for histological observation, whereas digeneans found in G. umbilicalis were studied and identified with the aid of light and scanning electron microscopy. Results: Two species of digeneans were found infecting the digestive gland and gonads of G. umbilicalis, namely, Cainocreadium labracis and Lecithochirium furcolabiatum with a combined prevalence of 3%. Histological observations of gonads of L. littorea revealed the infection with digeneans, with considerable replacement of gonadal tissues. These digeneans were not identified to species level. The prevalence of digeneans in this snail host was 0.7%. Conclusions: The present study adds G. umbilicalis as another first intermediate host for Cainocreadium labracis and extends its geographical range to the Portuguese Atlantic coast. Cercariae of Lecithochirium furcolabiatum were previously reported from G. umbilicalis. A literature review of digeneans occurring in the gastropod genera Gibbula and Littorina is given.

  10. Social Organization in Parasitic Flatworms--Four Additional Echinostomoid Trematodes Have a Soldier Caste and One Does Not.

    Science.gov (United States)

    Garcia-Vedrenne, Ana E; Quintana, Anastasia C E; DeRogatis, Andrea M; Martyn, Kayla; Kuris, Armand M; Hechinger, Ryan F

    2016-02-01

    Complex societies where individuals exhibit division of labor with physical polymorphism, behavioral specialization, and caste formation have evolved several times throughout the animal kingdom. Recently, such complex sociality has been recognized in digenean trematodes; evidence is limited to 6 marine species. Hence, the extent to which a soldier caste is present throughout the Trematoda is sparsely documented, and there are no studies detailing the structure of a species lacking such a social structure. Here we examine colony structure for an additional 5 echinostomoid species, 4 of which infect the marine snail Cerithidea californica and 1 (Echinostoma liei) that infects the freshwater snail Biomphalaria glabrata . For all species, we present redia morphology (pharynx and body size) and the distribution of individuals of different castes throughout the snail body. When morphological evidence indicated the presence of a soldier caste, we assessed behavior by measuring attack rates of the different morphs toward heterospecific trematodes. Our findings indicate that each of the 4 species from C. californica have a permanent soldier caste while E. liei does not. The observed intra- and inter-specific variation of caste structure for those species with soldiers, and the documentation of colony structure for a species explicitly lacking permanent soldiers, emphasizes the diverse nature of trematode sociality and the promise of the group to permit comparative investigations of the evolution and ecology of sociality.

  11. Helminths of Wild Predatory Mammals (Mammalia, Carnivora of Ukraine. Trematodes

    Directory of Open Access Journals (Sweden)

    Korol E. N.

    2016-08-01

    Full Text Available The paper summarises information on 11 species of trematodes parasitic in 9 species of wild carnivorans of Ukraine. The largest number of trematode species (9 was found in the red fox (Vulpes vulpes. Alaria alata (Diplostomidae appeared to be the most common trematode parasite in the studied group; it was found in 4 host species from 9 administrative regions and Crimea.

  12. Can parasites be indicators of free-living diversity? Relationships between the species richness and abundance of larval trematodes with that of local fishes and benthos

    OpenAIRE

    Hechinger, Ryan F.; Lafferty, K D; Huspeni, T C; A. J. Brooks; Kuris, A M

    2007-01-01

    Measuring biodiversity is difficult. This has spawned efforts to seek taxa whose species richness correlates with the species richness of other taxa. Such indicator taxa could then reduce the time and cost of assessing the biodiversity of the more extensive community. However, the search for species richness correlations has yielded mixed results. This may primarily be due to the lack of functional relationships between the taxa studied. Trematode parasites are highly promising bioindica...

  13. Digenean parasites of six species of birds from Formosa Province, Argentina Digéneos parásitos de seis especies de aves de la provincia de Formosa, Argentina

    Directory of Open Access Journals (Sweden)

    Lía Inés Lunaschi

    2009-04-01

    Full Text Available The aim of this paper is to increase the knowledge of the diversity of digenean parasites from birds collected in Formosa Province, Argentina. The helminthological survey of 15 specimens of 6 bird species revealed the presence of 5 digenean species: Clinostomatopsis sorbens (Braun, 1899 and Clinostomum marginatum (Rudolphi, 1819 (Clinostomidae from the esophagus of Tigrisoma lineatum (Boddaert; Glaphyrostomum propinquum Braun, 1901 (Brachylaimidae from the cloaca of Guira guira (Gmelin; Stomylotrema vicarium Braun, 1901 (Stomylotrematidae from the cloaca of Busarellus nigricollis (Latham and Buteogallus meridionalis (Latham; and Athesmia heterolecithodes (Braun, 1899 (Dicrocoeliidae from the bile canaliculi of G. guira, Milvago chimachima (Vieillot and Rostrhamus sociabilis (Vieillot. The present study adds new morphometric data on 2 species of digeneans (C. sorbens and G. propinquum and new host records for C. sorbens, G. propinquum, A. heterolecithodes and S. vicarium. The genera Clinostomatopsis Dollfus, 1932 and Glaphyrostomum Braun, 1901 are reported for the first time in Argentina.El propósito de este trabajo es incrementar el conocimiento sobre la diversidad de digéneos parásitos de aves recolectadas en la provincia de Formosa, Argentina. El estudio helmintológico de 15 ejemplares de 6 especies de aves reveló la presencia de 5 especies de digéneos: Clinostomatopsis sorbens (Braun, 1899 y Clinostomum marginatum (Rudolphi, 1819 (Clinostomidae halladas en el esófago de Tigrisoma lineatum (Boddaert; Glaphyrostomum propinquum Braun, 1901 (Brachylaimidae recolectada de la cloaca de Guira guira (Gmelin; Stomylotrema vicarium Braun, 1901 (Stomylotrematidae encontrada en la cloaca de Busarellus nigricollis (Latham y Buteogallus meridionalis (Latham; Athesmia heterolecithodes (Braun, 1899 (Dicrocoeliidae hallada en los canalículos biliares de G. guira, Milvago chimachima (Vieillot y Rostrhamus sociabilis (Vieillot. El presente estudio

  14. Feeding behavior of black carp Mylopharyngodon piceus (Pisces: Cyprinidae) on fry of other fish species and trematode transmitting snail species

    DEFF Research Database (Denmark)

    Hung, Nguyen Manh; The, Dang Tat; Stauffer, Jay R.

    2014-01-01

    Fish raised in aquaculture ponds may get infected with fishborne zoonotic trematodes (FZT) during the nursing stage. Freshwater snails serve as intermediate hosts for FZT and we wanted to explore the possibility of controlling snails by stocking nursery ponds with a few juvenile specimens...... offered snails as food; the odds of survival of fry from tanks with medium sized and large black carp was 5.6% and 39.9%, respectively of that of fry in tanks with small sized black carp. Since the large black carp also consumed fewer snails than medium sized fish, we believe that large specimens were...... stressed in the experimental aquaria. Under semi-field conditions, presence of the black carp had no effect on survival of fry of Oreochromis niloticus and C. carpio both in the absence and presence of snails as alternative food. The black carp consumed most snails offered with the exception of some...

  15. Different Host Exploitation Strategies in Two Zebra Mussel-Trematode Systems: Adjustments of Host Life History Traits

    OpenAIRE

    Laëtitia Minguez; Thierry Buronfosse; Laure Giambérini

    2012-01-01

    The zebra mussel is the intermediate host for two digenean trematodes, Phyllodistomum folium and Bucephalus polymorphus, infecting gills and the gonad respectively. Many gray areas exist relating to the host physiological disturbances associated with these infections, and the strategies used by these parasites to exploit their host without killing it. The aim of this study was to examine the host exploitation strategies of these trematodes and the associated host physiological disturbances. W...

  16. Multilocus sequence evaluation for differentiating species of the trematode Family Gastrothylacidae, with a note on the utility of mitochondrial COI motifs in species identification.

    Science.gov (United States)

    Ghatani, Sudeep; Shylla, Jollin Andrea; Roy, Bishnupada; Tandon, Veena

    2014-09-15

    Amphistomiasis, a neglected trematode infectious disease of ruminants, is caused by numerous species of amphistomes belonging to six families under the Superfamily Paramphistomoidea. In the present study, four frequently used DNA markers, viz. nuclear ribosomal 28S (D1-D3 regions), 18S and ITS2 and mitochondrial COI genes, as well as sequence motifs from these genes were evaluated for their utility in species characterization of members of the amphistomes' Family Gastrothylacidae commonly prevailing in Northeast India. In sequence and phylogenetic analyses the COI gene turned out to be the most useful marker in identifying the gastrothylacid species, with the exception of Gastrothylax crumenifer, which showed a high degree of intraspecific variations among its isolates. The sequence analysis data also showed the ITS2 region to be effective for interspecies characterization, though the 28S and 18S genes were found unsuitable for the purpose. On the other hand, sequence motif analysis data revealed the motifs from the COI gene to be highly conserved and specific for their target species which allowed accurate in silico identification of the gastrothylacid species irrespective of their intraspecific differences. We propose the use of COI motifs generated in the study as a potential tool for identification of these species.

  17. Digenean parasites of the marine gastropodsLittorina littorea andGibbula umbilicalis in the Northern Portuguese Atlantic coast, with a review of digeneans infecting the two gastropod genera

    Institute of Scientific and Technical Information of China (English)

    Graa Costa; Snia Soares; Fernando Carvalho; Joo Bela

    2016-01-01

    Objective:To study the digenean parasites of the prosobranch gastropods,Littorina littorea(L. littorea) andGibbula umbilicalis (G. umbilicalis) from rocky shores of the Northern Atlantic coast of Portugal. Methods: A total of 413L. littorea and 2 603G. umbilicalis were collected from rocky shores, at Aveiro estuary, Aguda Beach, and Foz Beach at Porto (Northern Atlantic coast of Portugal) from January to July 2014 and February 2014 to January 2015, respectively. Gonads and digestive glands of the gastropods were examined under light microscopy for the presence of digeneans. Infected gonads ofL. littorea were prepared for histological observation, whereas digeneans found in G. umbilicalis were studied and identified with the aid of light and scanning electron microscopy. Results: Two species of digeneans were found infecting the digestive gland and gonads of G. umbilicalis, namely,Cainocreadium labracis andLecithochirium furcolabiatum with a combined prevalence of 3%. Histological observations of gonads ofL. littorearevealed the infection with digeneans, with considerable replacement of gonadal tissues. These digeneans were not identified to species level. The prevalence of digeneans in this snail host was 0.7%. Conclusions: The present study addsG. umbilicalis as another first intermediate host for Cainocreadium labracis and extends its geographical range to the Portuguese Atlantic coast. Cercariae ofLecithochirium furcolabiatum were previously reported fromG. umbilicalis. A literature review of digeneans occurring in the gastropod generaGibbulaandLittorina is given.

  18. Surface topography of two trematodes parasites infecting grey heron Ardea cinerea Jouyi (Aves, Ciconiiformes) in Qena, Egypt.

    Science.gov (United States)

    Ammar, Khalaf Nour Abd El-Wahed

    2015-04-01

    Apharyngostrigea ardeolina and Echinoparyphium recurvatum are two important digenean parasites that were recovered from small intestine of grey heron with an infection rate (16.2%) and (8.8%) respectively. The surface topography of two species was redescribed by both light and scanning electron microscopy. Using SEM studies showed that the body surface of two trematodes were covered by contact receptors, several types of sensory tegumental papillae which may have useful function in orientation and feeding through increasing the surface area of absorption, could also play a role in sensation or in selection of the materials for ingestion by the fluke. The head collar of E. recurvatum is reniform in shape, bearing uninterrupted double row of 41 collar finger-like spines, a total including 4 end group ones on both ventral corners., tegumental spines were tongue-shaped without a terminal tip.

  19. Larval trematodes (Digenea of the great pond snail, Lymnaea stagnalis (L., (Gastropoda, Pulmonata in Central Europe: a survey of species and key to their identification

    Directory of Open Access Journals (Sweden)

    Faltýnková A.

    2007-03-01

    Full Text Available A survey of cercariae and metacercariae (Trematoda, Digenea from the great pond snail (Lymnaea stagnalis in Central Europe (Austria, Czech Republic, South-East Germany, Poland and Slovak Republic is presented, based on a study of 3,628 snails examined from 1998 to 2005. A total of 953 (26.3% L. stagnalis were infected with 24 trematode species comprising 19 species of cercariae and 11 species of metacercariae (six species occurred both as cercarie and metacercarie of eight families. The dominant cercariae were those of Opisthioglyphe ranae (159 hosts infected, Plagiorchis elegans (141 (both family Plagiorchiidae and Echinoparyphium aconiatum (153 (Echinostomatidae; 14 double infections were found. The most frequent metacercariae were those of Neoglyphe locellus (71 (Omphalometridae, E. aconiatum (66, Echinostoma sp. (59 and Moliniella anceps (48 (Echinostomatidae. In the previous studies carried out in Central Europe, a very similar spectrum of nine trematode families of 22 cercariae determined to species level and 43 types of cercariae reported under generic or provisional names, which can be in many cases conspecific with the previous taxa, were found. A simple key to identification of cercariae and metacercariae, together with their illustrations, is provided.

  20. Monorchiid trematodes of the painted sweetlips, Diagramma labiosum (Perciformes: Haemulidae), from the southern Great Barrier Reef, including a new genus and three new species.

    Science.gov (United States)

    Searle, Emily L; Cutmore, Scott C; Cribb, Thomas H

    2014-07-01

    Five monorchiid species are reported from Diagramma labiosum Macleay (Perciformes: Haemulidae) collected from Heron Island on the southern Great Barrier Reef (GBR): two described species, Helicometroides longicollis Yamaguti, 1934 and Diplomonorchis kureh Machida, 2005 and three new species, including one new genus, Asymmetrostoma heronensis n. g., n. sp., Lasiotocus arrhichostoma n. sp. and Proctotrema addisoni n. sp. Helicometroides longicollis and D. kureh were previously reported from the closely related species Diagramma pictum (Thunberg) from Japan. Two further monorchiid species known from D. pictum, Genolopa plectorhynchi (Yamaguti, 1934) and Paraproctotrema fusiforme Yamaguti, 1934, appear to be absent from the southern Great Barrier Reef. Previous reports of two other monorchiids from D. labiosum from the GBR, Paramonorcheides pseudocaranxi Dove & Cribb, 1998 and Helicometroides vitellosus (Durio & Manter, 1968), are shown to have been made in error. The high richness of monorchiids and other trematode families in D. labiosum is consistent with that seen in other haemulids elsewhere.

  1. Different host exploitation strategies in two zebra mussel-trematode systems: adjustments of host life history traits.

    Science.gov (United States)

    Minguez, Laëtitia; Buronfosse, Thierry; Giambérini, Laure

    2012-01-01

    The zebra mussel is the intermediate host for two digenean trematodes, Phyllodistomum folium and Bucephalus polymorphus, infecting gills and the gonad respectively. Many gray areas exist relating to the host physiological disturbances associated with these infections, and the strategies used by these parasites to exploit their host without killing it. The aim of this study was to examine the host exploitation strategies of these trematodes and the associated host physiological disturbances. We hypothesized that these two parasite species, by infecting two different organs (gills or gonads), do not induce the same physiological changes. Four cellular responses (lysosomal and peroxisomal defence systems, lipidic peroxidation and lipidic reserves) in the host digestive gland were studied by histochemistry and stereology, as well as the energetic reserves available in gonads. Moreover, two indices were calculated related to the reproductive status and the physiological condition of the organisms. Both parasites induced adjustments of zebra mussel life history traits. The host-exploitation strategy adopted by P. folium would occur during a short-term period due to gill deformation, and could be defined as "virulent." Moreover, this parasite had significant host gender-dependent effects: infected males displayed a slowed-down metabolism and energetic reserves more allocated to growth, whereas females displayed better defences and would allocate more energy to reproduction and maintenance. In contrast, B. polymorphus would be a more "prudent" parasite, exploiting its host during a long-term period through the consumption of reserves allocated to reproduction.

  2. Different host exploitation strategies in two zebra mussel-trematode systems: adjustments of host life history traits.

    Directory of Open Access Journals (Sweden)

    Laëtitia Minguez

    Full Text Available The zebra mussel is the intermediate host for two digenean trematodes, Phyllodistomum folium and Bucephalus polymorphus, infecting gills and the gonad respectively. Many gray areas exist relating to the host physiological disturbances associated with these infections, and the strategies used by these parasites to exploit their host without killing it. The aim of this study was to examine the host exploitation strategies of these trematodes and the associated host physiological disturbances. We hypothesized that these two parasite species, by infecting two different organs (gills or gonads, do not induce the same physiological changes. Four cellular responses (lysosomal and peroxisomal defence systems, lipidic peroxidation and lipidic reserves in the host digestive gland were studied by histochemistry and stereology, as well as the energetic reserves available in gonads. Moreover, two indices were calculated related to the reproductive status and the physiological condition of the organisms. Both parasites induced adjustments of zebra mussel life history traits. The host-exploitation strategy adopted by P. folium would occur during a short-term period due to gill deformation, and could be defined as "virulent." Moreover, this parasite had significant host gender-dependent effects: infected males displayed a slowed-down metabolism and energetic reserves more allocated to growth, whereas females displayed better defences and would allocate more energy to reproduction and maintenance. In contrast, B. polymorphus would be a more "prudent" parasite, exploiting its host during a long-term period through the consumption of reserves allocated to reproduction.

  3. Feeding behavior of black carp Mylopharyngodon piceus (Pisces: Cyprinidae) on fry of other fish species and trematode transmitting snail species

    DEFF Research Database (Denmark)

    Hung, Nguyen Manh; The, Dang Tat; Stauffer, Jay R.

    2014-01-01

    Fish raised in aquaculture ponds may get infected with fishborne zoonotic trematodes (FZT) during the nursing stage. Freshwater snails serve as intermediate hosts for FZT and we wanted to explore the possibility of controlling snails by stocking nursery ponds with a few juvenile specimens...

  4. Trematode Centrocestus formosanus infection and distribution in ornamental fishes in Mexico.

    Science.gov (United States)

    Ortega, César; Fajardo, Raúl; Enríquez, Ricardo

    2009-03-01

    The aim of this study was to determine the ornamental fish species affected by the metacercariae of the digenean trematode Centrocestus formosanus and its distribution in 48 fish farms in Morelos, central Mexico. The parasite was found to form various numbers of branchial cysts in 11 of the 25 species analyzed. Goldfish Carassius auratus was the most commonly affected species; 20 of 30 farms were positive for this parasite, the fish showing severe clinical signs and having a high mortality rate. For the first time in the region, koi (a variant of common carp Cyprinus carpio), zebrafish Danio rerio, suckermouth catfish Hypostomus plecostomus and blue gourami Trichogaster trichopterus (also known as the threespot gourami) were positive; meanwhile, Mexican tetra Astyanax mexicanus, which had previously been reported positive in other studies in this region, was found to be negative. The parasite was observed in fish from 27 of the 48 farms studied. Ten of 15 municipalities had farms that were positive for the parasite. These results suggest that the distribution of C. formosanus is closely related to the use of water that had been contaminated with the parasite and to the presence of a snail, the red-rimmed melania Melanoides tuberculata.

  5. Morphometric and molecular analyses of two digenean species from the mullet: Haplosplanchnus pachysomus (Eysenhardt, 1892) from Vietnam and Provitellotrema crenimugilis Pan, 1984 from the Russian southern Far East.

    Science.gov (United States)

    Besprozvannykh, V V; Atopkin, D M; Ngo, H D; Ermolenko, A V; Ha, N V; Tang, N V; Beloded, A Yu

    2016-03-01

    Adults of Haplosplanchnus pachysomus (Eysenhardt, 1829) were found in the intestine of Liza engeli (Bleeker) from the coastal waters of Cat Ba Island, Ha Long Bay, northern Vietnam. Additionally, Provitellotrema crenimugilis Pan, 1984 was discovered in Liza haematocheila (Temminck & Schlegel) from Vostok Bay, Gulf of Peter the Great, southern Far-East Russia. Data concerning morphology, 18S rDNA and 28S rDNA of these worms were obtained.The molecular data confirmed the validity of these species and showed that specimens identified as H. pachysomus are closely related to specimens of H. pachysomus found in Spain, and that P. crenimugilis is closely related to Haplosplanchnus purii. Molecular differentiation of P. crenimugilis and H. purii was 0.92% by combined ribosomal gene sequences that confirmed species validity. Molecular differentiation between P. crenimugilis and H. purii, on the one hand, and H. pachysomus, on the other hand, was much higher, suggesting that the sequence for H. purii in GenBank is for a misidentified species of the genus Provitellotrema Pan, 1984.

  6. EKOLOGICAL-FAUNAL ANALYSES OF THE TREMATODES OF WATER-MARSH BIRDS OF THE TRANSBOUNDARY JANDAN LAKE

    Directory of Open Access Journals (Sweden)

    Y. A. Mahmudova

    2013-01-01

    Full Text Available In 2000-08 in the Jandar Lake, which is situated on the territories of Azerbaijan and Georgia, the author studied waterfowls of 23 species and found 35 species of trematodes. Trematode fauna was richer in birds with a wider range of food and bigger sizes, obligate ichthyophagous birds were infected with trematode more than birds, which rarely eating fish. Among the found trematodes 4 species are dangerous to birds, 3 species – to fish, and 3 species to human.

  7. Evaluating the Biological and Ecological Factors Influencing Transmission of Larval Digenetic Trematodes: A Test of Second Intermediate Host Specificity of Two North American Halipegus Species.

    Science.gov (United States)

    Stigge, Heather A; Bolek, Matthew G

    2016-12-01

    Host specificity of parasites is a basic principle in parasitology; however, it is not easily measured. Previously, host specificity was calculated as the number of species that a parasite infected, but this is not an accurate description of host usage because some species are capable of being infected but do not contribute to the completion of the life cycle. Instead, measures of host specificity should take into consideration interactions between a parasite and a potential host species as well as interactions between current and subsequent hosts in the life cycle. The objectives of this study were to track the development of 2 trematode species, Halipegus eccentricus and Halipegus occidualis , in 3 phylogenetically and ecologically distinct microcrustacean second intermediate hosts, and then evaluate the extent to which each of these hosts contributed to transmission of each Halipegus species to the next odonate host in the life cycle. All 3 microcrustacean species exposed became infected with both species of Halipegus. The patterns of growth of H. eccentricus and H. occidualis were similar, but there were consistent differences in the rates of growth among the microcrustacean species in both Halipegus species. Regardless of host species infected, all individuals of both species were considered to be developmentally infective to the next host in the life cycle by 19 days postexposure (DPE) when they lost their excretory bladder. Worms of varying sizes were capable of surviving without this structure, suggesting that there is not a strong relationship between the rate of growth of the metacercariae and the development of their osmoregulatory system. Although Halipegus species were capable of living without an excretory bladder at 19 DPE, there were differences in their size and rates at which the 3 microcrustaceans contributed to transmission of the parasites to subsequent odonate hosts. Collectively, under controlled laboratory conditions, there was an

  8. Digenean larvae parasitizing Ruditapes decussatus (Bivalvia from Tunisianan coasts

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    Dhrif E.

    2015-06-01

    Full Text Available Eleven species of trematode larvae (sporocysts and cercariae of Bucephalus labracis Paggi et Orecchia, 1965 and Cercaria lata Lespes, 1857 and metacercariae of Acanthoparyphium sp. Dietz , 1909, Caecincola parvulus Marshall et Gilbert, 1905, Curtuteria australis Allison, 1979, Gymnophallus fossarum Bartoli, 1965, Gymnophallus rebecqui Bartoli, 1983, Lepocreadium pegorchis Stossich, 1901, Parazoogonus sp. Looss, 1901, Psilostomum brevicolle Creplin, 1829 and Robphildollfusium fractum Rudolphi, 1819 were found in the clam (Ruditapes decussatus from Tunisian coasts. A part from B. labracis and Cercaria lata, the other trematode species were recorded for the first time in Tunisia. The examination of the frequency of recorded parasites reveals some monthly variation. This variation is statistically significant by comparing the sampling sites. These results indicate that more frequent parasites (G. fossarum, Cercaria lata, Curtuteria australis and Acanthoparyphium sp. could be considered as biological indicators making it possible to predict the capture localities of the clams.

  9. A new genus and a new species of Cladorchiidae (Digenea: Dadayiinae) from Podocnemis expansa (Chelonia) of the neotropical region, State of Pará, Brazil.

    Science.gov (United States)

    Knoff, Marcelo; Brooks, Daniel Rusk; Mullins, Maria Cristina; Gomes, Delir Corrêa

    2012-04-01

    A new species of amphistome digenean from the stomach and intestine of Podocnemis expansa (Pelomedusidae), of the tropical rain forest, from the State of Pará, Brazil, is described and allocated to a new genus ( Oriximinatrema noronhae ). The new species is characterized by the presence of an esophageal bulb, an esophageal extension uncovered by an extension of the pharyngeal sacs, a well-developed cirrus sac, post-bifurcal genital sucker, a ventro-terminal acetabulum with an anterior lip, and medium-sized eggs. This is the first report of a Dadayiinae trematode infecting a reptilian host.

  10. Evidence of a species complex within the food-borne trematode Opisthorchis viverrini and possible co-evolution with their first intermediate hosts.

    Science.gov (United States)

    Saijuntha, Weerachai; Sithithaworn, Paiboon; Wongkham, Sopit; Laha, Thewarach; Pipitgool, Vichit; Tesana, Smarn; Chilton, Neil B; Petney, Trevor N; Andrews, Ross H

    2007-05-01

    The food-borne trematodes, Opisthorchis viverrini, O. felineus and Clonorchis sinensis, have long been recognized as the cause of major human health problems, with an estimated 40 million infected persons. Of the three species of liver fluke, only O. viverrini is classified as a type 1 carcinogen because of its role as an initiator of chronic inflammation and the subsequent development of cholangiocarcinoma. At present, there are no techniques for the early diagnosis of cholangiocarcinoma and it is fatal for most patients. There is considerable variation in parasite prevalence and disease presentation in different geographical areas, the latter of which may be associated with genetic differences among parasites. In the present study, multilocus enzyme electrophoresis was used to provide a comprehensive genetic characterization of O. viverrini from different geographical localities in Thailand and the Peoples' Democratic Republic of Laos. Parasites from different localities were compared genetically at 32 enzyme loci. The results of the genetic analyses are sufficient to reject the null hypothesis that O. viverrini represents a single species. Therefore, O. viverrini consists of at least two genetically distinct, yet morphologically similar (i.e. cryptic) species. Moreover, there was also separation of the different populations of snails (i.e. the first intermediate hosts) into two distinct genetic groups that corresponded with the delineation of O. viverrini into two species. This suggests that there may be a history of co-evolution in this host-parasite lineage. Additionally, five distinct genetic groups of parasites were detected, each of which occurred within a different and independent river wetland system. Our findings have major implications for the implementation of effective control and surveillance programs targeted to these medically important food-borne parasites.

  11. Gastrointestinal digeneans (Platyhelminthes: Trematoda of horseshoe and vesper bats (Chiroptera: Rhinolophidae and Vespertilionidae in Serbia

    Directory of Open Access Journals (Sweden)

    Horvat Ž.

    2017-03-01

    Full Text Available The qualitative and quantitative analyses of the digenean fauna of bats were conducted for the first time in Serbia. The sample comprised of 118 individuals of 12 bat species (Rhinolophus ferrumequinum, Myotis mystacinus, M. alcathoe, M. brandtii, M. oxygnathus, M. myotis, Hypsugo savii, Pipistrellus pipistrellus, P. nathusii, Plecotus auritus, P. austriacus and Nyctalus noctula collected from 15 sites throughout Serbia. Six digenean species were identified: Lecithodendrium linstowi, Plagiorchis sp., Prosthodendrium longiforme, P. chilostomum, P. parvouterus and Mesotretes peregrinus. The helminths were recorded from 35 individual hosts (29.7 %. The species Lecithodendrium linstowi infected the highest percentage of hosts (19.5 %, with a mean abundance of 4.6. GLM analysis of exploratory factors showed that host species and host sex had a significant influence on parasite load, while locality and host age did not influence parasite abundance. No evidence of zoonotic species was found.

  12. Large scale screening of digeneans for Neorickettsia endosymbionts using real-time PCR reveals new Neorickettsia genotypes, host associations and geographic records.

    Directory of Open Access Journals (Sweden)

    Stephen E Greiman

    Full Text Available Digeneans are endoparasitic flatworms with complex life cycles including one or two intermediate hosts (first of which is always a mollusk and a vertebrate definitive host. Digeneans may harbor intracellular endosymbiotic bacteria belonging to the genus Neorickettsia (order Rickettsiales, family Anaplasmataceae. Some Neorickettsia are able to invade cells of the digenean's vertebrate host and are known to cause diseases of wildlife and humans. In this study we report the results of screening 771 digenean samples for Neorickettsia collected from various vertebrates in terrestrial, freshwater, brackish, and marine habitats in the United States, China and Australia. Neorickettsia were detected using a newly designed real-time PCR protocol targeting a 152 bp fragment of the heat shock protein coding gene, GroEL, and verified with nested PCR and sequencing of a 1371 bp long region of 16S rRNA. Eight isolates of Neorickettsia have been obtained. Sequence comparison and phylogenetic analysis demonstrated that 7 of these isolates, provisionally named Neorickettsia sp. 1-7 (obtained from allocreadiid Crepidostomum affine, haploporids Saccocoelioides beauforti and Saccocoelioides lizae, faustulid Bacciger sprenti, deropegid Deropegus aspina, a lecithodendriid, and a pleurogenid represent new genotypes and one (obtained from Metagonimoides oregonensis was identical to a published sequence of Neorickettsia known as SF agent. All digenean species reported in this study represent new host records. Three of the 6 digenean families (Haploporidae, Pleurogenidae, and Faustulidae are also reported for the first time as hosts of Neorickettsia. We have detected Neorickettsia in digeneans from China and Australia for the first time based on PCR and sequencing evidence. Our findings suggest that further surveys from broader geographic regions and wider selection of digenean taxa are likely to reveal new Neorickettsia lineages as well as new digenean host associations.

  13. Consistent pattern of local adaptation during an experimental heat wave in a pipefish-trematode host-parasite system.

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    Susanne H Landis

    Full Text Available Extreme climate events such as heat waves are expected to increase in frequency under global change. As one indirect effect, they can alter magnitude and direction of species interactions, for example those between hosts and parasites. We simulated a summer heat wave to investigate how a changing environment affects the interaction between the broad-nosed pipefish (Syngnathus typhle as a host and its digenean trematode parasite (Cryptocotyle lingua. In a fully reciprocal laboratory infection experiment, pipefish from three different coastal locations were exposed to sympatric and allopatric trematode cercariae. In order to examine whether an extreme climatic event disrupts patterns of locally adapted host-parasite combinations we measured the parasite's transmission success as well as the host's adaptive and innate immune defence under control and heat wave conditions. Independent of temperature, sympatric cercariae were always more successful than allopatric ones, indicating that parasites are locally adapted to their hosts. Hosts suffered from heat stress as suggested by fewer cells of the adaptive immune system (lymphocytes compared to the same groups that were kept at 18°C. However, the proportion of the innate immune cells (monocytes was higher in the 18°C water. Contrary to our expectations, no interaction between host immune defence, parasite infectivity and temperature stress were found, nor did the pattern of local adaptation change due to increased water temperature. Thus, in this host-parasite interaction, the sympatric parasite keeps ahead of the coevolutionary dynamics across sites, even under increasing temperatures as expected under marine global warming.

  14. Characterization of the complete mitochondrial genome sequence of Homalogaster paloniae (Gastrodiscidae, Trematoda) and comparative analyses with selected digeneans.

    Science.gov (United States)

    Yang, Xin; Wang, Lixia; Feng, Hanli; Qi, Mingwei; Zhang, Zongze; Gao, Chong; Wang, Chunqun; Hu, Min; Fang, Rui; Li, Chengye

    2016-10-01

    Gastrodiscidae species are neglected but significant paramphistomes in small ruminants, which can lead to considerable economic losses to the breeding industry of livestock. However, knowledge about molecular ecology, population genetics, and phylogenetic analysis is still limited. In the present study, we firstly sequenced and analyzed the full mitochondrial (mt) genome of Homalogaster paloniae (14,490 bp). The gene contents and organization of the H. paloniae mt genome is the same as that of other digeneans, such as Fasciola hepatica and Paramphistomum cervi. It is interesting that unlike other paramphistomes, H. paloniae is flat in shape which is similar with Fasciola, such as F. hepatica. Phylogenetic analysis of H. paloniae and other 17 selected digeneans using concatenated amino acid sequences of the 12 protein-coding genes showed that Gastrodiscidae is closely related to Paramphistomidae and Gastrothylacidae. The availability of the mt genome sequence of H. paloniae should provide an important foundation for further molecular study of Gastrodiscidae and other digeneans.

  15. New records of digeneans from Podocnemis spp. (Testudines, Podocnemididae from Iquitos, Peru

    Directory of Open Access Journals (Sweden)

    Manuel Tantaleán

    2011-06-01

    Full Text Available We obtained 8 digestive tract of the turtle Podocnemis expansa and 18 of P. unifilis from the Belen market (Iquitos, Peru. Only digeneans were studied and identified. Four species were found: Nematophila grandis (Diesing, 1839 Travassos, 1934, Halltrema avitellina Lent & Freitas, 1939, Podocnemitrema papillosum Alho & Vicente, 1964 and Telorchis hagmanni Lent & Freitas, 1937. Halltrema avitellina, Podocnemitrema papillosum and Telorchis hagmanni are new records from Peru.

  16. The distribution of digenean metacercariae within bream (Abramis brama) gill apparatus: preferences, co-occurrence and interactions of parasites.

    Science.gov (United States)

    Zolovs, M; Kanto, J; Jakubāne, I

    2017-05-24

    Species-specific microenvironmental preferences and interactions between parasite species have been the focus of many ecological studies. Here, we studied the distribution of ectoparasite species within the gill apparatus of bream (Abramis brama) from Lake Lubāns (Latvia) to establish whether digenean metacercariae: (1) prefer specific patches within the gill apparatus; (2) co-occur in the same patches with monogeneans and copepods within a host individual; and (3) interact with monogeneans and copepods. We recorded all parasites on gill arches of the same host species and used null models to analyse co-occurrences of digenean metacercariae, monogeneans and copepods. Zero-inflated mixture models were used to define the preferred patches of parasites. We found that digenean metacercariae (Bucephalus polymorphus) prefer specific patches of the gill apparatus to encyst, and shared these preferences with monogeneans and copepods, but did not interact with them. We concluded that digenean metacercariae have a species-specific microenvironmental preference to encyst in the gill apparatus and their occurrence (even in high numbers) does not reduce the success of attachment of monogeneans and copepods in the same gill patches.

  17. 淮南地区禽畜体内寄生人兽共患吸虫的种类%Zoonotic trematode species identified in domestic animals from Huainan area

    Institute of Scientific and Technical Information of China (English)

    李朝品; 孙恩涛; 朱玉霞; 田晔; 沈静; 湛孝东; 赵金红

    2014-01-01

    Objective To understand the zoonotic trematode species identified in domestic animals from Huainan area,An-hui Province,so as to supply the evidence for the prevention of zoonoses. Methods The livestock/definitive hosts were commer-cially available on category basis,and sacrificed for obtaining the parasitic samples via dissecting the viscera. The specimens were microscopically identified,with reference to the descriptions in the previous literature. Results By identification,sorting and classification,41 species of internal trematodes were found so far in the domestic animals fed in Huainan areas,in which 23 spe-cies were zoonotic trematodes and 18 were internally parasitic in livestock,belonging to 4 orders,12 families and 21 genera,and occurred in 9 definitive hosts including chicken,ducks,geese,pigs,cattle,buffaloes,sheep,goats and dogs,respectively. Con-clusion The findings suggest that the zoonotic trematodes belong to many kinds and prevalent in the domestic animals in Huainan areas,and such prevalence should call for high attention since it is urgent risk factors for zoonoses in this geographic area.%目的:了解安徽省淮南地区禽畜体内寄生人兽共患吸虫的种类,为防治人兽共患吸虫病提供参考依据。方法从淮南市禽畜市场选购人兽共患吸虫的终宿主,处死后取出内脏并解剖,获取虫体,制片鉴定,同时检索整理有关淮南地区禽畜体内寄生吸虫的文献。结果经分类、鉴定和整理,淮南地区禽畜体内寄生吸虫迄今共发现41种,其中人兽共患吸虫23种,仅在禽畜体内寄生吸虫18种,分属4目12科21属,分别寄生于鸡、鸭、鹅、猪、黄牛、水牛、绵羊、山羊和犬等9种终宿主。结论淮南地区禽畜体内寄生人兽共患吸虫的种类较多,引起人群人兽共患吸虫病传播与流行的危险较高,应引起高度重视。

  18. Membrane Attack Complex/Perforin domain-containing proteins in a dual-species transcriptome of caenogastropoda Littorina littorea and its trematode parasite Himasthla elongata.

    Science.gov (United States)

    Gorbushin, Alexander M

    2016-07-01

    The MACPF domain-containing proteins potentially able to build a transmembrane pore structure are found in the transcriptome of a common periwinkle kidney loaded with trematode rediae. Two homologs of mammalian Macrophage expressed gene 1 (Mpeg1), LlMpeg1-1 and LIMpeg1-2, share similar domain structure with the only difference such as LIMpeg1-2 transcript lacks of a C-terminal transmembrane helix. Expression of membrane-anchored protein LlMpeg1-1 is similar in kidneys of naturally infected with trematode Himasthla elongata and uninfected snails. The expression of the second soluble LIMpeg1-2 protein is 4-fold upregulated under infection. The third MACPF protein found in Littorina littorea kidney is homologous with Perivitellin - 2 67 kDa subunit named LlPV2-67 and the expression of the transcript is 3-fold upregulated in the kidney of infected snails. The last two molecules are candidate effectors that may participate in the immune response of common periwinkles to trematode infestation. A single parasite-expressed MACPF-like protein was recorded from the transcriptome of Himasthla elongata.

  19. Cell types and structures involved in tench, Tinca tinca (L.), defence mechanisms against a systemic digenean infection.

    Science.gov (United States)

    Dezfuli, B S; Lui, A; Pironi, F; Manera, M; Shinn, A P; Lorenzoni, M

    2013-06-01

    Histopathological and ultrastructural investigations were conducted on 36 tench, Tinca tinca (L.), from Lake Trasimeno (Italy). The gills, intestine, liver, spleen, kidney and heart of 21 individuals were found to harbour an extensive infection of larvae of an unidentified digenean trematode. The eyes, gonads, swim bladder and muscles were uninfected. The parasites in each tissue type were embedded in a granulomatous proliferation of tissue, forming a reactive fibroconnective capsule around each larva. Most of the encysted larvae were metacercariae, in a degenerative state, but on occasion some cercariae were found. Many of the granulomas were either necrotic or had a calcified core. Within the granuloma of each, the occurrence of granulocytes, macrophages, rodlet cells and pigment-bearing macrophage aggregates was observed. Hearts bore the highest parasitic infection. Whilst the presence of metacercariae within the intestine was found positioned between the submucosa and muscle layers, metacercariae in the liver were commonly found encysted on its surface where the hepatocytes in close contact with the granuloma were observed to have electron-lucent vesicles within their cytoplasm. Metacercariae encysting adjacent to the cartilaginous rods of gill filaments were seen to elicit a proliferation of the cartilage from the perichondrium. Rodlet cells, neutrophils and mast cells were frequently observed in close proximity to, and within, infected gill capillaries. Given the degenerated state of most granulomas, a morphology-based identification of the enclosed digeneans was not possible.

  20. [Trematodes of birds (Aves) from the Middle Volga region. 1. Orders Brachylaimidae, Cyclocoelida, Echinostomatida, Notocotylida, and Opisthorchiida].

    Science.gov (United States)

    Kirillov, A A; Kitillova, N Iu

    2013-01-01

    The data on trematodes of the orders Brachylaimidae, Cyclocoelida, Echinostomatida, Notocotylida, and Opisthorchiida from the Middle Volga region are given. Records of different authors are supplemented with the results of our own research. Reliable records are confirmed for 61 trematode species. The following characteristics for each parasite species are given: the systematic position, the host spectrum, locality, collecting sites, biology, degree of host specificity, and the geographical range. Morphological descriptions and original figures of 3 trematodes species are given.

  1. Optimization of Conditions for In Vitro Culture of the Microphallid Digenean Gynaecotyla adunca.

    Science.gov (United States)

    West, Jenna; Mitchell, Alexandra; Pung, Oscar J

    2014-01-01

    In vitro cultivation of digeneans would aid the development of effective treatments and studies of the biology of the parasites. The goal of this study was to optimize culture conditions for the trematode, Gynaecotyla adunca. Metacercariae of the parasite from fiddler crabs, Uca pugnax, excysted in trypsin, were incubated overnight to permit fertilization, and were cultured in different conditions to find those that resulted in maximum worm longevity and egg production. When cultured in media lacking serum, worms lived longer in Hanks balanced salt solution and Dulbecco's Modified Eagle medium/F-12 (DME/F-12) than in RPMI-1640 but produced the most eggs in DME/F-12. Worm longevity and egg production increased when worms were grown in DME/F-12 supplemented with 20% chicken, horse, or newborn calf serum but the greatest number of eggs was deposited in cultures containing horse or chicken serum. Horse serum was chosen over chicken serum due to the formation of a precipitate in chicken serum. The optimal concentration of horse serum with respect to egg production ranged from 5 to 20%. Infectivity of eggs deposited by worms in culture was tested by feeding eggs to mud snails, Ilyanassa obsoleta. None of these snails produced G. adunca cercariae.

  2. Optimization of Conditions for In Vitro Culture of the Microphallid Digenean Gynaecotyla adunca

    Directory of Open Access Journals (Sweden)

    Jenna West

    2014-01-01

    Full Text Available In vitro cultivation of digeneans would aid the development of effective treatments and studies of the biology of the parasites. The goal of this study was to optimize culture conditions for the trematode, Gynaecotyla adunca. Metacercariae of the parasite from fiddler crabs, Uca pugnax, excysted in trypsin, were incubated overnight to permit fertilization, and were cultured in different conditions to find those that resulted in maximum worm longevity and egg production. When cultured in media lacking serum, worms lived longer in Hanks balanced salt solution and Dulbecco’s Modified Eagle medium/F-12 (DME/F-12 than in RPMI-1640 but produced the most eggs in DME/F-12. Worm longevity and egg production increased when worms were grown in DME/F-12 supplemented with 20% chicken, horse, or newborn calf serum but the greatest number of eggs was deposited in cultures containing horse or chicken serum. Horse serum was chosen over chicken serum due to the formation of a precipitate in chicken serum. The optimal concentration of horse serum with respect to egg production ranged from 5 to 20%. Infectivity of eggs deposited by worms in culture was tested by feeding eggs to mud snails, Ilyanassa obsoleta. None of these snails produced G. adunca cercariae.

  3. Collection methods of trematode eggs using experimental animal models.

    Science.gov (United States)

    Tsubokawa, Daigo; Sugiyama, Hiromu; Mikami, Fusako; Shibata, Katsumasa; Shibahara, Toshiyuki; Fukuda, Koichi; Takamiya, Shinzaburo; Yamasaki, Hiroshi; Nakamura, Takeshi; Tsuji, Naotoshi

    2016-10-01

    Although observing the eggs of human parasitic helminth is essential for medical education in parasitology, opportunities for collection of the eggs are limited. Collection of the eggs using experimental animal models is needed for a sustainable supply. The metacercariae of three trematode species, Paragonimus westermani, Clonorchis sinensis and Metagonimus yokogawai, were collected from the second intermediate hosts: freshwater crabs and fishes, which were obtained using online shopping in Japan, and inoculated to experimental animal rat and dog. Consequently, eggs of the three trematode species were obtained abundantly from the feces of the animals. The eggs are being used for student training in several Japanese universities. In this article, we introduce the collection procedures for trematode eggs.

  4. Range size patterns in European freshwater trematodes

    DEFF Research Database (Denmark)

    Thieltges, David; Hof, Christian; Borregaard, Michael Krabbe

    2011-01-01

    Aim We investigated the relationship between host and parasite diversity as well as latitudinal gradients in parasite diversity on a continental scale in European freshwater trematodes. Location European freshwaters. Methods We extracted distributional data for 564 freshwater trematodes across 25...

  5. Larval trematode infections in Lymnaea glabra populations living in the Brenne Regional Natural Park, central France.

    Science.gov (United States)

    Rondelaud, Daniel; Vignoles, Philippe; Dreyfuss, Gilles

    2015-01-01

    Lymnaea glabra is known to be a natural intermediate host of two flukes, Calicophoron daubneyi and Fasciola hepatica, in central France. But it can also sustain larval development of other digeneans. Adult snails were thus collected from 206 habitats in 2014 and 2015 to identify parasite species and determine the prevalence of each digenean infection in relation to the five types of snail habitats. Seven digenean species were noted in 321 infected snails (out of 17,647 L. glabra). Snails with F. hepatica or C. daubneyi were found in 14.5% and 12.6% of habitats, respectively. Percentages were lower for snails with Opisthoglyphe ranae (5.8%), Haplometra cylindracea (5.3%) and were less than 5% for those infected with Echinostoma revolutum, Notocotylus sp. or Plagiorchis sp. Prevalence noted for each parasite species varied with the type of habitat. The number of species in L. glabra was lower than that found in G. truncatula from the same region (7 instead of 10). The distribution and prevalence of each digenean species were thus dependent on the type and location of each snail habitat. © D. Rondelaud et al., published by EDP Sciences, 2015.

  6. Larval trematode infections in Lymnaea glabra populations living in the Brenne Regional Natural Park, central France

    Directory of Open Access Journals (Sweden)

    Rondelaud Daniel

    2015-01-01

    Full Text Available Lymnaea glabra is known to be a natural intermediate host of two flukes, Calicophoron daubneyi and Fasciola hepatica, in central France. But it can also sustain larval development of other digeneans. Adult snails were thus collected from 206 habitats in 2014 and 2015 to identify parasite species and determine the prevalence of each digenean infection in relation to the five types of snail habitats. Seven digenean species were noted in 321 infected snails (out of 17,647 L. glabra. Snails with F. hepatica or C. daubneyi were found in 14.5% and 12.6% of habitats, respectively. Percentages were lower for snails with Opisthoglyphe ranae (5.8%, Haplometra cylindracea (5.3% and were less than 5% for those infected with Echinostoma revolutum, Notocotylus sp. or Plagiorchis sp. Prevalence noted for each parasite species varied with the type of habitat. The number of species in L. glabra was lower than that found in G. truncatula from the same region (7 instead of 10. The distribution and prevalence of each digenean species were thus dependent on the type and location of each snail habitat.

  7. Biodiversity of trematodes associated with amphibians from a variety of habitats in Corrientes Province, Argentina.

    Science.gov (United States)

    Hamann, M I; Kehr, A I; González, C E

    2013-09-01

    The main goals of this study were to compare the richness of parasitic trematodes in amphibians with diverse habits (terrestrial, fossorial, semi-aquatic and arboreal), and to evaluate whether the composition of the trematode community is determined by ecological relationships. Specimens were collected between April 2001 and December 2006 from a common area (30 ha) in Corrientes Province, Argentina. Trematodes of amphibians in this area comprised a total of 19 species, and were dominated by common species. Larval trematodes presented highest species richness, with the metacercaria of Bursotrema tetracotyloides being dominant in the majority (7/9, 78%) of the parasite communities. Adults of the trematode Catadiscus inopinatus were dominant in the majority (6/9, 67%) of amphibians. The amphibians Leptodactylus latinasus, Leptodactylus bufonius and Scinax nasicus presented a high diversity of trematodes, whereas Leptodactylus chaquensis had the lowest diversity even though it presented with the highest species richness. The patterns of similarity among amphibian species showed groups linking with their habitats. Leptodactilid amphibians, with a generalist diet and an active foraging strategy showed highest infection rates with adult trematodes. The mean richness of trematode species related to host's habitat preferences was higher in semi-aquatic amphibians. Results suggest that semi-aquatic amphibians, present in both aquatic and terrestrial environments, present a greater diversity of parasites as they have a higher rate of exposure to a wider range of prey species and, hence, to diverse infective states. The trematode composition is related to the diets and mobility of the host, and habitat.

  8. Potential Zoonotic Trematodes Recovered in Stray Cats from Kuwait Municipality, Kuwait.

    Science.gov (United States)

    El-Azazy, Osama Mohamed ElShfei; Abdou, Nadra-Elwgoud Mohamed Ibrahim; Khalil, Amal Iskander; Al-Batel, Maha Khaled; Majeed, Qais Abdulrazak Habeeb; Henedi, Adawia Abdul-Ruhman; Tahrani, Laila Mohamed Azad

    2015-06-01

    Stray cats are a common feature roaming the streets and alleys of Kuwait; they could be a source of parasites, including trematodes, that affect humans. A survey was conducted to identify feline trematodes and throw the light on their public health significance in Kuwait. Out of 240 stray cats trapped from different localities of Kuwait from June 2011 to May 2012, 59 (24.6%) were found to be infected with 14 species of trematodes. The most common were trematodes of the genus Heterophyes, particularly H. heterophyes and H. dispar that were found in respectively 15.8% and 10.8% of the cats examined. Other trematodes recorded, with lower prevalences, were Heterophyes nocens (2.9%), Haplorchis taichui (3.8%), Stictodora sawakinensis (2.1%), Stellantchasmus falcatus (1.6%), Echinochasmus japonicus (1.6%), and Mesostephanus dottrensi (1.3%). Centrocestus cuspidatus, Galactosomum fregatae, Ascocotyle sp., Mesostephanus appendiculatus, Haplorchis yokogawai, and Pygidiopsis genata showed the lowest prevalence (0.4%) and intensity. The majority of the trematodes are recorded for the first time in Kuwait and even in the Gulf region. The study reveals that stray cats are good indicators of fish-borne trematodes in the environment. As all trematodes recovered are zoonotic, their significance to public health should be considred.

  9. 广东省6种蝙蝠寄生2种斜睾科吸虫的记述%Study on two species of Trematodes in Plagiorchiidae in six bats species from Guangdong Province

    Institute of Scientific and Technical Information of China (English)

    李海燕; 吴毅

    2011-01-01

    One hundred and twenty-nine specimens in six ba'ts species,which belong to four genera three families,were captured from 2008 to 2010. Two species of trematodes, Plagiorchis t,espertilionis ( Muller, 1780) Braun,1900 and P. koreanus Ogata, 1900,belonging to the Family Plagiorehiidaethe ,the genus Plagiorchis were obtained from the intestine of bats collected at three localities of ()uangdong Province. The prmalence of P. re.spertilionis 10% (4/40) , of P. koreanu.s 8.05%(7/87). The infeelion intensit) oi P. vespertilionis u:ere 3 - 10 individuals,of P. koreanus were 1 -8 individuals. Scotophilus kuhlii and S. heathii are first recorded hosts of P. vespertilionis, Hipposideros armiger,Scotophilu.kuhlii. S. heathii, Rhinolophu .sper.sonii and R. pusillus are first recorded hosts of P. koreanus.%2008~2010年对广东省3个产地的3科4属6种129只蝙蝠的与化道寄生虫进行调查,发现斜睾科Plagiorchiidae斜睾属Plagiorchis吸虫2种:坞蝠钭睾吸虫Plagiorhis tespertilionis(Muller,1780)Braun,1900和朝鲜钭睾吸虫P.koreanus Ogata,1900蝙蝠斜睾叹虫色宿主中的感染卓为10%(4/40),感染强度1~10条;朝鲜斜睾吸虫在宿主中的感染率为8.05%(7/87),感染强度为1~8条小黄蝠Scoto#hilus kuhlii和大黄蝠S.heathi为蝙蝠钭睾吸虫的宿主新记录;大蹄蝠Hipposidderos arnliger.小黄蝠sctophilus kuhlii,大黄蝠S.heathii,皮氏菊头蝠Rhinolophus personi和小菊头蝠R.pusillu为朝鲜斜睾吸虫的宿主新记录.

  10. Real-time PCR detection and phylogenetic relationships of Neorickettsia spp. in digeneans from Egypt, Philippines, Thailand, Vietnam and the United States.

    Science.gov (United States)

    Greiman, Stephen E; Vaughan, Jefferson A; Elmahy, Rasha; Adisakwattana, Poom; Van Ha, Nguyen; Fayton, Thomas J; Khalil, Amal I; Tkach, Vasyl V

    2017-02-01

    Neorickettsia (Rickettsiales, Anaplasmataceae) is a genus of obligate intracellular bacterial endosymbionts of digeneans (Platyhelminthes, Digenea). Some Neorickettsia are able to invade cells of the digenean's vertebrate host and are known to cause diseases of domestic animals, wildlife, and humans. In this study we report the results of screening digenean samples for Neorickettsia collected from bats in Egypt and Mindoro Island, Philippines, snails and fishes from Thailand, and fishes from Vietnam and the USA. Neorickettsia were detected using a real-time PCR protocol targeting a 152bp fragment of the heat shock protein coding gene, GroEL, and verified with nested PCR and sequencing of a 1853bp long region of the GroESL operon and a 1371bp long region of 16S rRNA. Eight unique genotypes of Neorickettsia were obtained from digenean samples. Neorickettsia sp. 8 obtained from Lecithodendrium sp. from Egypt; Neorickettsia sp. 9 and 10 obtained from two species of Paralecithodendrium from Mindoro, Philippines; Neorickettsia sp. 11 from Lecithodendrium sp. and Neorickettsia sp. 4 (previously identified from Saccocoelioides lizae, from China) from Thailand; Neorickettsia sp. 12 from Dicrogaster sp. Florida, USA; Neorickettsia sp. 13 and SF agent from Vietnam. Sequence comparison and phylogenetic analysis demonstrated that the forms, provisionally named Neorickettsia sp. 8-13, represent new genotypes. We have for the first time detected Neorickettsia in a digenean from Egypt (and the African continent as a whole), the Philippines, Thailand and Vietnam based on PCR and sequencing evidence. Our findings suggest that further surveys from the African continent, SE Asia, and island countries are likely to reveal new Neorickettsia lineages as well as new digenean host associations.

  11. The role of spatial and temporal heterogeneity and competition in structuring trematode communities in the great pond snail, Lymnaea stagnalis (L.)

    Science.gov (United States)

    Soldánová, Miroslava; Kuris, Armand M.; Scholz, Tomáš; Lafferty, Kevin D.

    2012-01-01

    We assessed how spatial and temporal heterogeneity and competition structure larval trematode communities in the pulmonate snail Lymnaea stagnalis. To postulate a dominance hierarchy, mark-release-recapture was used to monitor replacements of trematode species within snails over time. In addition, we sampled the trematode community in snails in different ponds in 3 consecutive years. A total of 7,623 snails (10,382 capture events) was sampled in 7 fishponds in the Jindřichův Hradec and Třeboň areas in South Bohemia (Czech Republic) from August 2006 to October 2008. Overall, 39% of snails were infected by a community of 14 trematode species; 7% of snails were infected with more than 1 trematode species (constituting 16 double- and 4 triple-species combinations). Results of the null-model analyses suggested that spatial heterogeneity in recruitment among ponds isolated trematode species from each other, whereas seasonal pulses in recruitment increased species interactions in some ponds. Competitive exclusion among trematodes led to a rarity of multiple infections compared to null-model expectations. Competitive relationships among trematode species were hypothesized as a dominance hierarchy based on direct evidence of replacement and invasion and on indirect evidence. Seven top dominant species with putatively similar competitive abilities (6 rediae and 1 sporocyst species) reduced the prevalence of the other trematode species developing in sporocysts only.

  12. [Trematodes of birds (Aves) from the Middle Volga region. 2. Orders Plagiorchiida, Renicolida, Strigeida, and Schistosomatida].

    Science.gov (United States)

    Kirillov, A A; Kirillova, N Iu

    2013-01-01

    Data on trematodes of Plagiorchiida, Renicolida, Strigeida, and Schistosomatida, parasitizing in birds of the Middle Volga region are given. Proceedings of the different authors are supplemented by results of our research. Two species of trematodes (Brachylaima mesostoma and Mosesia amplavaginata) are specified for birds of the middle Volga region for the first time. New hosts were revealed for 2 trematode species: the great tit for Plagiorchis laricola and the common chaffinch for M. amplavaginata. The following characteristics for each parasite are given: it's systematic position, the spectrum of hosts, localization, collecting site, biology, the degree of host specificity and geographical range. The morphological description and original figures of 11 species of trematodes are presented.

  13. IMPORTANT TREMATODES IN MAN IN INDONESIA

    Directory of Open Access Journals (Sweden)

    Pinardi Hadidjaja

    2012-09-01

    Full Text Available Trematode infections are considered to be a non public health problem in Indonesia, with the excep­tion of the two species namely Schistosoma japonicum and Fasciolopsis buski which are still assumed to be the most important trematodes of Indonesia. Other trematode infections reported occasionally were caused by: Echinostoma spp, Haplorchis yokogawai, Haplorchis taichui, Paralecithodendrium molenkampi, Phaneropsolus bonnei and Plachiorchis javensis. Schistosoma japonicum infection has been known to be endemic among the inhabitants of Lake Lindu since 1937. Surveys carried out since that time revealed prevalence rates which varied from 8-55%. Further studies proved that the species at Lindu were similar to the species found in Asia. Resurvey initiated in 1971 gave almost a similar prevalence rate followed by the discovery of the molluscan intermediate host namely Oncomelania hupensis lindoensis. In 1972 a new focus of schistosomiasis was discovered at Napu Valley. Other survey did not reveal any other endemic foci. The result of a biological study carried out since 1976 reconfirmed the diagnosis of the species. Clinical study showed that the significant signs and symptoms of schistosomiasis found among the Lindu inhabitants were : dermatitis, diarrhea, dysentry, abdominal pain, nausea and vomiting, loss of appetite, weakness, distention of the abdomen, melaena. hepatomegaly and splenomegaly. Control of schistosomiasis was initiated in 1981, using praziquantel for mass treatment. Twelve cycles of treatment at Lake Lindu area and 10 cycles at Napu Valley resulted in a reduction of overall prevalence rate from 15,80 % at Lindu area in 1981 to 1,14 % in 1987 whereas in Napu Valley the reduction was from 35,8 % in 1982 to 1,00 % in 1987. Fasciolopsis buski infection was first reported in 1982 from the Regency of Babirik, Hulu Sungai Utara in South Kalimantan Province. The following survey in that area in 1986 revealed a prevalence rate of 27

  14. Caste ratios affect the reproductive output of social trematode colonies.

    Science.gov (United States)

    Kamiya, T; Poulin, R

    2013-03-01

    Intraspecific phenotypic diversification in social organisms often leads to formation of physical castes which are morphologically specialized for particular tasks within the colony. The optimal caste allocation theory argues that specialized morphological castes are efficient at specific tasks, and hence different caste ratios should affect the ergonomic efficiency, hence reproductive output of the colony. However, the reproductive output of different caste ratios has been documented in few species of insects with equivocal support for the theory. This study investigated whether the ratios of nonreproductive and reproductive morphs affect the reproductive output of a recently discovered social trematode, Philophthalmus sp., in which the nonreproductive members are hypothesized to be defensive specialists. A census of natural infections and a manipulative in vitro experiment demonstrated a positive association between the reproductive output of trematode colonies and the ratio of nonreproductive to reproductive morphs in the presence of an intra-host trematode competitor, Maritrema novaezealandensis. On the contrary, without the competitor, reproductive output was negatively associated with the proportion of nonreproductive castes in colonies. Our findings demonstrate for the first time a clear fitness benefit associated with the nonreproductive castes in the presence of a competitor while illustrating the cost of maintaining such morphs in noncompetitive situations. Although the proximate mechanisms controlling caste ratio remain unclear in this trematode system, this study supports the prediction that the fitness of colonies is influenced by the composition of specialized functional morphs in social organisms, suggesting a potential for adaptive shifts of caste ratios over evolutionary time.

  15. Digenetic trematodes in South American sea lions from southern Brazilian waters.

    Science.gov (United States)

    Pereira, E M; Müller, G; Secchi, E; Pereira, J; Valente, A L S

    2013-10-01

    The aim of this work was to perform a systematic study to detect and quantify the digenetic trematode infections in South American sea lions from the southern Brazilian coast. Twenty-four South American sea lions, Otaria flavescens (Carnivora: Otaridae), were found dead along the coast of Rio Grande do Sul State, Brazil, between June 2010 and September of 2011. Two trematode species were found in the intestines of O. flavescens, i.e., Stephanoprora uruguayense (Digenea: Echinostomatidae) and Ascocotyle (Phagicola) longa (Digenea: Heterophyidae). Ascocotyle (P.) longa reached a prevalence of 33.3% and mean intensity of 248,500, whereas S. uruguayense showed a prevalence of 4.2% and mean intensity of 202. The 2 trematode species infecting sea lions were likely transmitted by feeding on mullets, Mugil platanus, that commonly harbor heterophyid metacercariae. The present work is the first report of digenetic trematodes infecting O. flavescens in Brazil. The high prevalence and mean intensity values of the 2 trematode species infecting sea lions in the present study suggest caution in human consumption of mullets and other fish, which can be infected with the metacercariae of these trematodes known to have zoonotic potential.

  16. A species pair of Bivesicula Yamaguti, 1934 (Trematoda: Bivesiculidae) in unrelated Great Barrier Reef fishes: implications for the basis of speciation in coral reef fish trematodes.

    Science.gov (United States)

    Trieu, Nancy; Cutmore, Scott C; Miller, Terrence L; Cribb, Thomas H

    2015-07-01

    Combined morphological and molecular analysis shows that a species of Bivesicula Yamaguti, 1934 from four species of Apogonidae Günther [Nectamia fusca (Quoy & Gaimard), Ostorhinchus angustatus (Smith & Radcliffe), O. cookii (Macleay) and Taeniamia fucata (Cantor)] on the Great Barrier Reef is morphologically similar to, but clearly distinct from B. unexpecta Cribb, Bray & Barker, 1994 which infects a sympatric pomacentrid, Acanthochromis polyacanthus (Bleeker). Bivesicula neglecta n. sp. is proposed for the form from apogonids. Novel ITS2 rDNA sequences generated for the two species differ at just one consistent base position, implying that the two species are closely related. The combination of their close relationship, high but distinct specificity and co-occurrence suggests that speciation was driven by a recent host switching event enabled by similar dietary ecomorphology.

  17. On cestode and digenean parasites of Clarias gariepinus (Burchell, 1822 from the Rietvlei Dam, South Africa

    Directory of Open Access Journals (Sweden)

    M. Barson

    2006-09-01

    Full Text Available Sharptooth catfish, Clarias gariepinus, from the Rietvlei Dam near Pretoria, South Africa were examined for internal platyhelminth parasites. Two adult cestodes, Polyonchobothrium clarias (stomach (prev alence 71 %, mean intensity = 5, n = 7 and Proteocephalus glanduliger (anterior intestine (prevalence 14 %, mean intensity = 2, n = 7, were found in the gut while metacercariae of one larval digenean, Ornithodiplostomum sp. (prevalence 14 %, mean intensity = 140, n = 7, were found encysted in the muscles. The morphology of these species, based on light and scanning electron microscopy as well as histological analysis, and how they differ from previously described specimens, are discussed. Ornithodiplostomum is a new record in southern Africa. Infection levels of the host fish were mild compared to records from previous surveys.

  18. Digenean parasites of Atlantic horse mackerel (Trachurus trachurus in the Turkish Black Sea coast

    Directory of Open Access Journals (Sweden)

    Türkay Öztürk

    2016-03-01

    Full Text Available In the present study, we investigated the digenean parasites of Atlantic horse mackerel, Trachurus trachurus (L., 1758, in the Turkish Black Sea coast for the first time. Fish were collected throughout a year period from local fishermen in Sinop. A total of 256 fish specimens were weighed and measured, subsequently examined for parasites using conventional methods under an Olympus microscope (BX53 equipped with a digital camera (DP50. The examination included gills, pharynx, body cavity and visceral organs (stomach, intestine, liver, swim bladder and gonads. Parasites recovered were fixed and preserved using methods commonly applied. A total of five species including adults of Prodistomum polonii (Molin 1879 Bray and Gibson 1990, Ectenurus lepidus Looss, 1907, Monascus filiformis (Rudolphi, 1819 Looss, 1907, Lasiotocus typicus (Nicoll, 1912 and metacercaria of Stephanostomum cesticillum (Molin, 1858 Looss, 1899 were identified. Each parasite species were counted, their prevalence (% and mean intensity values were determined according to Bush et al. (1997. Kruskal-Wallis test (Non-parametric ANOVA was performed to find out the significant differences in the mean intensity values of the parasite for two length classes of fish as well as for the seasons. All the statistical tests were performed at the significance level of 5%. The calculated overall infection prevalence (% and mean intensity values were 48.8% and 3.78±0.34, respectively. This data is the first on the digenean parasite fauna of the Atlantic horse mackerel collected from the Turkish Black Sea coast. Lasiotocus typicus and Stephanostomum cesticillum are new parasite records for Turkey.

  19. Spermatozoon ultrastructure in two monorchiid digeneans

    Directory of Open Access Journals (Sweden)

    Yann Quilichini

    2016-09-01

    Full Text Available Spermatological characteristics of species from two monorchiid genera, Opisthomonorchis and Paramonorcheides, have been investigated, for the first time, by means of transmission electron microscopy. The ultrastructural study reveals that the mature spermatozoon of Opisthomonorchis dinema and Paramonorcheides selaris share several characters such as the presence of two axonemes of different lengths showing the 9+“1” pattern of the Trepaxonemata, a nucleus, two mitochondria, two bundles of parallel cortical microtubules, external ornamentation of the plasma membrane, spine-like bodies, granules of glycogen and similar morphologies of the anterior and posterior extremities. The slight differences between the male gamete of O. dinema and P. selaris are the length of the first axoneme and the position of the second mitochondrion. This study also elucidates the general morphology of the spermatozoon in all monorchiid species described so far, which corresponds to a unique spermatozoon type. Other interesting finds concern the spermatological similarities between monorchiid spermatozoa and the mature spermatozoon reported in the apocreadiid Neoapocreadium chabaudi. These similarities allow us to suggest a close phylogenetical relationship between the Monorchiidae and the Apocreadiidae, although more studies are needed, especially in the unexplored taxa.

  20. Trematode diversity in freshwater fishes of the Globe II: 'New World'.

    Science.gov (United States)

    Choudhury, Anindo; Aguirre-Macedo, M Leopoldina; Curran, Stephen S; de Núñez, Margarita Ostrowski; Overstreet, Robin M; de León, Gerardo Pérez-Ponce; Santos, Cláudia Portes

    2016-03-01

    We provide a summary overview of the diversity of trematode parasites in freshwater fishes of the 'New World', i.e. the Americas, with emphasis on adult forms. The trematode fauna of three regions, South America, Middle America, and USA and Canada (North America north of Mexico), are considered separately. In total, 462 trematode species have been reported as adults from the Americas. The proportion of host species examined for parasites varies widely across the Americas, from a high of 45% in the Mexican region of Middle America to less than 5% in South America. North and South America share no adult species, and one exclusively freshwater genus, Creptotrema Travassos, Artigas & Pereira, 1928 in the Allocreadiidae Looss, 1902 is the most widely distributed. Metacercariae of strigeiforms maturing in fish-eating birds (e.g. species of the Diplostomidae Poirier, 1886) are common and widely distributed. The review also highlights the paucity of known life-cycles. The foreseeable future of diversity studies belongs to integrative approaches and the application of molecular ecological methods. While opportunistic sampling will remain important in describing and cataloguing the trematode fauna, a better understanding of trematode diversity and biology will also depend on strategic sampling throughout the Americas.

  1. Trematode communities in snails can indicate impact and recovery from hurricanes in a tropical coastal lagoon.

    Science.gov (United States)

    Aguirre-Macedo, María Leopoldina; Vidal-Martínez, Victor M; Lafferty, Kevin D

    2011-11-01

    In September 2002, Hurricane Isidore devastated the Yucatán Peninsula, Mexico. To understand its effects on the parasites of aquatic organisms, we analyzed long-term monthly population data of the horn snail Cerithidea pliculosa and its trematode communities in Celestún, Yucatán, Mexico before and after the hurricane (February 2001 to December 2009). Five trematode species occurred in the snail population: Mesostephanus appendiculatoides, Euhaplorchis californiensis, two species of the genus Renicola and one Heterophyidae gen. sp. Because these parasites use snails as first intermediate hosts, fishes as second intermediate hosts and birds as final hosts, their presence in snails depends on food webs. No snails were present at the sampled sites for 6 months after the hurricane. After snails recolonised the site, no trematodes were found in snails until 14 months after the hurricane. It took several years for snail and trematode populations to recover. Our results suggest that the increase in the occurrence of hurricanes predicted due to climate change can impact upon parasites with complex life cycles. However, both the snail populations and their parasite communities eventually reached numbers of individuals and species similar to those before the hurricane. Thus, the trematode parasites of snails can be useful indicators of coastal lagoon ecosystem degradation and recovery.

  2. Trematode communities in snails can indicate impact and recovery from hurricanes in a tropical coastal lagoon

    Science.gov (United States)

    Aguirre-Macedo, Maria Leopoldina; Vidal-Martinez, Victor M.; Lafferty, Kevin D.

    2011-01-01

    In September 2002, Hurricane Isidore devastated the Yucatán Peninsula, Mexico. To understand its effects on the parasites of aquatic organisms, we analyzed long-term monthly population data of the horn snail Cerithidea pliculosa and its trematode communities in Celestún, Yucatán, Mexico before and after the hurricane (February 2001 to December 2009). Five trematode species occurred in the snail population: Mesostephanus appendiculatoides, Euhaplorchis californiensis, two species of the genus Renicola and one Heterophyidae gen. sp. Because these parasites use snails as first intermediate hosts, fishes as second intermediate hosts and birds as final hosts, their presence in snails depends on food webs. No snails were present at the sampled sites for 6 months after the hurricane. After snails recolonised the site, no trematodes were found in snails until 14 months after the hurricane. It took several years for snail and trematode populations to recover. Our results suggest that the increase in the occurrence of hurricanes predicted due to climate change can impact upon parasites with complex life cycles. However, both the snail populations and their parasite communities eventually reached numbers of individuals and species similar to those before the hurricane. Thus, the trematode parasites of snails can be useful indicators of coastal lagoon ecosystem degradation and recovery.

  3. Production of marine trematode cercariae: a potentially overlooked path of energy flow in benthic systems

    DEFF Research Database (Denmark)

    Thieltges, David W.; de Montaudouin, Xavier; Fredensborg, Brian

    2008-01-01

    reported for free-living invertebrates inhabiting benthic ecosystems. These estimates would be much higher if they included all trematode species in an ecosystem, and not just single-species values. Overall, results suggest that trematode cercariae represent potentially important paths of energy flow....... We use published data on rates at which trematodes produce free-swimming infective larvae (cercariae) that are released from their gastropod intermediate hosts to investigate patterns in cercarial output as a function of different variables, and to calculate the annual production of cercariae...... of cercariae, and was influenced by the type of downstream host sought by cercariae, being highest when this host was a vertebrate. Our estimates of annual cercarial production (kJ m-2 yr-1), which take into account the density of infected snails in the habitat, were within the range of production values...

  4. Small worms, big appetites: ratios of different functional morphs in relation to interspecific competition in trematode parasites.

    Science.gov (United States)

    Leung, Tommy L F; Poulin, Robert

    2011-08-15

    Animals living in colonies or collectives composed of highly-related individuals often produce morphs that are physically and behaviourally specialised to perform specific tasks. Because such morphs are often sterile, their production represents a fitness cost for the colony and there should be an optimal ratio of the numbers of sterile specialists and reproductive members that may be adjustable to environmental conditions. Trematode parasites undergo asexual multiplication within their snail intermediate host, resulting in large numbers of clonal stages known as rediae or sporocysts, depending on the trematode species. In areas with high prevalences of infection, the host can be infected by multiple species, which can lead to intense competition for limited resources. Here, we describe the existence of specialised 'mini-rediae' in the trematode Philophthalmus sp. that are morphologically and functionally specialised for interspecific competition. Mini-rediae were observed feeding on the sporocysts of a co-occurring trematode species -Maritrema novaezealandensis. In addition, in larger snails - which are less likely to have M. novaezealandensis infections -Philophthalmus sp. produces relatively fewer mini-rediae than expected. Our findings support results from a prior study which demonstrated the existence of morphs that perform specialised functions in antagonistic interspecific interactions in trematodes, and additionally shows that the number of these morphs in each host is associated with the likelihood of encountering other species within the same host. Trematodes may thus provide interesting models for studying morphological specialisation in colonial organisms.

  5. Diversity increases biomass production for trematode parasites in snails

    Science.gov (United States)

    Hechinger, Ryan F.; Lafferty, Kevin D.; Kuris, Armand M.

    2008-01-01

    Increasing species diversity typically increases biomass in experimental assemblages. But there is uncertainty concerning the mechanisms of diversity effects and whether experimental findings are relevant to ecological process in nature. Hosts for parasites provide natural, discrete replicates of parasite assemblages. We considered how diversity affects standing-stock biomass for a highly interactive parasite guild: trematode parasitic castrators in snails. In 185 naturally occurring habitat replicates (individual hosts), diverse parasite assemblages had greater biomass than single-species assemblages, including those of their most productive species. Additionally, positive diversity effects strengthened as species segregated along a secondary niche axis (space). The most subordinate species—also the most productive when alone—altered the general positive effect, and was associated with negative diversity effects on biomass. These findings, on a previously unstudied consumer class, extend previous research to illustrate that functional diversity and species identity may generally both explain how diversity influences biomass production in natural assemblages of competing species.

  6. The role of competition – colonization tradeoffs and spatial heterogeneity in promoting trematode coexistence

    Science.gov (United States)

    Mordecai, Erin A.; Jaramillo, Alejandra G.; Ashford, Jacob E.; Hechinger, Ryan F.; Lafferty, Kevin D.

    2016-01-01

    Competition – colonization tradeoffs occur in many systems, and theory predicts that they can strongly promote species coexistence. However, there is little empirical evidence that observed competition – colonization tradeoffs are strong enough to maintain diversity in natural systems. This is due in part to a mismatch between theoretical assumptions and biological reality in some systems. We tested whether a competition – colonization tradeoff explains how a diverse trematode guild coexists in California horn snail populations, a system that meets the requisite criteria for the tradeoff to promote coexistence. A field experiment showed that subordinate trematode species tended to have higher colonization rates than dominant species. This tradeoff promoted coexistence in parameterized models but did not fully explain trematode diversity and abundance, suggesting a role of additional diversity maintenance mechanisms. Spatial heterogeneity is an alternative way to promote coexistence if it isolates competing species. We used scale transition theory to expand the competition – colonization tradeoff model to include spatial variation. The parameterized model showed that spatial variation in trematode prevalence did not isolate most species sufficiently to explain the overall high diversity, but could benefit some rare species. Together, the results suggest that several mechanisms combine to maintain diversity, even when a competition – colonization tradeoff occurs.

  7. [Molecular genetic characterization of the Far Eastern trematode Skrjabino lecithum spasskii Belous, 1954 (Digenea: Haploporidae)), a parasite of mullets].

    Science.gov (United States)

    Atopkin, D M; Nikitenko, A Yu; Ngo, H D; Ha, N V; Tang, N V

    2015-01-01

    Intraspecific genetic differentiation of the trematode Skrjabinolecithum spasskii and its phylogenetic relationships with other species of the family Haploporidae were studied by comparing the nucleotide sequences of a part of the 28S rRNA gene and the ITS1-5.8S-ITS2 rDNA region. Trematodes were isolated from so-iuy mullet Liza haematocheila fishes collected in rivers of Primorye and flathead grey mullet Mugil cephalus fishes collected in water bodies of Vietnam (27 fishes in total). A phylogenetic analysis showed that S. spasskii is close to species of the genus Capitimitta of the subfamily Waretrematinae. By intraspecific variation of rDNA sequences, trematodes were divided into three groups with tree different genotypes, which had fixed nucleotide substitutions. Genotype I was found in trematodes from fishes collected in Primorye. Genotype II was detected in trematodes from M. cephalus fishes collected in the Tonkin Bay, Cat Ba Island, Vietnam. Genotype III was found in five trematodes from L. haematocheila collected in the Kievka River, Primorye. The genetic distances between genotypes I and III from Primorye were 0.4 and 0.65% by 28S and ITS rDNA sequences, respectively. The lowest genetic distances were observed between genotypes II (Vietnam) and III (Primorye), 0.1 and 0.33% by 28S and ITS rDNA sequences, respectively. Possible causes of genetic differentiation of S. spasskii from different geographic locations and different definitive host species are discussed.

  8. Ultrastructure of the spermatozoon of the digenean Plagiorchis elegans (Rudolphi, 1802) (Plagiorchioidea, Plagiorchiidae).

    Science.gov (United States)

    Ndiaye, Papa Ibnou; Quilichini, Yann; Tkach, Vasyl V; Greiman, Stephen E; Bâ, Cheikh Tidiane; Marchand, Bernard

    2013-09-01

    The ultrastructure of the mature spermatozoon of the type genus of the Plagiorchiidae Plagiorchis elegans (Rudolphi, 1802), a parasite of the Golden hamster, Mesocricetus auratus is described. This study is the first ultrastructural study of the spermatozoon of a Plagiorchis, the second of a plagiorchiid species and only the third in the Plagiorchioidea. Previously data on spermatozoon ultrastructure existed only for the plagiorchiid Enodiotrema reductum and the omphalometrid Rubenstrema exasperatum. The mature spermatozoon of P. elegans exhibited the general pattern described in most digenean species, namely two axonemes of the 9 + "1" Trepaxonemata pattern, nucleus, mitochondria, external ornamentation of the plasma membrane, spine-like bodies, and glycogen granules. However, the rather typical expansion of the plasma membrane is not found in P. elegans. Another peculiarity of the spermatozoon of P. elegans is the presence of a structure called thin cytoplasm termination. Spermatozoon ultrastructure of P. elegans is compared with that of E. reductum and R. exasperatum. Spermatozoon of P. elegans conforms to the general pattern described in E. reductum. Thus, this study further expands our knowledge on the spermatozoon ultrastructure among the members of the Plagiorchioidea, one of the most phylogenetically derived groups of the digenea.

  9. Elevated female fecundity as a possible compensatory mechanism in response to trematode infestation in populations of Littorina saxatilis (Olivi).

    Science.gov (United States)

    Granovitch, A I; Yagunova, E B; Maximovich, A N; Sokolova, I M

    2009-07-15

    Co-evolution between parasites and their hosts may lead to changes in the life-history traits of the host that promote sustainability of their populations despite parasite pressure. Such changes are expected to be especially pronounced in the host-parasite systems where parasites cause complete castration of their hosts. We have studied populations of the rough periwinkle, Littorina saxatilis, infested by castrating trematode species, in order to determine whether high infestation levels are associated with a compensatory increase in host fecundity. To test this hypothesis, we determined female fecundity in populations with trematode prevalence spanning from 75% in one population, but remained high and relatively stable in the second population, reflecting its consistently high trematode prevalence (40-65%). These data support the hypothesis that an increase in female fecundity may be a population compensation mechanism in response to heavy trematode infestation in L. saxatilis and suggest the possible involvement of both natural selection and fast (physiological) regulation mechanisms.

  10. Risks for fishborne zoonotic trematodes in tilapia production systems in Guangdong province, China

    DEFF Research Database (Denmark)

    Li, Kang; Clausen, Jesper Hedegaard; Murrell, Kenneth Darwin

    2013-01-01

    Guangdong province is the most important region for tilapia culture in China. However, it is also an endemic region for fishborne zoonotic trematodes (FZT), which pose a risk to human food safety and health. A study was designed to assess the status of trematode parasite infections in tilapia...... risk of spillover of FZT from area sylvatic reservoir hosts, a survey of local wild-caught fish was conducted. Five species of FZT were discovered from a total of 271 wild-caught fish and a mean infection density of 4.0 metacercariae/100 g; FZT discovered included intestinal flukes (Haplorchis spp...

  11. Composição e sazonalidade dos moluscos do alto rio Paraná, Brasil, e sua potencialidade como hospedeiros intermediários de digenéticos - DOI: 10.4025/actascibiolsci.v30i3.5018 Composition and seasonality of mollusks from the upper Paraná river, Brazil, and their potentiality as intermediate hosts for digeneans - DOI: 10.4025/actascibiolsci.v30i3.5018

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    Gilberto Cezar Pavanelli

    2008-10-01

    Full Text Available Este trabalho analisa a composição e a sazonalidade das espécies de moluscos potenciais hospedeiros intermediários de trematódeos digenéticos, bem como fornece informações a respeito das possíveis infecções por diplostomídeos nesta comunidade, em ambientes lênticos da planície de inundação do alto rio Paraná. Foram coletadas e analisadas dez espécies de moluscos, e houve nítida sazonalidade na densidade e abundância dos moluscos, correlacionada significativamente com a temperatura da água. Os maiores valores observados foram entre os meses de novembro de 2002 a fevereiro de 2003. Apenas Biomphalaria peregrina caracterizou-se como hospedeiro para Diplostomidae, pois nesta espécie foram encontradas 32 cercárias de Hysteromorpha triloba em março de 2003.This study analyzes the composition and seasonality of mollusk species as potential intermediate hosts for digenean trematodes, and also supplies information regarding the possible infections by diplostomidae in that community, in lentic environments of the upper Paraná river floodplain. Ten species of mollusks were collected and analyzed, with noticeable seasonality in the density and abundance of mollusks, significantly correlated with water temperature. The highest values observed were in the period between November 2002 and February 2003. Only Biomphalaria peregrina was characterized as a host for diplostomidae, given that 32 cercariae of Hysteromorpha triloba were found in this species in March 2003.

  12. Loss of trematode parthenitae in Planorbella trivolvis (Mollusca: Gastropoda).

    Science.gov (United States)

    Sears, B F; Rohr, J R

    2013-08-01

    Infection by trematode parthenitae (larval, asexual trematodes) has severe consequences for molluscan hosts, resulting in cessation of reproduction and early mortality. Here we present evidence that the freshwater snail Planorbella trivolvis can lose infections by trematode parthenitae. Of 8 P. trivolvis infected by reniferin parthenitae, 6 died within 2 wk, whereas the remaining 2 snails lost their infections within 82 days after initial examination. This phenomenon might suggest that molluscs can resist established trematode infections (i.e., "self-cure") or at least out-survive some trematode parthenitae.

  13. Larval trematodes in freshwater molluscs from the Elbe to Danube rivers (Southeast Germany): before and today.

    Science.gov (United States)

    Faltýnková, Anna; Haas, Wilfried

    2006-10-01

    Studies on life cycles of trematodes have a long tradition in Germany; (Odening 1978) listed a total of 177 trematodes, which can potentially complete their life cycles in German inland waters. However, almost no recent data on the occurrence of larval stages in molluscs are available. Therefore, a survey of trematodes in Southeast Germany was carried out in 2004. A total of 31 species of ten families (29 species of cercariae, seven species of metacercariae, and five species found of both) were found in 311 (4.9%) molluscs of 15 species. The dominant cercariae were Plagiorchis elegans, Echinoparyphium aconiatum, Opisthioglyphe ranae, and Diplostomum pseudospathaceum. Echinoparyphium pseudorecurvatum is reported, for the first time, under its valid scientific name from Germany. In previous studies from the same region, 88 species of cercariae of 16 families were found in 19 species of molluscs (52 cercariae with valid names and 36 not identified to species level). It is proposed that there is still a very similar spectrum of the most common species of cercariae typical for Central Europe as found 20, but also 100-150 years ago.

  14. Digenean parasites of Ciconiiform birds from Argentina Digéneos parásitos de aves Ciconiiformes de Argentina

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    Fabiana B. Drago

    2011-03-01

    Full Text Available The helminthological survey of 13 specimens of 5 ciconiiform species revealed the presence of 10 species of intestinal digeneans: Sphincterodiplostomum musculosum Dubois, 1936 in Tigrisoma lineatum and Ardea alba; Tylodelphys elongata (Lutz, 1928 in T. lineatum; Apharyngostrigea ardearum (Lutz, 1928 and Dolichorchis lacombeensis Lunaschi and Drago, 2006 in Ardea cocoi and Ardea alba; Posthodiplostomum nanum Dubois, 1937 in A. alba and T. lineatum; Ascocotyle diminuta (Stunkard and Haviland, 1924 in A. alba; Petasiger sp.1 in A. cocoi and Paryphostomum segregatum Dietz, 1909, Strigea vaginata (Brandes, 1888 and Petasiger sp. 2 in Coragyps atratus. Syrigma sibilatrix was free of digeneans. The reports of A. ardearum, T. elongata, S. musculosum and D. lacombeensis represent new host records; the other reports are new geographical records. Moreover, the specimens described as Apharyngostrigea brasiliana Szidat, 1929 by Labriola and Suriano (1998 were analyzed and transferred to A. ardearum.El estudio parasitológico de 13 ejemplares pertenecientes a 5 especies de aves Ciconiiformes reveló la presencia de 10 especies de digéneos intestinales: Sphincterodiplostomum musculosum Dubois, 1936 en Tigrisoma lineatum y Ardea alba; Tylodelphys elongata (Lutz, 1928 en T. lineatum; Apharyngostrigea ardearum (Lutz, 1928 y Dolichorchis lacombeensis Lunaschi y Drago, 2006 en Ardea cocoi y A. alba; Posthodiplostomum nanum Dubois, 1937 en A. alba y T. lineatum; Ascocotyle diminuta (Stunkard y Haviland, 1924 en A. alba; Petasiger sp.1 en A. cocoi y Paryphostomum segregatum Dietz, 1909, Strigea vaginata (Brandes, 1888 y Petasiger sp. 2 en Coragyps atratus. Syrigma sibilatrix no se encontró parasitada por digéneos. El presente estudio aporta nuevos registros de hospedadores para A. ardearum, T. elongata, S. musculosum y D. lacombeensis y nuevos registros geográficos para las restantes especies. Además, los organismos descritos como Apharyngostrigea brasiliana

  15. [Expression of genes encoding defense factors in the snail Planorbarius corneus (Gastropoda, Pulmonata) infested with trematodes].

    Science.gov (United States)

    Prokhorova, E E; Tsymbalenko, N V; Ataev, G L

    2010-01-01

    Because many species of gastropods are intermediate hosts for trematodes, these molluscs are often used as model-organisms in the studies of invertebrate immune system. Revealing of the ways in which the defense factors functioning became possible due to the use of the methods of molecular biology. Contemporary molecular methods allow analyzing the defense factors allocations and levels of their expression. We investigated the expression of genes encoding defense factors in gastropods by the example of the snail Planorbarius corneus from water bodies of the Leningrad Oblast under infestation with trematods. The snails naturally infested with the parthenites of trematode species belonging to the families Strigeidae, Notocotylidae, Plagiorchiidae, and Schistosomatida were used as the experimental sample. Uninfested snails were used as a control sample. Several genes encoding the factors, which have been recently found involved in the anti-trematode defense reactions in pulmonates, were chosen, namely fibrinogen-related protein, C-lectin, calcium-binding protein, and cystatin-like protein. The genes' expression was analyzed on total mRNA samples by the reverse transcription with the polymerase chain reaction. It was shown than expression levels of the genes under consideration are different in uninfested snails and in the snails infested with different trematode species. Thus, in the mollusks infested with the parthenites of Cotylurus sp. and Bilharziella polonica, the expression levels of the genes of all factors under study were increased, while in the infested Notocotylus sp. n Plagiorchis sp., only expression levels of C-lectin and cystatin-like protein were increased. Results of the expression analysis confirm the role of hemocytes and cells of hepatopancreas in the production of humoral defense factors. In the snails infested with trematodes, the expression levels of C-lectin and calcium-binding protein genes are increased in haemocytes, while the genes of

  16. The trematodes and cestodes of Sorex araneus L. in Valaam Island (Ladoga Lake, USSR. 1

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    Michael V. Novikov

    1992-01-01

    Full Text Available The trematode and the cestode fauna was examined in 50 specimens of common shrews Sorex araneus L. (Insectivora: Soricidae cillected in Valaam Island, URSS during 1988 and 1989. Two species of Trematoda and seven species of Cestoda were identified; prevalence of infection was as follows: Brachulaemus fulvus (86% , Rubenstrema exasperatum (4% , Hymenolepis scutigera (54% , Neoskrjabinolepis schaldybini (26% , Vigisolepis spinulosa (4% , Choanotaenia crassiscolex (86% , Choanotaenia hepatica (6% , Dilepis undula (2% and Polycercus sp. (2% .

  17. The trematodes and cestodes of Sorex araneus L. in Valaam Island (Ladoga Lake, USSR). 1

    OpenAIRE

    Novikov,Michael V.

    1992-01-01

    The trematode and the cestode fauna was examined in 50 specimens of common shrews Sorex araneus L. (Insectivora: Soricidae) cillected in Valaam Island, URSS during 1988 and 1989. Two species of Trematoda and seven species of Cestoda were identified; prevalence of infection was as follows: Brachulaemus fulvus (86% ), Rubenstrema exasperatum (4% ), Hymenolepis scutigera (54% ), Neoskrjabinolepis schaldybini (26% ), Vigisolepis spinulosa (4% ), Choanotaenia crassiscolex (86% ), Choanotaenia hepa...

  18. Identifikasi Cacing Trematoda dan Gambaran Patologi Ginjal Burung Merpati yang Terinfeksi (IDENTIFICATION AND PATHOLOGICAL FEATURES OF TREMATODE IN PIGEON’S KIDNEY

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    Ana Sahara

    2013-12-01

    Full Text Available This study is conducted to identify species of trematode and its pathological features in pigeons’kidney. Twenty five of Yogyakarta pigeons were examined for trematode infection in kidneys. One ofkidneys was mashed in mortar with a little water, the other was examined for histopathological featuresstained with hematoxyline-eosin.Trematodes found were stained with Schmison ´s Carmine. Seven pigeons(28% were infected by trematode with non significant clinical features. Identification trematodescharacterized by oral sucker, pharynx, testes are slighty diagonal in position, irregular in shape and intracaecal. Ovary pretesticular and vitellaria widespread from anterior ovarium to the posterior body.Histopathological examination showed segment of trematode in the medullary collecting ducts lumen,dilatation, flattening and emptyness of ducts epithelial cells, emptyness, giant cells and dominationmononuclear cell in interstitial tissue, characterizing a granulomatous nephritis. Trematodes foundidentified as Paratanaisia bragai. The trematodes were found in very dilated medullary collecting ductsand caused inflammation in adjacent tissues. Further studies are needed to find out vector of trematodein pigeons .

  19. Sperm ultrastructure of the digenean Aphallus tubarium (Rudolphi, 1819) Poche, 1926 (Platyhelminthes, Cryptogonimidae) intestinal parasite of Dentex dentex (Pisces, Teleostei).

    Science.gov (United States)

    Foata, J; Quilichini, Y; Greani, S; Marchand, B

    2012-02-01

    The ultrastructural organization of the spermatozoon of a cryptogonimid digenean, Aphallus tubarium, a parasite of Dentex dentex, is described. The spermatozoon possesses the elements found in other digeneans: two axonemes with 9+"1" pattern, a mitochondrion, a nucleus, cortical microtubules, external ornamentation and spine-like bodies. However, the mitochondrion appears as a cord with a bulge; this characteristic has never been described in other studied cryptogonimid and in other digeneans except in one lepocreadiid, Holorchis micracanthum. Likewise, the presence of a thin cytoplasm termination in the anterior part of the spermatozoon has never been pointed out in the cryptogonimids.

  20. A survey of didymozoid trematodes of the barracuda Sphyraena obtusata from Kuwait Bay.

    Science.gov (United States)

    Abdul-Salam, J; Sreelatha, B S

    1993-08-01

    Examination of 120 yellow-finned barracudas, Sphyraena obtusata, from Kuwait Bay revealed 8 species of didymozoid trematodes encapsulated in pairs in the tissues. Four species of the didymozoids, Allodidymozoon operculare, Didymocylindrus sp., Didymocystis sp., and Didymocystoides sp., were found in the head region, 3 species, Didymozoon tetragynae, Lepidodidymozoon sinicum and Platocystoides polyaster, in external surfaces and 1 species, Allodidymozoon sp., in stomach wall. The didymozoid species collected constitute new geographic distribution records and occurrence of D. tetragynae and L. sinicum are new host records.

  1. Otitis media and a neck lump--current diagnostic challenges for Paragonimus-like trematode infections.

    Science.gov (United States)

    Schuster, H; Agada, F O; Anderson, A R; Jackson, R S; Blair, D; McGann, H; Kelly, G

    2007-02-01

    A 29 year-old Nigerian studying in the UK presented with a neck lump and otitis media. Paragonimus-like trematode eggs were found in the neck lump aspirate. Morphologically these eggs resembled Paragonimus uterobilateralis or Achillurbainia congolensis. We favoured the diagnosis of achillurbainiasis over extrapulmonary paragonimiasis on the basis of clinical features and because we could not amplify DNA sequences using PCR primers specific for Paragonimus species. We discuss current diagnostic challenges for this rare parasitic infection.

  2. Parasitic worms and their histopathological effects in four sturgeon species from the southwest shores of the Caspian Sea

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Noei

    2016-01-01

    Full Text Available This study conducted to provide the status of parasite communities of four sturgeon species viz. Acipenser stellatus, A. gueldenstaedtii, A. nudiventris, and Huso huso in the southwest of the Caspian Sea and their histopathological effects on the examined fishes. For this purpose a total of 93 individuals of four sturgeon species were caught in two fisheries regions from the southwest of the Caspian Sea (Guilan Province, Iran from March 2010 to May 2011. The histological slides of the infested tissues of the examined fishes were prepared for study of the histopathological effects of the parasites. Classical epidemiological variables, including mean intensity, prevalence, abundance and dominance were calculated for overall samples, grouped by season, geographical region, and sex. Five worm species, including two nematodes (Cucullanus   sphaerocephalus and Eustrongylides excisus larvae, one cestode (Bothrimonus fallax, one acanthocephalans (Leptorhynchoide plagicephalus and one digenean trematode (Skrjabinopsolus   semiarmatus were found in examined sturgeons and their histopathological effects on the fish tissues were assessed. Based on the results, the diversity of the parasites (including freshwater ones in the southern part of the Caspian Sea have decreased since the time of the first study in 1972. This may be related to unfavorable conditions in freshwater ecosystems.

  3. Influence of site, season, silvering stage, and length on the parasites of the European eel Anguilla anguilla in two Mediterranean coastal lagoons of the island of Corsica, France using indicator species method.

    Science.gov (United States)

    Filippi, Jean-José; Quilichini, Yann; Foata, Joséphine; Marchand, Bernard

    2013-08-01

    The parasites of 425 European eels, Anguilla anguilla, were studied between 2009 and 2012 in two Mediterranean coastal lagoons of the island of Corsica, France. An indicator value (IndVal) method was used for analysis, which combines measures of fidelity and specificity. Because of its resilience to detect changes in abundance, IndVal is an effective ecological bioindicator. The IndVal method demonstrated that site, season, silvering stage, and length could influence the occurrence of parasite species in European eel. A randomization test identified ten parasite species as having a significant indicator value for site (lagoons differed principally in salinity: oligohaline to polyhaline for the Biguglia lagoon and polyhaline to euhaline for the Urbino lagoon; the digeneans Bucephalus anguillae and Lecithochirium musculus, the cestodes Bothriocephalus claviceps, Proteocephalus macrocephalus, and larvae of Myzophyllobothrium sp., the nematodes Anguillicoloides crassus, and encysted larvae of Contracaecum sp., the acanthocephalan Acanthocephaloides incrassatus, the monogenean Pseudodactyogyrus anguillae, and the copepod Ergasilus gibbus); one parasite species for the spring season (the acanthocephalan A. incrassatus); six parasite species for silvering stage (yellow, pre-silver, silver; the trematodes B. anguillae and Deropristis inflata, encysted larvae of the nematode Contracaecum sp., the acanthocephalan A. incrassatus, the monogenean P. anguillae, and the copepod E. gibbus); and three parasite species for some of the five length classes (the cestode P. macrocephalus, encysted larvae of the nematode Contracaecum sp., and the monogenean P. anguillae). Data for species composition and infection levels should help to improve the management of parasitism in the populations of European eels.

  4. Trematode diversity in freshwater fishes of the Globe I: 'Old World'.

    Science.gov (United States)

    Scholz, Tomáš; Besprozvannykh, Vladimir V; Boutorina, Tamara E; Choudhury, Anindo; Cribb, Thomas H; Ermolenko, Alexey V; Faltýnková, Anna; Shedko, Marina B; Shimazu, Takeshi; Smit, Nico J

    2016-03-01

    In this paper, we review, continent by continent, the trematode fauna of freshwater fishes of the 'Old World', a vast area consisting of the Palaearctic, Ethiopian, Oriental and Australasian zoogeographical regions. Knowledge of this fauna is highly uneven and clearly incomplete for almost all regions, sometimes dramatically so. Although the biggest problem remains the completion of the 'first pass' of alpha taxonomy, there are in addition great problems relating to biogeography and elucidation of life-cycles. For the latter, molecular data, i.e. matching DNA sequences of larval stages and corresponding adults, may represent a powerful tool that should be used in future studies. Another challenging problem represents the existence of cryptic species and, in particular, considerable decrease of experts in taxonomy and life-cycles of trematodes.

  5. Taken to the limit--Is desiccation stress causing precocious encystment of trematode parasites in snails?

    Science.gov (United States)

    O'Dwyer, Katie; Poulin, Robert

    2015-12-01

    When hosts experience environmental stress, the quantity and quality of resources they provide for parasites may be diminished, and host longevity may be decreased. Under stress, parasites may adopt alternative strategies to avoid fitness reductions. Trematode parasites typically have complex life cycles, involving asexual reproduction in a gastropod first intermediate host. A rare phenomenon, briefly mentioned in the literature, and termed 'precocious encystment' involves the next stage in the parasites' life cycle (metacercarial cyst) forming within the preceding stage (redia), while still inside the snail. In the trematode Parorchis sp. NZ using rocky shore snails exposed to long periods outside water, we hypothesised that this might be an adaptive strategy against desiccation, preventing parasite emergence from the snail. To test this, we first investigated the effect of prolonged desiccation on the survival of two species of high intertidal snails. Secondly, we measured the reproductive output (cercarial production) of the parasite under wet and dry conditions. Finally, we quantified the influence of desiccation stress on the occurrence of precocious encystment. Snail mortality was higher under dry conditions, indicating stress, and it was somewhat exacerbated for infected snails. Parasite reproductive output differed between wet and dry conditions, with parasites of snails kept in dry conditions producing more cercariae when placed in water. Little variation was observed in the occurrence of precocious encystment, although some subtle patterns emerged. Given the stresses associated with living in high intertidal environments, we discuss precocious encystment as a possible stress response in this trematode parasite.

  6. Population dinamics of Lymnaea rubiginosa in rice fields and its infection with larvae of trematodes

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    Suhardono

    2000-12-01

    Full Text Available Field of irrigated rice paddy was the most suitable habitat as breeding site of snail Lymnaea rubiginosa, the intermadiate host of Fasciola gigantica and other trematodes. Fluctuations in the population of fresh water snail, L. rubiginosa in irrigated rice fields and their infection with L. rubiginosa and other trematodes were studied in five villages in the subdistrict of Surade, provivine of West Java. Snail were sampled based on time collection (half man hour each site of collection. The samples of the snails were further counted and examined for the presence of larval trematodes. The result indicated that snails died during the dry season except those in persistent aquatic refuges such as streams and springs. Surviving snails recolonised rice fields near villages by passive transfer with water from refuges early in the wet season. Some recolonosation may also have resulted from haching of snail eggs deposited in habitats which had not been dried for more than a few weeks. Recolonisation with snails of further rice fields from a village occurred during the later period of the wet season. No snail infected with F. gigantica was found in the distance of more than 200 m from a village. Snail with the highest prevalence of infection occurred in rice fields which received effluent from a cattle pen were fertilised with bovine faeces. Each snail was only infected with one species of tramatodes. Infection with echinostone larvae was most common.

  7. [Demonstration of life cycle with four obligatory hosts of the Hemiurid Trematodes].

    Science.gov (United States)

    Kechemir, N

    1978-01-01

    Research on the transmission of Hemiurid Trematode Halipegus ovocaudatus in experimental and natural conditions demonstrates the following: --the miracidium grows into a sporocyst producing rediae in the Mollusc Planorbis planorbis; -- the cystophorous cercariae become mesocercariae in the hemocoele of Copepodes or finally Ostracodes when swallowed; -- the mesocercariae become matacercariae in the mesenteron of larval Odonates (Zygoptera and Anisoptera) when these larvae swallow the Crustacea; -- the metacercariae become become adults in the Amphibial Rana ridibundal perezi which feeds on dragonflies. The four hosts (Mollusc -- Crustacean -- Odonat -- Amphibian) are obligatory in the life cycle for it is impossible to infect the Insects directly with the cecariae or the frog (tadpoles as well as adults) with the mesocercariae. The different stages of the life cycle of H. oveocaudatus aredescribed and the mode of the transmission is compared with the other species of Halipegus and with the Trematodes in general. The adaptative value of the lengthening of the cycle is discussed from the point of view of the conquest of terrestrial hosts by the Hemiurid Trematodes.

  8. Current status of food-borne trematode infections.

    Science.gov (United States)

    Toledo, R; Esteban, J G; Fried, B

    2012-08-01

    Food-borne trematodiases constitute an important group of the most neglected tropical diseases, not only in terms of research funding, but also in the public media. The Trematoda class contains a great number of species that infect humans and are recognized as the causative agents of disease. The biological cycle, geographical distribution, and epidemiology of most of these trematode species have been well characterized. Traditionally, these infections were limited, for the most part, in populations living in low-income countries, particularly in Southeast Asia, and were associated with poverty. However, the geographical limits and the population at risk are currently expanding and changing in relation to factors such as growing international markets, improved transportation systems, and demographic changes. The diagnosis of these diseases is based on parasitological techniques and only a limited number of drugs are currently available for treatment, most of which are unspecific. Therefore, in-depth studies are urgently needed in order to clarify the current epidemiology of these helminth infections and to identify new and specific targets for both effective diagnosis and treatment. In this review, we describe the biology, medical and epidemiological features, and current treatment and diagnostic tools of the main groups of flukes and the corresponding diseases.

  9. Digeneans of cetaceans: taxonomy, evolutionary history and host specificity.

    OpenAIRE

    Fraija Fernández, Natalia

    2016-01-01

    Parasitism is an extremely successful lifestyle among animals. In fact, every free-living organism is believed to harbour at least a parasite species, and cetaceans are not the exception. Host-parasite systems offer a suitable model for studying systematics, evolution, biogeography and ecology because the evolutionary fate of parasites is linked to that of their hosts. In particular, present-day associations between cetaceans and their parasites have been shaped by unique historical events. T...

  10. Brackish-water submergence of the common periwinkle, Littorina littorea, and its digenean parasites in the Baltic Sea and in the Kattegat

    Science.gov (United States)

    Lauckner, G.

    1984-03-01

    North Sea and Baltic Sea populations of Littorina littorea differ with respect to their vertical distribution. In the North Sea L. littorea is strictly intertidal while in the Baltic Sea maximum population densities occur in the sublittoral. Levels of infestation with larval digenetic trematodes diminish qualitatively (number of species recorded) and quantitatively (number of hosts infested) with decreasing salinity. Both the host and two parasite species — Cryptocotyle lingua and Microphallus pygmaeus — display ‘brackish-water submergence’ under conditions of reduced surface salinity.

  11. Physiological and pathological changes in the eastern oyster Crassostrea virginica infested with the trematode Bucephalus sp. and exposed to the toxic dinoflagellate Alexandrium fundyense.

    Science.gov (United States)

    Lassudrie, Malwenn; Wikfors, Gary H; Sunila, Inke; Alix, Jennifer H; Dixon, Mark S; Combot, Doriane; Soudant, Philippe; Fabioux, Caroline; Hégaret, Hélène

    2015-03-01

    Effects of experimental exposure to Alexandrium fundyense, a Paralytic Shellfish Toxin (PST) producer known to affect bivalve physiological condition, upon eastern oysters, Crassostrea virginica with a variable natural infestation of the digenetic trematode Bucephalus sp. were determined. After a three-week exposure to cultured A. fundyense or to a control algal treatment with a non-toxic dinoflagellate, adult oysters were assessed for a suite of variables: histopathological condition, hematological variables (total and differential hemocyte counts, morphology), hemocyte functions (Reactive Oxygen Species (ROS) production and mitochondrial membrane potential), and expression in gills of genes involved in immune responses and cellular protection (MnSOD, CAT, GPX, MT-IV, galectin CvGal) or suspected to be (Dominin, Segon). By comparing individual oysters infested heavily with Bucephalus sp. and uninfested individuals, we found altered gonad and digestive gland tissue and an inflammatory response (increased hemocyte concentration in circulating hemolymph and hemocyte infiltrations in tissues) associated with trematode infestation. Exposure to A. fundyense led to a higher weighted prevalence of infection by the protozoan parasite Perkinsus marinus, responsible for Dermo disease. Additionally, exposure to A. fundyense in trematode-infested oysters was associated with the highest prevalence of P. marinus infection. These observations suggest that the development of P. marinus infection was advanced by A. fundyense exposure, and that, in trematode-infested oysters, P. marinus risk of infection was higher when exposed to A. fundyense. These effects were associated with suppression of the inflammatory response to trematode infestation by A. fundyense exposure. Additionally, the combination of trematode infestation and A. fundyense exposure caused degeneration of adductor muscle fibers, suggesting alteration of valve movements and catch state, which could increase

  12. Trematodes of the Great Barrier Reef, Australia: emerging patterns of diversity and richness in coral reef fishes.

    Science.gov (United States)

    Cribb, Thomas H; Bott, Nathan J; Bray, Rodney A; McNamara, Marissa K A; Miller, Terrence L; Nolan, Mathew J; Cutmore, Scott C

    2014-10-15

    The Great Barrier Reef holds the richest array of marine life found anywhere in Australia, including a diverse and fascinating parasite fauna. Members of one group, the trematodes, occur as sexually mature adult worms in almost all Great Barrier Reef bony fish species. Although the first reports of these parasites were made 100 years ago, the fauna has been studied systematically for only the last 25 years. When the fauna was last reviewed in 1994 there were 94 species known from the Great Barrier Reef and it was predicted that there might be 2,270 in total. There are now 326 species reported for the region, suggesting that we are in a much improved position to make an accurate prediction of true trematode richness. Here we review the current state of knowledge of the fauna and the ways in which our understanding of this fascinating group is changing. Our best estimate of the true richness is now a range, 1,100-1,800 species. However there remains considerable scope for even these figures to be incorrect given that fewer than one-third of the fish species of the region have been examined for trematodes. Our goal is a comprehensive characterisation of this fauna, and we outline what work needs to be done to achieve this and discuss whether this goal is practically achievable or philosophically justifiable.

  13. Cryptic diversity and patterns of host specificity in trematode flatworms.

    Science.gov (United States)

    Hayward, Alexander

    2010-07-01

    The widespread utilization of molecular markers has revealed that a broad spectrum of taxa contain sets of morphologically cryptic, but genetically distinct lineages (Bickford et al. 2007). The identification of cryptic taxa is important as an accurate appreciation of diversity is crucial for a proper understanding of evolutionary and ecological processes. An example is the study of host specificity in parasitic taxa, where an apparent generalist may be found to contain a complex of several more specific species (Smith et al. 2006). Host specificity is a key life history trait that varies greatly among parasites (Poulin & Keeney 2007). While some can exploit a wide range of hosts, others are confined to just a single species. Access to additional hosts increases the resources available to a parasite. However, physiological or ecological constraints can restrict the extension of host range. Furthermore, there may be a trade-off between relaxed specificity and performance: generalism can decrease a parasites ability to adapt to each individual host species, and increase exposure to competition from other parasites (Poulin 1998). Despite the central role that host specificity plays in parasite life history, relatively little is known about how host range is determined in natural systems, and data from field studies are required to evaluate among competing ideas. In this issue, an exciting paper by Locke et al. (2010) makes a valuable contribution toward the understanding of host specificity in an important group of trematode flatworms. Using molecular methods, Locke et al. reveal an almost four-fold increase in the appreciated diversity of their focal group. In combination with a large and elegant sampling design this allows them to accurately assess host specificity for each taxon, and thus draw key insights into the factors that control host range in a dominant parasite group.

  14. Epidemiology of cercarial stage of trematodes in freshwater snails from Chiang Mai province, Thailand

    Institute of Scientific and Technical Information of China (English)

    Thapana Chontananarth; Chalobol Wongsawad

    2013-01-01

    Objective: To investigate the epidemiological situation of cercarial trematodes infection in freshwater snails from different water resources in Chiang Mai province, Thailand. Methods:The snail specimens were collected from 13 districts of Chiang Mai province during April 2008 to February 2012. The prevalence of cercarial infection in snails was investigated using the crushing method. The drawing was done with the help of a camera lucida for the morphological study. Results:A total of 2 479 snail individuals were collected and classified into 7 families, 11 genera, and 14 species, Among them, 8 snails species were found to be infected with an overall prevalence of 17.27% (428/2 479), which infected with nine groups of cercariae;gymnocephalous cercaria, strigea cercaria, megalurous cercaria, monostome cercaria, parapleurolophocercous cercaria (Haplorchis cercaria), pleurolophocercous cercaria, furcocercous cercaria (Transversotrema cercaria), xiphidiocercaria, and virgulate cercaria. The parapleurolophocercous cercaria was found to be the dominant type among the cercarial infection in the snails (64.25%). Conclusions:The various species of snails found in the research location act as the intermediate hosts for the high prevalence of parasitic infection of many species of mammals. This work will provide new information on both the distribution and first intermediate host of trematodes.

  15. Molecular investigation of Neorickettsia risticii in trematodes and snails in a region with serological evidence of this agent in horses, state of Rio de Janeiro

    Directory of Open Access Journals (Sweden)

    R.L. Costa

    Full Text Available ABSTRACT In Brazil, some studies have indicated that Neorickettsia risticii circulates in horses, but it is unclear which are the possible intermediate vectors of this bacterium in the country. The aim of this study was to use molecular techniques in order to analyze the presence of N. risticii in snails and larval stages of trematodes in farms in a region with a history of seroreactive horses towards this bacterium, in Rio de Janeiro, Brazil. Convenience sampling was used in the studied region. The collected snails were exposed to incandescent light (60W for 2-4 hours in order to investigate trematodes in larval forms. Deoxyribonucleic acid (DNA was extracted from snail tissue and trematode. Real-time PCR (qPCR technique was used to investigate the presence of a 16S rRNA gene fragment of N. risticii. Snail specimens (n=410 were collected from 11 horse-breeding farms, and the following species were identified: Melanoides tuberculata, Pomacea sp., Biomphalaria tenagophila, Physa acuta, Drepanotrema anatinum and Biomphalaria straminea. Only 3.17% (n=13/410 of the collected snails were infected by trematodes. The cercariae obtained from these snails were classified as Megalourous cercariae, Pleurolophocercus cercariae and Furcocercous cercariae. There was no amplification of the target DNA of N. risticii in the snail and trematode samples tested by qPCR. Based on these data, the transmission of N. risticii by trematodes using these snail species in this region does not appear to occur or occurs at very low rates. Thus, further studies are needed in order to clarify which species of invertebrate hosts are infected by this bacterium and potentially participate in the transmission chain of equine neorickettsiosis in the state of Rio de Janeiro, Brazil.

  16. Accacoelium contortum (Trematoda: Accacoeliidae) a trematode living as a monogenean: morphological and pathological implications.

    Science.gov (United States)

    Ahuir-Baraja, Ana Elena; Padrós, Francesc; Palacios-Abella, Jose Francisco; Raga, Juan Antonio; Montero, Francisco Esteban

    2015-10-15

    Accacoelium contortum (Rudolphi, 1819) Monticelli, 1893 is a frequent but poorly known trematode found on gills, pharynx and digestive tract of the ocean sunfish Mola mola (L.). Although the morphology of A. contortum agrees with that of a typical endoparasitic trematode, with two relatively small suckers and no large holdfasts, this parasite is normally ectoparasitic. The main objective of this paper is to explore this peculiar host-parasite relationship. A total of 106 ocean sunfish were examined for the presence of A. contortum. The oropharyngeal chamber (gills and pharynx) and the digestive tract were analysed. As the previous descriptions of this species seem to be based on contracted specimens, for the morphological study the parasites were killed using two methods: with hot 70% ethanol (with relaxed bodies) and with 70% ethanol at room temperature (with contracted bodies). For histological studies, samples from fresh fish with parasitised left gills, pharynx and digestive tract were fixed in buffered 10% formalin. For molecular studies the 18S, 28S and ITS-2 sequences were provided and compared with the available data in GenBank®. New information on the morphology of A. contortum and on the parasite-related response and pathological alterations in the host are given. New diagnostic traits for some structures are provided: e.g. tegumental papillae of the forebody with apical digitiform swellings and mouth surrounded by a circum-oral crown of simple papillae. The length of the ventral sucker peduncle and the position of the vitellarium were found to be associated with the contraction degree of the specimen. Immature individuals of this species are described for the first time. An intense proliferative inflammatory response of host gill and pharynx epithelium at the host-parasite interface was detected and parasites became partially covered by overgrowths of host tissues. The induction of prominent histological alterations associated with A. contortum seems to

  17. Larval stages of digenetic trematodes in Melanopsis praemorsa snails from freshwater bodies in Palestine

    Institute of Scientific and Technical Information of China (English)

    Sami Bdir; Ghaleb Adwan

    2011-01-01

    Objective: To detect the species of larval trematodes (cercariae) in Melanopsis praemorsa snails from 5 different fresh water bodies in Palestine. Methods: A total of 1 880 Melanopsis praemorsa snails were collected from different fresh water bodies in Palestine from October, 2008 to November, 2010. Cercariae in Melanopsis praemorsa snails were obtained by lighting and crushing methods. The behavior of cercariae was observed using a dissecting microscope. Results: Three different species of larval trematodes were identified from Melanopsis praemorsa snails collected only from Al-Bathan fresh water body, while snails from other water bodies were not infected. These species were microcercous cercaria, xiphidiocercaria and brevifurcate lophocercous cercaria. These cercariae called Cercaria melanopsi palestinia I, Cercaria melanopsi palestinia II and Cercaria melanopsi palestinia III have not been described before from this snail in Palestine. The infection rate of Melanopsis praemorsa collected from Al-Bathan fresh water body was 5.7%, while the overall infection rate of snails collected from all fresh water bodies was 4.3%. Details are presented on the morphology and behavior of the cercariae as well as their development within the snail. Conclusions: These results have been recorded for the first time and these cercariae may be of medical and veterinary importance.

  18. A review on the molecular characterization of digenean parasites using molecular markers with special reference to ITS region

    Directory of Open Access Journals (Sweden)

    Choudhary K.

    2015-09-01

    Full Text Available The rDNA region of eukaryotes has the immense potential to resolve the evolutionary and phylogeny problems using molecular markers. As evident from the present review, ITS region data is considered for interpretation of inter and intra-specific variations of 136 studies of 33 families including 78 genus and 114 species affecting individuals worldwide. Along with ITS-1 and ITS-2 region in 29 studies 18S region, in 38 studies 28S region and in 43 studies mitochondrial genes (COI and NDI were also analyzed. Three new genera (Allobilharzia gen. nov., Caulanus gen. nov., and Latuterus gen. nov. and 49 new species were discovered. Only 47 studies expressed variations at intra-specific and inter-specific level in complete ITS region, ITS-1 and ITS-2 rDNA sequences due to differences in nucleotide positions. According to the findings ITS region is more reliable and precise marker for demarcation and identification of species in combination of other DNA markers. Major studies were involved around the parasites of families Fasciolidae, Schistosomatidae, Opisthorchidae, Paragonimidae and Paramphistomidae, Clinostomidae, Diplostomidae, Haploporidae, among others infecting humans, farm animals, birds, fishes, reptiles and amphibians on the clinical basis. In future, molecular and bioinformatics aspects based on genetic variations will lead to explore the untouched areas of trematodes.

  19. Risks for fishborne zoonotic trematodes in tilapia production systems in Guangdong province, China.

    Science.gov (United States)

    Li, Kang; Clausen, Jesper Hedegaard; Murrell, K Darwin; Liu, Liping; Dalsgaard, Anders

    2013-11-15

    Guangdong province is the most important region for tilapia culture in China. However, it is also an endemic region for fishborne zoonotic trematodes (FZT), which pose a risk to human food safety and health. A study was designed to assess the status of trematode parasite infections in tilapia aquaculture systems as an indicator of potential risks from FZT associated with consumption of tilapia. Tilapia from nursery and grow-out ponds were sampled from monoculture, polyculture and integrated aquaculture systems. The results from 388 tilapia examined revealed a very low prevalence (1.5%) of trematode infections (Heterophyidae and Echinostomatidae). Integrated systems using animal manure and latrine wastes as fertilizer did not show a higher prevalence of FZT. Because it was not clear whether the low risk of infection was attributable to existing effective pond management practices or a low risk of spillover of FZT from area sylvatic reservoir hosts, a survey of local wild-caught fish was conducted. Five species of FZT were discovered from a total of 271 wild-caught fish and a mean infection density of 4.0 metacercariae/100g; FZT discovered included intestinal flukes (Haplorchis spp., Procerovum varium, and Metagonimus spp.) and metacercariae tentatively identified as Clonorchis sinenesis. The common occurrence of FZT in wild-caught fish suggests that the presence of FZT in local wild animal reservoirs is substantial, and that although the current aquaculture management systems for tilapia are generally effective in preventing transmission of these parasites into tilapia production systems, the improvement of pond management practices and biosecurity must be maintained at a high level.

  20. Morphological Characteristics and Phylogenetic Trends of Trematode Cercariae in Freshwater Snails from Nakhon Nayok Province, Thailand

    Science.gov (United States)

    Chontananarth, Thapana; Tejangkura, Thanawan; Wetchasart, Napat; Chimburut, Cherdchay

    2017-01-01

    The prevalence of cercarial infection in freshwater snails and their evolutionary trends were studied in Nakhon Nayok province, Thailand. A total of 2,869 individual snails were examined for parasitic infections. The results showed that 12 snail species were found to host larval stages of trematodes with an overall prevalence of 4.7%. The infected specimens included 7 types at the cercarial stage; cercariae, megalurous cercariae, echinostome cercariae, furcocercous cercariae, parapleurolophocercous cercariae, virgulate cercariae, and xiphidiocercariae. Regarding molecular identification, ITS2 sequence data of each larval trematode were analyzed, and a dendrogram was constructed using the neighbor-joining method with 10,000 replicates. The dendrogram was separated into 6 clades (order/family), including Echinostomatida/Echinostomatidae, Echinostomatida/Philophthalmidae, Opisthorchiida/Heterophyidae, Plagiorchiida/Prosthogonimidae, Plagiorchiida/Lecithodendriidae, and Strigeatida/Cyathocotylidae. These findings were used to confirm morphological characteristics and evolutionary trends of each type of cercariae discovered in Nakhon Nayok province. Furthermore, this investigation confirmed that the ITS2 data of cercariae could be used to study on phylogenetic relationships or to determine classification of this species at order and/or family level when possible. PMID:28285506

  1. Morphological Characteristics and Phylogenetic Trends of Trematode Cercariae in Freshwater Snails from Nakhon Nayok Province, Thailand.

    Science.gov (United States)

    Chontananarth, Thapana; Tejangkura, Thanawan; Wetchasart, Napat; Chimburut, Cherdchay

    2017-02-01

    The prevalence of cercarial infection in freshwater snails and their evolutionary trends were studied in Nakhon Nayok province, Thailand. A total of 2,869 individual snails were examined for parasitic infections. The results showed that 12 snail species were found to host larval stages of trematodes with an overall prevalence of 4.7%. The infected specimens included 7 types at the cercarial stage; cercariae, megalurous cercariae, echinostome cercariae, furcocercous cercariae, parapleurolophocercous cercariae, virgulate cercariae, and xiphidiocercariae. Regarding molecular identification, ITS2 sequence data of each larval trematode were analyzed, and a dendrogram was constructed using the neighbor-joining method with 10,000 replicates. The dendrogram was separated into 6 clades (order/family), including Echinostomatida/Echinostomatidae, Echinostomatida/Philophthalmidae, Opisthorchiida/Heterophyidae, Plagiorchiida/Prosthogonimidae, Plagiorchiida/Lecithodendriidae, and Strigeatida/Cyathocotylidae. These findings were used to confirm morphological characteristics and evolutionary trends of each type of cercariae discovered in Nakhon Nayok province. Furthermore, this investigation confirmed that the ITS2 data of cercariae could be used to study on phylogenetic relationships or to determine classification of this species at order and/or family level when possible.

  2. Chronobiology of trematode cercarial emergence: from data recovery to epidemiological, ecological and evolutionary implications.

    Science.gov (United States)

    Théron, André

    2015-04-01

    One major challenge for parasites with complex cycles consists to succeed in the transmission from one host to the next host. To maximize the probability of encountering the right host, numerous trematode species have selected various emergence rhythms occurring during the escape of the short-lived cercariae from the mollusc host. Cercarial shedding patterns are beautiful examples of adaptation of the parasite for a successful rendezvous with its subsequent host. In this review, after an analysis of the technical and statistical aspects specific to such studies, we compile the knowledge and unresolved issues we have about the synchronization of these rhythms, their genetic support and the role of the host physiology or activity. We are also interested on how cercarial rhythmicity influences cercarial densities in waters of transmission sites and then the risk of host infection in case of schistosomiasis. Ecological significance of the inter- and intra-specific diversity of these rhythms is emphasized as well as the evolutionary implication of new chronotypes resulting from the capture of new host species and promoting reproductive isolation and alloxenic speciation. Currently, genome sequence data now available for some trematodes such as the schistosomes provide an unprecedented resource for new research approaches that should contribute identification of the genes and mechanisms involved in determining the cercarial shedding rhythms observed.

  3. Pathology and first report of natural eye infection with the trematode Philophthalmus gralli (Digenea, Philophthalmidae) in Tinamus major (Tinamiformes, Tinamidae), Costa Rica.

    Science.gov (United States)

    Rojas, Diana; Soto, Carmen; Rojas, Alicia

    2013-12-01

    The eye-fluke Philophthalmus gralli (Philophthalmidae Looss, 1899) was found in six birds known as great tinamous (Tinamus major) reared in a wild animal shelter located in Alajuela, Costa Rica. The birds presented conjunctival hyperemia, blepharitis, anorexia and weakness. Some of them suffered from unilateral blindness and ocular loss. After morphometric analysis, the specimens showed characteristics compatible with the digenean trematode P. gralli. The clinical signs of infection were resolved by manual removal of the adults, treatment with praziquantel and relocation into an environment without a natural water source. In order to determine if an ongoing cycle of this pathogen was present in the shelter, the habitat of the birds was inspected for the presence of infected intermediate hosts and contaminated water and objects. It was found that the snails Melanoides tuberculata acted as the intermediate host, and reared the infectious stages toward other animals, as shown by the reproduction of ocular philophthalmiasis in chickens artificially infected with excysted metacercaria. Moreover, three out of every ten snails found in the place were infected with rediae of P. gralli, raising the possibility of the dispersion of the parasite into new environments as well as the imminent zoonotic risk. The finding of P. gralli in Costa Rica is the first official report in Central America.

  4. Types of trematodes infecting freshwater snails found in irrigation canals in the East Nile locality, Khartoum, Sudan

    DEFF Research Database (Denmark)

    Mohammed, Nidal A. I.; Madsen, Henry; Ahmed, Abdel Aziz A. R. M.

    2016-01-01

    Background: The planorbid freshwater snails of the two genera, Biomphalaria and Bulinus -have been vigorously studied due to the role they play as intermediate hosts of schistosomiasis. In Sudan specifically, most studies have focused on the chemical and ecological control of the two genera......, but few studies have looked at their biological control. This study explored the coexistence of other species of freshwater snails and the two genera along with their trematode infections in relation to a number of environmental factors in the East Nile locality, Khartoum state, Sudan. Methods: Freshwater...... snails from irrigation canals (abueshreens) were sampled monthly from January 2004 to December 2005. The snails were examined for trematode infections by cercarial emergence immediately after collection and then weekly for an additional four weeks to allow for the maturation of prepatent infections...

  5. Do the historical biogeography and evolutionary history of the digenean Margotrema spp. across central Mexico mirror those of their freshwater fish hosts (Goodeinae?

    Directory of Open Access Journals (Sweden)

    Andrés Martínez-Aquino

    Full Text Available Host-parasite systems provide an ideal platform to study evolution at different levels, including codivergence in a historical biogeography context. In this study we aim to describe biogeographic and codivergent patterns and associated processes of the Goodeinae freshwater fish and their digenean parasite (Margotrema spp. over the last 6.5 Ma (million years, identifying the main factors (host and/or hydrogeomorphology that influenced the evolution of Margotrema. We obtained a species tree for Margotrema spp. using DNA sequence data from mitochondrial and nuclear molecular markers (COI and ITS1, respectively and performed molecular dating to discern divergence events within the genus. The dispersal-extinction-cladogenesis (DEC model was used to describe the historical biogeography of digeneans and applied to cophylogenetic analyses of Margotrema and their goodeine hosts. Our results showed that the evolutionary history of Margotrema has been shaped in close association with its geographic context, especially with the geological history of central Mexico during the Pleistocene. Host-specificity has been established at three levels of historical association: a Species-Species, represented by Xenotaenia resolanae-M. resolanae exclusively found in the Cuzalapa River Basin; b Species-Lineage, represented by Characodon audax-M. bravoae Lineage II, exclusive to the Upper and Middle Mezquital River Basin, and c Tribe-Lineage, including two instances of historical associations among parasites and hosts at the taxonomical level of tribe, one represented by Ilyodontini-M. bravoae Lineage I (distributed across the Ayuquila and Balsas River Basins, and another comprised of Girardinichthyini/Chapalichthyini-M. bravoae Lineage III, found only in the Lerma River Basin. We show that the evolutionary history of the parasites is, on several occasions, in agreement with the phylogenetic and biogeographic history of their hosts. A series of biogeographic and host

  6. Do the historical biogeography and evolutionary history of the digenean Margotrema spp. across central Mexico mirror those of their freshwater fish hosts (Goodeinae)?

    Science.gov (United States)

    Martínez-Aquino, Andrés; Ceccarelli, Fadia Sara; Eguiarte, Luis E; Vázquez-Domínguez, Ella; de León, Gerardo Pérez-Ponce

    2014-01-01

    Host-parasite systems provide an ideal platform to study evolution at different levels, including codivergence in a historical biogeography context. In this study we aim to describe biogeographic and codivergent patterns and associated processes of the Goodeinae freshwater fish and their digenean parasite (Margotrema spp.) over the last 6.5 Ma (million years), identifying the main factors (host and/or hydrogeomorphology) that influenced the evolution of Margotrema. We obtained a species tree for Margotrema spp. using DNA sequence data from mitochondrial and nuclear molecular markers (COI and ITS1, respectively) and performed molecular dating to discern divergence events within the genus. The dispersal-extinction-cladogenesis (DEC) model was used to describe the historical biogeography of digeneans and applied to cophylogenetic analyses of Margotrema and their goodeine hosts. Our results showed that the evolutionary history of Margotrema has been shaped in close association with its geographic context, especially with the geological history of central Mexico during the Pleistocene. Host-specificity has been established at three levels of historical association: a) Species-Species, represented by Xenotaenia resolanae-M. resolanae exclusively found in the Cuzalapa River Basin; b) Species-Lineage, represented by Characodon audax-M. bravoae Lineage II, exclusive to the Upper and Middle Mezquital River Basin, and c) Tribe-Lineage, including two instances of historical associations among parasites and hosts at the taxonomical level of tribe, one represented by Ilyodontini-M. bravoae Lineage I (distributed across the Ayuquila and Balsas River Basins), and another comprised of Girardinichthyini/Chapalichthyini-M. bravoae Lineage III, found only in the Lerma River Basin. We show that the evolutionary history of the parasites is, on several occasions, in agreement with the phylogenetic and biogeographic history of their hosts. A series of biogeographic and host

  7. Are sick individuals weak competitors? Competitive ability of snails parasitized by a gigantism-inducing trematode.

    Science.gov (United States)

    Seppälä, Otto; Karvonen, Anssi; Kuosa, Marja; Haataja, Maarit; Jokela, Jukka

    2013-01-01

    Parasitized individuals are often expected to be poor competitors because they are weakened by infections. Many trematode species, however, although extensively exploiting their mollusc hosts, also induce gigantism (increased host size) by diverting host resources towards growth instead of reproduction. In such systems, alternatively to reduced competitive ability due to negative effects of parasitism on host performance, larger size could allow more efficient resource acquisition and thus increase the relative competitive ability of host individuals. We addressed this hypothesis by testing the effect of a trematode parasite Diplostomum pseudospathaceum on the competitive ability of its snail host Lymnaea stagnalis. We experimentally examined the growth of snails kept in pairs in relation to their infection status and intensity of resource competition (i.e. food availability). We found that parasitized snails grew faster and their reproduction was reduced compared to unparasitized individuals indicating parasite-induced gigantism. However, growth of the snails was faster when competing with parasitized individuals compared to unparasitized snails indicating reduced competitive ability due to parasitism. The latter effect, however, was relatively weak suggesting that the effects of the parasite on snail physiology may partly override each other in determining competitive ability.

  8. Are sick individuals weak competitors? Competitive ability of snails parasitized by a gigantism-inducing trematode.

    Directory of Open Access Journals (Sweden)

    Otto Seppälä

    Full Text Available Parasitized individuals are often expected to be poor competitors because they are weakened by infections. Many trematode species, however, although extensively exploiting their mollusc hosts, also induce gigantism (increased host size by diverting host resources towards growth instead of reproduction. In such systems, alternatively to reduced competitive ability due to negative effects of parasitism on host performance, larger size could allow more efficient resource acquisition and thus increase the relative competitive ability of host individuals. We addressed this hypothesis by testing the effect of a trematode parasite Diplostomum pseudospathaceum on the competitive ability of its snail host Lymnaea stagnalis. We experimentally examined the growth of snails kept in pairs in relation to their infection status and intensity of resource competition (i.e. food availability. We found that parasitized snails grew faster and their reproduction was reduced compared to unparasitized individuals indicating parasite-induced gigantism. However, growth of the snails was faster when competing with parasitized individuals compared to unparasitized snails indicating reduced competitive ability due to parasitism. The latter effect, however, was relatively weak suggesting that the effects of the parasite on snail physiology may partly override each other in determining competitive ability.

  9. Infection by Paramphistomidae trematodes in cattle from two agricultural regions in NW Uruguay and NW Spain.

    Science.gov (United States)

    Sanchís, J; Sánchez-Andrade, R; Macchi, M I; Piñeiro, P; Suárez, J L; Cazapal-Monteiro, C; Maldini, G; Venzal, J M; Paz-Silva, A; Arias, M S

    2013-01-16

    The analysis of infection by Paramphistomidae trematodes was conducted in two agricultural regions with different knowledge on this parasitosis. Faecal and blood samples were collected from 374 cattle in Salto (NW Uruguay) where there is a lack of information about paramphistomosis. A total of 429 cattle from Galicia (NW Spain), an area with previous records of infection by gastric flukes, were sampled. Diagnostics of trematodosis was developed by using a copromicroscopic probe and an ELISA with excretory/secretory antigens collected from adult Calicophoron daubneyi (Paramphistomidae) specimens. Results were evaluated according intrinsic and extrinsic factors. In the Uruguay, the percentage of cattle passing Paramphistomidae-eggs by faeces was 7% (95% Confidence Interval 5, 10). A significantly higher prevalence of paramphistomosis in the Hereford × Angus cattle (OR=3.5) was recorded, as observed for the oldest ruminants (>3.5 years). An overall seroprevalence of 29% (25, 34) was obtained by ELISA, with the highest values in the Friesians (OR=3), the youngest bovines (Uruguay, especially by improving their management to avoid exposure to the gastric trematode. Further studies are in progress for identifying the species of Paramphistomidae affecting ruminants in Uruguay.

  10. Detection of spirorchiid trematodes in gastropod tissues by polymerase chain reaction: preliminary identification of an intermediate host of Learedius learedi.

    Science.gov (United States)

    Stacy, Brian A; Frankovich, Thomas; Greiner, Ellis; Alleman, A Rick; Herbst, Lawrence H; Klein, Paul; Bolten, Alan; McIntosh, Antoinette; Jacobson, Elliott R

    2010-08-01

    Marine spirorchiid trematodes are associated with morbidity and mortality in sea turtles worldwide. The intermediate hosts remain unknown, and discovery efforts are hindered by the large number and great diversity of potential hosts within sea turtle habitats, as well the potential for low prevalence and overdispersion. A high-throughput DNA extraction and polymerase chain reaction-based method was developed to detect the internal transcribed spacer 2 (ITS2) region of the ribosomal gene of 2 spirorchiid genera, Learedius and Hapalotrema , within pooled samples of gastropod tissues. A model system consisting of freshwater snail ( Pomacea bridgesii ) tissues and DNA extracts spiked with adult Learedius learedi and known quantities of spirorchiid DNA was used to develop and test the technique. Threshold of detection was found to be equivalent to an early prepatent infection within 1.5 g of gastropod tissue. This technique was used to screen approximately 25 species of marine gastropods at a captive facility where green turtles ( Chelonia mydas ) become infected by L. learedi . The parasite was detected in a sample of knobby keyhole limpet ( Fissurella nodosa ), thus providing the first evidence of an intermediate host for a marine spirorchiid trematode. This technique has many potential applications in trematode life cycle discovery studies.

  11. Mantle-shell complex reactions elicited by digenean metacercariae in Gaimardia trapesina (Bivalvia: Gaimardiidae) from the Southwestern Atlantic Ocean and Magellan Strait.

    Science.gov (United States)

    Ituarte, C F; Cremonte, F; Deferrari, G

    2001-12-20

    The host response to 3 different larval digeneans affecting Southwestern Atlantic and Magellanic populations of the bivalve Gaimardia trapesina (Lamarck, 1819) (Gaimardiidae) is described. Unencysted metacercariae of 2 species of Gymnophallidae and 1 species of Lepocreadiidae co-exist in the peripheral and general extrapallial spaces. Differences in host responses to stimuli generated by each parasite are described. Infections by Gymnophallidae gen. sp. 1 metacercariae elicit a mantle-shell complex reaction involving both alteration of the mantle epithelium (hyperplasia and metaplasia) and calcium carbonate deposition to form an incomplete calcareous covering of single larvae, comprising individual crystallites in an organic matrix. The calcareous covering covers only the posterior two-thirds of the larval body, having its anterior end free in the extrapallial space, which ensures survival of the larvae. The peculiar features of the host response result from a successful process of adjustment to the parasite's life cycle. Metacercariae of Gymnophallidae gen. sp. 2 occur in one or more small groups of up to 30 individuals, either in the general or in the peripheral extrapallial spaces. The outer mantle reaction includes hyperplasia and metaplasia of the epithelium adjacent to the larvae. Deposition of calcium carbonate did not occur. Lepocreadiidae gen. sp. metacercariae were observed exclusively in the general extrapallial space lodged in single shallow pits whose shape fit the parasite's body shape and size. In simultaneous infections, metacercariae of Gymnophallidae and Lepocreadiidae elicited different responses in an individual, which suggests that each parasitic entity involves a different stimulus to the host.

  12. [New species of tremstodes from Indian Ocean and Red Sea fishes].

    Science.gov (United States)

    Parukhin, A M

    1979-01-01

    On the basis of the material collected in the Red Sea and the Indian Ocean four new species of trematodes are described: Bucephalopsis pseni sp. n., Diploproctodaeum chelonodoni sp. n., Bucephalus neoscombropsi sp. n., Phyllodistomum sobolevi sp. n. Anatomical and morphological characteristics of the above species as well as original figures of the trematodes are given, their taxonomic position is discussed.

  13. [A study of parasitic trematodes of Littorina saxatilis and their impact on this mollusc (author's transl)].

    Science.gov (United States)

    Combescot-Lang, C

    1976-01-01

    A monthly study of populations of Littorina saxatilis (mollusc, gasteropod) very strongly parasited has allowed to establish relations between the said mollusc and some parasite trematodes which live in it. A selection of animals was done in two stations of the Roscoff region (Finistere). A total of more than 1.000 individuals have been examined in each station. Eleven species of cercairs have been spotted. It has appeared that the Microphallus similis was the most represented: 79,86% of the total. This rate of parasitism does not change much throughout the year. The populations of molluscs strongly parasited by Microphallus similis show an important castration. A double association of cercairs remains rare but is yet possible. It appears that aged individuals are the most parasited. It seems that there would be a growth of parasites more important in females than in males.

  14. Review: Bucephalus minimus, a deleterious trematode parasite of cockles Cerastoderma spp.

    Science.gov (United States)

    Magalhães, L; Freitas, R; de Montaudouin, X

    2015-04-01

    Trematodes are the most prevalent and abundant macroparasites in coastal waters. They display a complex life cycle with alternation of free-living and parasitic stages generally involving three host species. The most deleterious stage is in the first intermediate host (a mollusc) where the parasite penetrates as miracidium larvae and asexually multiplicates in sporocysts/rediae to provide cercariae larvae. However, due to basic low prevalence in ecosystems, this system remains difficult to study. Taking the example of the cockle (Cerastoderma edule), an exploited bivalve along North-Eastern Atlantic coasts, and Bucephalus minimus, its most prevalent parasite as first intermediate host, we summarised the 51 most relevant papers (1887-2015). Besides, a 16-year monthly monitoring was performed at Banc d'Arguin (Atlantic coast of France), and allowed to obtain a sufficient number of infected cockles (276 out of 5,420 individuals) in order to provide new information concerning this parasite/host system. Sporocysts (diameter 80-500 μm) and developing cercariae (length 300-500 μm) are not visible before cockle reaches 16-mm shell length and then prevalence increases with host size. Seasonality of infection was not observed but variation of prevalence was significant among years and negatively correlated to the temperature of the former year, which could correspond to the period of infection by miracidium. Seven other species of trematode were identified in cockles as second intermediate host. For six of them, metacercariae abundance per individual was 2 to 12 folds higher in B. minimus-infected cockles, exacerbating the potential negative impact on host. From the parasite point of view, metacercariae can be considered as hitchhikers, taking advantage of the abnormal migration of B. minimus-infected cockles to the sediment surface where they become more vulnerable to predators that are also the final hosts of many of these parasites.

  15. Molecular confirmation of trematodes in the snail intermediate hosts from Ratchaburi Province, Thailand

    Directory of Open Access Journals (Sweden)

    Sothorn Anucherngchai

    2017-05-01

    Full Text Available Objective: To analyze the prevalence of trematode infections in the snails intermediate host Tarebia granifera and Melanoides tuberculata collected from Ratchaburi Province by a molecular approach in order to construct a dendrogram to identify species at the cercarial stage. Methods: Specimens were collected from nine districts located in Ratchaburi Province using the stratified sampling method. The samples were examined for cercarial infection using the crushing method. All specimens were amplified by region of internal transcribed spacer 2 (ITS2 based on the PCR technique, and the sequence data were aligned in order to construct the dendrogram by maximum likelihood with 10 000 bootstrap replicates. Results: Five cercarial types were observed comprising parapleurolophocercous cercaria, xiphidiocercaria, megarulous cercaria, furcocercous cercaria and transversotrema cercaria. The overall prevalence of cercarial infection was found to be 7.92% (63 / 795. The parapleurolophocercous cercaria was found in the highest level of prevalence followed by xiphidiocercaria, megarulous cercaria, furcocercous cercaria and transversotrema cercaria, respectively. The parapleurolophocercous cercaria samples were identified and separated into Haplorchis taichui and Haplorchis pumilio, while xiphidiocercaria were identified as Lecithodendriidae and megarulous cercaria were identified as Philophthalmus. The dendrogram separated the cercariae into five groups, which were comprised of parapleurolophocercous cercaria, xiphidiocercaria, megarulous cercaria, furcocercous cercaria and transversotrema cercaria using the sequence of Angiostrongylus cantonensis as an out-group. Conclusions: This is the first study to report on the prevalence of cercarial infection in Ratchaburi Province, Thailand. The high prevalence of cercariae was revealed by the infection in Tarebia granifera and Melanoides tuberculata. Thus, the sequence data of ITS2 can be used to investigate the

  16. [Infection of the mollusc Littorina saxatilis with parthenites of trematodes and their impact on a shell form: analysis of populations inhabiting the littoral coast of the White Sea].

    Science.gov (United States)

    Kaliberdina, M V; Granovich, A I

    2003-01-01

    12 rocky shore populations of Littorina saxatilis from three islands of Chupa Inlet (Kandalaksha Bay, White Sea) were examined for infection with trematodes. Morphometric characters (6 indexes of the shell and aperture shape) of molluscs were investigated for all these populations. Exposed and sheltered sites were considered at every island and high and low littoral samples were fulfilled at every site. Seven species of trematodes, Podocotyle atomon, Cryptocotyle lingua, Renicola sp., Himasthla sp., Microphallus piriformes, M. pygmaeus, M. pseudopygmaeus, were found. Uneven distribution of trematodes was confirmed by log-linear analysis. Sheltered populations of L. saxatilis have the greater infection prevalence than exposed ones. This is due to the heavy infection with M. piriformes and M. pygmaeus. The prevalences by these trematodes are up to 52.97% and 27.16% respectively in sheltered populations of the host. The prevalence of M. piriformes tend to be higher at the upper shore level of sheltered sites. In a contrast, the prevalence of M. pygmaeus is significantly higher at the low part of such sites. Factor analysis shows a significant association of the indices of L. saxatilis shell shape with three factors. The first one is associated with the "elongation" of a shell and reveals L. saxatilis from the exposed rocky shore to be more elongated than the molluscs from sheltered sites. The second one is connected with the "aperture shape" index. There is an association of this factor with the shore level position of samples. The third factor reflects the affect of trematodes on the shell shape. The molluscs infected with M. piriformes show "elongated" shell shape and relatively smaller aperture. Shall peculiarities of the hosts infected with M. piriformes and M. pygmaeus are somewhat different. The results of the factor analysis is justified by the series of analysis of variances on the values of shell indices (MANOVA) according to the factors "exposure", "shore

  17. Gymnophallid digenean Parvatrema duboisi uses Manila clam as the first and second intermediate host.

    Science.gov (United States)

    Yanagida, Tetsuya; Shirakashi, Sho; Iwaki, Takashi; Ikushima, Noboru; Ogawa, Kazuo

    2009-09-01

    To identify the metacercariae of a gymnophallid trematode in the Manila clam Ruditapes philippinarum from the Ariake Sea, experimental infection and molecular analysis were conducted. Based on the morphology of adult worms obtained from experimentally infected mice, the parasite was identified as Parvatrema duboisi. Comparison of internal transcribed spacer (ITS) region of ribosomal DNA (rDNA) sequences for metacercariae and sporocysts from Manila clams and adult worms collected from wild wigeon Anas penelope showed minor differences ranging from 0 to 0.8%. These data strongly suggest that in the Ariake Sea, the parasite has a lifecycle using the Manila clam as the first and second intermediate hosts and wigeon as the definitive host.

  18. Analysis of trait mean and variability versus temperature in trematode cercariae: is there scope for adaptation to global warming?

    Science.gov (United States)

    Studer, A; Poulin, R

    2014-05-01

    The potential of species for evolutionary adaptation in the context of global climate change has recently come under scrutiny. Estimates of phenotypic variation in biological traits may prove valuable for identifying species, or groups of species, with greater or lower potential for evolutionary adaptation, as this variation, when heritable, represents the basis for natural selection. Assuming that measures of trait variability reflect the evolutionary potential of these traits, we conducted an analysis across trematode species to determine the potential of these parasites as a group to adapt to increasing temperatures. Firstly, we assessed how the mean number of infective stages (cercariae) emerging from infected snail hosts as well as the survival and infectivity of cercariae are related to temperature. Secondly and importantly in the context of evolutionary potential, we assessed how coefficients of variation for these traits are related to temperature, in both cases controlling for other factors such as habitat, acclimatisation, latitude and type of target host. With increasing temperature, an optimum curve was found for mean output and mean infectivity, and a linear decrease for survival of cercariae. For coefficients of variation, temperature was only an important predictor in the case of cercarial output, where results indicated that there is, however, no evidence for limited trait variation at the higher temperature range. No directional trend was found for either variation of survival or infectivity. These results, characterising general patterns among trematodes, suggest that all three traits considered may have potential to change through adaptive evolution.

  19. Snails and trematode infection after Indian Ocean tsunami in Phang-Nga Province, southern Thailand.

    Science.gov (United States)

    Sri-Aroon, Pusadee; Chusongsang, Phiraphol; Chusongsang, Yupa; Pornpimol, Surinthwong; Butraporn, Piyarat; Lohachit, Chantima

    2010-01-01

    The tsunami and non-tsunami affected areas of Takua Pa District, Phang-Nga Province were investigated for fresh- and brackish-water snails that transmit human parasitic diseases during 2006 and 2007. Among 46 snail species found, 17 species of 8 families were freshwater snails, 28 species of another 7 families were brackish-water snails, and 1 species was a land snail. Of these species, 11 freshwater snails, 4 brackish-water snails and 1 land snail were of medical importance. The fresh-water snails were Pomacea canaliculata, Pila angelica, P. gracilis, P. polita, Filopaludina (S.) martensi, F. (F.) s. polygramma, Melanoides tuberculata, Indoplanorbis exuxtus, Radix rubiginosa, Helicorbis umbilicalis, Gyraulus convexiusculus. Four brackish-water snails were Cerithidea cingulata, C. djadjarensis, C. alata, Sermyla riqueti and Achatina fulica was the land snail. I. exutus, M. tuberculata and F. (F.) s. polygramma harbored Xiphidio, Microcercus, Furocercus, Echinostome cercariae, and cercaria without eyespots or tail with hair. Three species of brackish-water snails, Cerithidia cingulata, C. djadjariensis, and C. alata presented with 6 types of trematode cercariae and rediae. Knowledge of medically important snails and their parasitic diseases, and prevention were given to Takua Pa people by poster, pamphlets and broadcasting through community radio.

  20. Distribution of trematodes in snails in ponds at integrated small-scale aquaculture farms

    NARCIS (Netherlands)

    Boerlage, A.S.; Graat, E.A.M.; Verreth, J.A.J.; Jong, de M.C.M.

    2013-01-01

    In integrated small-scale aquaculture farming, animal and human excreta maybe used as fish feed and pond fertilizer, thereby enhancing transmission of fish-borne zoonotic trematodes (FZTs) from final hosts, like humans, pigs and chickens, to snails. Areas within a pond could vary in trematode egg-lo

  1. Host diversity and latitude drive the trematode diversity patterns in the European freshwater fauna

    DEFF Research Database (Denmark)

    Thieltges, David W.; Hof, Christian; Dehling, D. Matthias;

    2011-01-01

    biogeographical regions in Europe from the Limnofauna Europaea and used multiple regression analyses to test for correlations between the diversity of definitive (vertebrates) or first intermediate (gastropods) hosts and that of trematodes, and for latitudinal gradients in trematode diversity. In particular, we...

  2. Host diversity and latitude drive trematode diversity patterns in the European freshwater fauna

    NARCIS (Netherlands)

    Thieltges, D.W.; Hof, C.; Dehling, D.M.; Brändle, M.; Brändl, R.; Poulin, R.

    2011-01-01

    Aim We investigated the relationship between host and parasite diversity as well as latitudinal gradients in parasite diversity on a continental scale in European freshwater trematodes.
    Location European freshwaters.
    Methods We extracted distributional data for 564 freshwater trematodes across

  3. Host diversity and latitude drive trematode diversity patterns in the European freshwater fauna

    NARCIS (Netherlands)

    Thieltges, D.W.; Hof, C.; Dehling, D.M.; Brändle, M.; Brändl, R.; Poulin, R.

    2011-01-01

    Aim We investigated the relationship between host and parasite diversity as well as latitudinal gradients in parasite diversity on a continental scale in European freshwater trematodes.
    Location European freshwaters.
    Methods We extracted distributional data for 564 freshwater trematodes across

  4. Experimental infection dynamics: using immunosuppression and in vivo parasite tracking to understand host resistance in an amphibian-trematode system.

    Science.gov (United States)

    LaFonte, Bryan E; Johnson, Pieter T J

    2013-10-01

    Although naturally occurring hosts often exhibit pronounced differences in infection and pathology, the relative importance of factors associated with host life history and immunity in explaining such patterns often remains speculative. Research in eco-immunology highlights the trade-offs between host physiology and immunity, for which natural variations in disease susceptibility offer a valuable platform to test predictions within this framework. Here, we combined use of a novel, in vivo assay for tracking parasite fate and an experimental manipulation of host immune function (via chronic corticosterone exposure) to assess the role of host immunity in regulating susceptibility of amphibian hosts to three larval trematodes: Ribeiroia ondatrae, Echinostoma trivolvis and Alaria sp. 2. Results from the in vivo parasite-tracking assay revealed marked differences in initial parasite penetration and subsequent host clearance. Relative to infections in a highly susceptible species (Pseudacris regilla), the virulent trematode R. ondatrae was -25% less successful at penetrating larvae of three hylid frog species and was cleared > 45(×) faster, such that all parasites were rapidly cleared from hylid hosts over 72 h following a Weibull distribution. Immune suppression of Hyla versicolor sharply reduced this resistance and increased infection of all three trematodes by 67 to 190%, with particularly strong increases for R. ondatrae. Diminished resistance correlated with a 62% decrease in circulating eosinophils. Correspondingly, 10 days after corticosterone exposures ended, infections declined dramatically while eosinophil levels returned to normal. In light of ongoing declines and deformities in amphibian populations, these findings have application potential for mitigating disease-driven effects.

  5. Factors determining parasite community richness and species composition in black snook Centropomus nigrescens (Centropomidae) from coastal lagoons in Guerrero, Mexico.

    Science.gov (United States)

    Violante-González, Juan; Mendoza-Franco, Edgar F; Rojas-Herrera, Agustín; Gil Guerrero, Salvador

    2010-06-01

    Species richness and composition were determined for parasite communities in the black snook Centropomus nigrescens collected from five coastal lagoons in the Guerrero state, Mexico. A total of 354 fish were collected between December 2007 and November 2008. Twenty-four species of parasite were identified: 2 monogeneans, 12 digeneans, 4 acanthocephalans, 1 cestode, 4 nematodes, and 1 pentastomid. The communities consisted mainly of autogenic parasites, and all were dominated by the digenean Paracrytogonimus yamagutii. Community species composition was similar among lagoons, although the influence of local conditions prevented them from being identical. Host traits such as predator feeding habits, body size, and vagility contributed to parasite community structure and species composition.

  6. Trematodes indicate animal biodiversity in the chilean intertidal and Lake Tanganyika

    Science.gov (United States)

    Hechinger, R.F.; Lafferty, K.D.; Kuris, A.M.

    2008-01-01

    Trematode communities in populations of estuarine snails can reflect surrounding animal diversity, abundance, and trophic interactions. We know less about the potential for trematodes to serve as bioindicators in other habitats. Here, we reanalyze data from 2 published studies concerning trematodes, 1 in the Chilean rocky intertidal zone and the other from the East African rift lake, Lake Tanganyika. Our analyses indicate that trematodes are more common in protected areas and that in both habitats they are directly and positively related to surrounding host abundance. This further supports the notion that trematodes in first intermediate hosts can serve as bioindicators of the condition of free-living animal communities in diverse ecosystems. ?? American Society of Parasitologists 2008.

  7. Histological analysis of trematodes in Dreissena polymorpha: their location, pathogenicity, and distinguishing morphological characteristics.

    Science.gov (United States)

    Laruelle, Franck; Molloy, Daniel P; Roitman, Vitali A

    2002-10-01

    Four families of trematodes were observed in histological sections during a 1992-1997 investigation of the parasites of zebra mussels Dreissena polymorpha. These included Aspidogastridae, i.e., Aspidogaster, Echinostomatidae, Bucephalidae, i.e., Bucephalus polymorphus, and Gorgoderidae, i.e., Phyllodistomumfolium. This article describes the precise location of these trematodes in the tissues of D. polymorpha, provides graphic evidence of their effect on the organs they inhabit, and highlights the distinguishing morphological characteristics. Evidence of defense reaction of host to trematode infection, i.e., encapsulation of Aspidogaster and nacrezation of B. polymorphus, is also presented and is the first such report for zebra mussels. The histological photomicrographs included represent the first comprehensive series published on trematode infection of zebra mussels. These images, in conjunction with the morphological descriptions presented, should assist researchers in identifying the 4 major trematode taxa that they are likely to encounter in the tissue sections of zebra mussels.

  8. 广东滩涂经济鱼类寄生吸虫Ⅵ.独睾科二新种记述(复殖目)%STUDIES ON THE DIGENETIC TREMATODES OF SHALLOW SEA FISHES FROM GUANGDONG PROVINCE,CHINA Ⅵ. DESCRIPTIONS OF TWO NEW SPECIES*(DIGENEA)

    Institute of Scientific and Technical Information of China (English)

    吴金英; 吕军仪; 陈志胜

    1999-01-01

    This paper is the sixth in a series dealing with the digenetic trematodes of shallow sea fishes from Huidong County,Guangdong Province,China.The two new species,one belongs to the genus Elliptobursa of subfamily Pseudoproctotrematinae,Monorchiidae and the other to the genus Lasiotocus of subfamily Lasiotocinae,Monorchiidae.%本文对广东滩涂经济鱼类寄生复殖吸虫独睾科Monorchiidae Odhner,1911中的两新种分别进行详细的描述,其中细长椭囊吸虫Elliptobursa attenuatus sp.nov.作为拟原穴亚科Pseudoproctotrematinae Elliptobursa属的新种,巨穴孤睾吸虫Lasiotocus macrotrema sp.nov.作为孤睾亚科Lasiotocinae,Lasiotocus属的新种.细长椭囊吸虫Elliptobursa attenuatus sp.nov.具独睾科,拟原穴亚科的形态特征.虫体小型,略呈长形,体前端稍狭细,体后部呈圆筒形,体表光滑无刺.口吸盘位于虫体腹面亚端位.前咽存在;咽中等发达;两肠支末端伸达卵巢的中部水平处.腹吸盘圆盘状,位于虫体前1/3处的后缘,腹吸盘相等或略大于口吸盘.睾丸单个,略分叶,位于体后半部,阴茎囊发达,位于体前1/3部分的后半部.阴茎囊内包含有内贮精囊、前列腺部、前列腺细胞、前列腺囊和阴茎.外贮精囊存在.受精囊和劳氏管缺.卵巢卵球形,位于睾丸之前.卵黄腺一对,呈滤泡圆球状,分布于卵巢的左右侧,子宫占据从腹吸盘至精巢前部的纵轴线区域.雌性生殖孔开口于端器官,端器官呈僧帽状,有微棘,排泄囊位于体末端至睾丸前缘,呈囊袋状,排泄孔开口于虫体末端.巨穴孤睾吸虫Lasiotocus macrotrema sp.nov.具有独睾科、独睾亚科的形态特征.虫体小型且丰满,略呈椭圆形,体表光滑无眼点.口吸盘漏斗状,腹端位,发达.咽发达;食道短;两肠支末端膨大,伸达精巢的中部水平.腹吸盘发达,口吸盘和腹吸盘相对身体比率较大.睾丸单个,卵圆形,位于体末端附近,具外贮精囊,阴茎囊发达,包含有

  9. Physiology and lipid metabolism of Littorina saxatilis infected with trematodes.

    Science.gov (United States)

    Arakelova, Katherine S; Chebotareva, Marina A; Zabelinskii, Stanislav A

    2004-09-08

    Physiological and biochemical alterations in Littorina saxatilis infected with larval trematodes were investigated and compared with the metabolism of non-parasitized snails. Oxygen consumption rates of infected snails differed from those of non-infected controls in medium sized individuals (30 to 130 mg) but not in very large infected individuals (> 200 mg). Small snails (0.5 to 8.5 mg) were seldom infected by parasites, and this size-class consisted only of non-infected specimens. The specific oxygen consumption rate of infected snails was not dependent on their mass and remained constant over the size ranges investigated. Alterations in the snail metabolism appeared to be connected to injuries to digestive gland tissues caused by the parasites. The glycogen concentration and fatty acids of neutral lipids and phospholipids in the digestive gland were determined. Infected snails differed from uninfected snails in the complete absence of glycogen in digestive gland and had proportionally higher quantities of eicosenoic (20:1) acid in the total phospholipids. It remains unclear whether infection by trematodes activates enzymes in the snail's digestive gland to synthesize eicosenoic (20:1) acid, or whether the sporocysts themselves possess these enzymes. The role of phospholipid fatty acids in the regulation and maintenance of the parasite's metabolism is briefly considered. Biochemical alterations observed in the fatty acid composition may have an adaptive significance, by helping to stabilize the host-parasite system.

  10. Variable infection of stream salamanders in the southern Appalachians by the trematode Metagonimoides oregonensis (family: Heterophyidae).

    Science.gov (United States)

    Wyderko, Jennie A; Benfield, Ernest F; Maerz, John C; Cecala, Kristen C; Belden, Lisa K

    2015-08-01

    Many factors contribute to parasites varying in host specificity and distribution among potential hosts. Metagonimoides oregonensis is a digenetic trematode that uses stream-dwelling plethodontid salamanders as second intermediate hosts in the Eastern US. We completed a field survey to identify which stream salamander species, at a regional level, are most likely to be important for transmission to raccoon definitive hosts. We surveyed six plethodontid species (N = 289 salamanders) from 23 Appalachian headwater sites in North Carolina: Desmognathus quadramaculatus (n = 69), Eurycea wilderae (n = 160), Desmognathus ocoee (n = 31), Desmognathus monticola (n = 3), Eurycea guttolineata (n = 7), and Gyrinophilus porphyriticus (n = 19). We found infection in all species except D. monticola. Further analysis focused on comparing infection in the two most abundant species, D. quadramaculatus and E. wilderae. We found that D. quadramaculatus had significantly higher infection prevalence and intensity, probably due to a longer aquatic larval period and larger body sizes and thus greater cumulative exposure to the parasite.

  11. Host quality and spatial patterning in infections of the Eastern mudsnail (Ilyanassa obsoleta) by two trematodes (Himasthla quissetensis and Zoogonus rubellus).

    Science.gov (United States)

    Rossiter, Wayne; Sukhdeo, Michael V K

    2012-04-01

    Several studies have suggested that the fitness of a parasite can be directly impacted by the quality of its host. In such cases, selective pressures could act to funnel parasites towards the highest-quality hosts in a population. The results of this study demonstrate that snail host quality is strongly correlated with spatial patterning in trematode infections and that habitat type is the underlying driver for both of these variables. Two trematodes (Himasthla quissetensis and Zoogonus rubellus) with very different life cycles assume the same spatial infection pattern in populations of the first intermediate host (Ilyanassa obsoleta) in coastal marsh habitats. Infected snails are disproportionately recovered from intertidal panne habitats, which offer more hospitable environs for snails than do adjacent habitats (intertidal creeks, coastal flats, and subtidal creeks), in terms of protection from turbulence and wave action, as well as the availability of food stuffs. Snails in intertidal panne habitats are of higher quality when assessed in terms of average size-specific mass, growth rate, and fecundity. In mark-recapture experiments, snails frequently dispersed into intertidal pannes but were never observed leaving them. In addition, field experiments demonstrate that snails confined to intertidal panne habitats are disproportionately infected by both trematode species, relative to conspecifics confined to adjacent habitats. Laboratory experiments show that infected snails suffer significant energetic losses and consume more than uninfected conspecifics, suggesting that infected snails in intertidal pannes may survive better than in adjacent habitats. We speculate that 1 possible mechanism for the observed patterns is that the life cycles of both trematode species allows them to contact the highest-quality snails in this marsh ecosystem.

  12. Potential schistosome-vector snails and associated trematodes in ricefields of Corrients province, Argentina: preliminary results

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    Alejandra Rumi

    1990-09-01

    Full Text Available Considering the possibility of introduction of schistosomiasis mansoni into Argentina as a consequence of dam construction on the Rio De La Plata basin, preliminary studies have been carried out on agrosystems such as ricefields in Corrientes province with the following purposes: 1 to survey and estimate the relative abundance of planorbids and identify potential vector species; 2 to identify environmental factors capable of influencing Biomphalaria population dynamics; and 3 to find out snail-parasite associations and estimate snail infection rates in order to detect possible competitive interactions between larval stages of native trematodes that could be used in biological control of Schistosoma mansoni. Three potential schistosome vectors were detected in ricefields, namely Biomphalaria straminea, B. tenagophila and B. peregrina, although B. orbignyi, a species refractory to infection with S. mansoni, proved the most frequent and abundant. Positive correlations (P0.05 was found in total iron, phosphates (SRP, pH and soil granulometry. Echinocercariae developed from rediae and belonging to Petasiger sp., Paryphostomum sp., and other undetermined species were found.

  13. Molecular identification of larval trematode in intermediate hosts from Chiang Mai, Thailand.

    Science.gov (United States)

    Chuboon, Suksan; Wongsawad, Chalobol

    2009-11-01

    Snail and fish intermediate hosts were collected from rice fields in 3 districts; Mueang, Mae Taeng and Mae Rim of Chiang Mai Province during April-July 2008. For identification of larval trematode infection, standard (cracked for snail and enzymatically digested for fish) and molecular methods were performed. The results showed that three types of cercariae were found, pleurolophocercus, cotylocercous, and echinostome among 4 species of snail with a prevalence of 29, 23 and 3% respectively. Melanoides tuberculata snail was the most susceptible host for cercariae infection. Four species of metacercariae, Haplorchis taichui, Stellantchasmus falcatus, Haplorchoides sp and Centrocestus caninus, were found with a prevalence of 67, 25, 60 and 20%, respectively. The Siamese mud carp (Henicorhynchus siamensis) was the most susceptible fish host for H. taichui, and half- beaked fish (Dermogenys pusillus) for S. falcatus metacercariae infection, whereas Haplorchoides sp and C. caninus were concomitantly found in Puntius brevis. HAT-RAPD profile confirmed that pleurolophocercus cercariae found in Melanoides tuberculata from Mae Taeng District belonged to H. taichui and in Tarebia granifera from Mueang District were S. falcatus.

  14. Environmental Epidemiology of Intestinal Schistosomiasis in Uganda: Population Dynamics of Biomphalaria (Gastropoda: Planorbidae in Lake Albert and Lake Victoria with Observations on Natural Infections with Digenetic Trematodes

    Directory of Open Access Journals (Sweden)

    Candia Rowel

    2015-01-01

    Full Text Available This study documented the population dynamics of Biomphalaria and associated natural infections with digenetic trematodes, along the shores of Lake Albert and Lake Victoria, recording local physicochemical factors. Over a two-and-a-half-year study period with monthly sampling, physicochemical factors were measured at 12 survey sites and all freshwater snails were collected. Retained Biomphalaria were subsequently monitored in laboratory aquaria for shedding trematode cercariae, which were classified as either human infective (Schistosoma mansoni or nonhuman infective. The population dynamics of Biomphalaria differed by location and by lake and had positive relationship with pH (P<0.001 in both lakes and negative relationship with conductivity (P=0.04 in Lake Albert. Of the Biomphalaria collected in Lake Albert N=6,183, 8.9% were infected with digenetic trematodes of which 15.8% were shedding S. mansoni cercariae and 84.2% with nonhuman infective cercariae. In Lake Victoria, 2.1% of collected Biomphalaria  N=13,172 were infected with digenetic trematodes with 13.9% shedding S. mansoni cercariae, 85.7% shedding nonhuman infective cercariae, and 0.4% of infected snails shedding both types of cercariae. Upon morphological identification, species of Biomphalaria infected included B. sudanica, B. pfeifferi, and B. stanleyi in Lake Albert and B. sudanica, B. pfeifferi, and B. choanomphala in Lake Victoria. The study found the physicochemical factors that influenced Biomphalaria population and infections. The number and extent of snails shedding S. mansoni cercariae illustrate the high risk of transmission within these lake settings. For better control of this disease, greater effort should be placed on reducing environmental contamination by improvement of local water sanitation and hygiene.

  15. Environmental Epidemiology of Intestinal Schistosomiasis in Uganda: Population Dynamics of Biomphalaria (Gastropoda: Planorbidae) in Lake Albert and Lake Victoria with Observations on Natural Infections with Digenetic Trematodes

    Science.gov (United States)

    Rowel, Candia; Fred, Besigye; Sousa-Figueiredo, Jose C.; Kabatereine, Narcis B.; Stothard, J. Russell

    2015-01-01

    This study documented the population dynamics of Biomphalaria and associated natural infections with digenetic trematodes, along the shores of Lake Albert and Lake Victoria, recording local physicochemical factors. Over a two-and-a-half-year study period with monthly sampling, physicochemical factors were measured at 12 survey sites and all freshwater snails were collected. Retained Biomphalaria were subsequently monitored in laboratory aquaria for shedding trematode cercariae, which were classified as either human infective (Schistosoma mansoni) or nonhuman infective. The population dynamics of Biomphalaria differed by location and by lake and had positive relationship with pH (P < 0.001) in both lakes and negative relationship with conductivity (P = 0.04) in Lake Albert. Of the Biomphalaria collected in Lake Albert (N = 6,183), 8.9% were infected with digenetic trematodes of which 15.8% were shedding S. mansoni cercariae and 84.2% with nonhuman infective cercariae. In Lake Victoria, 2.1% of collected Biomphalaria  (N = 13,172) were infected with digenetic trematodes with 13.9% shedding S. mansoni cercariae, 85.7% shedding nonhuman infective cercariae, and 0.4% of infected snails shedding both types of cercariae. Upon morphological identification, species of Biomphalaria infected included B. sudanica, B. pfeifferi, and B. stanleyi in Lake Albert and B. sudanica, B. pfeifferi, and B. choanomphala in Lake Victoria. The study found the physicochemical factors that influenced Biomphalaria population and infections. The number and extent of snails shedding S. mansoni cercariae illustrate the high risk of transmission within these lake settings. For better control of this disease, greater effort should be placed on reducing environmental contamination by improvement of local water sanitation and hygiene. PMID:25705680

  16. Modelling climate change impact on the spatial distribution of fresh water snails hosting trematodes in Zimbabwe.

    Science.gov (United States)

    Pedersen, Ulrik B; Stendel, Martin; Midzi, Nicholas; Mduluza, Takafira; Soko, White; Stensgaard, Anna-Sofie; Vennervald, Birgitte J; Mukaratirwa, Samson; Kristensen, Thomas K

    2014-12-12

    Freshwater snails are intermediate hosts for a number of trematodes of which some are of medical and veterinary importance. The trematodes rely on specific species of snails to complete their life cycle; hence the ecology of the snails is a key element in transmission of the parasites. More than 200 million people are infected with schistosomes of which 95% live in sub-Saharan Africa and many more are living in areas where transmission is on-going. Human infection with the Fasciola parasite, usually considered more of veterinary concern, has recently been recognised as a human health problem. Many countries have implemented health programmes to reduce morbidity and prevalence of schistosomiasis, and control programmes to mitigate food-borne fascioliasis. As these programmes are resource demanding, baseline information on disease prevalence and distribution becomes of great importance. Such information can be made available and put into practice through maps depicting spatial distribution of the intermediate snail hosts. A biology driven model for the freshwater snails Bulinus globosus, Biomphalaria pfeifferi and Lymnaea natalensis was used to make predictions of snail habitat suitability by including potential underlying environmental and climatic drivers. The snail observation data originated from a nationwide survey in Zimbabwe and the prediction model was parameterised with a high resolution Regional Climate Model. Georeferenced prevalence data on urinary and intestinal schistosomiasis and fascioliasis was used to calibrate the snail habitat suitability predictions to produce binary maps of snail presence and absence. Predicted snail habitat suitability across Zimbabwe, as well as the spatial distribution of snails, is reported for three time slices representative for present (1980-1999) and future climate (2046-2065 and 2080-2099). It is shown from the current study that snail habitat suitability is highly variable in Zimbabwe, with distinct high- and low

  17. Echinococcus metacestodes as laboratory models for the screening of drugs against cestodes and trematodes.

    Science.gov (United States)

    Hemphill, A; Stadelmann, B; Scholl, S; Müller, J; Spiliotis, M; Müller, N; Gottstein, B; Siles-Lucas, M

    2010-03-01

    Among the cestodes, Echinococcus granulosus, Echinococcus multilocularis and Taenia solium represent the most dangerous parasites. Their larval stages cause the diseases cystic echinococcosis (CE), alveolar echinococcosis (AE) and cysticercosis, respectively, which exhibit considerable medical and veterinary health concerns with a profound economic impact. Others caused by other cestodes, such as species of the genera Mesocestoides and Hymenolepis, are relatively rare in humans. In this review, we will focus on E. granulosus and E. multilocularis metacestode laboratory models and will review the use of these models in the search for novel drugs that could be employed for chemotherapeutic treatment of echinococcosis. Clearly, improved therapeutic drugs are needed for the treatment of AE and CE, and this can only be achieved through the development of medium-to-high throughput screening approaches. The most recent achievements in the in vitro culture and genetic manipulation of E. multilocularis cells and metacestodes, and the accessability of the E. multilocularis genome and EST sequence information, have rendered the E. multilocularis model uniquely suited for studies on drug-efficacy and drug target identification. This could lead to the development of novel compounds for the use in chemotherapy against echinococcosis, and possibly against diseases caused by other cestodes, and potentially also trematodes.

  18. On the presence and immunoregulatory functions of extracellular microRNAs in the trematode Fasciola hepatica.

    Science.gov (United States)

    Fromm, B; Ovchinnikov, V; Høye, E; Bernal, D; Hackenberg, M; Marcilla, A

    2017-02-01

    Liver flukes represent a paraphyletic group of endoparasitic flatworms that significantly affect man either indirectly due to economic damage on livestock or directly as pathogens. A range of studies have focussed on how these macroscopic organisms can evade the immune system and live inside a hostile environment such as the mammalian liver and bile ducts. Recently, microRNAs, a class of short noncoding gene regulators, have been proposed as likely candidates to play roles in this scenario. MicroRNAs (miRNAs) are key players in development and pathogenicity and are highly conserved between metazoans: identical miRNAs can be found in flatworms and mammalians. Interestingly, miRNAs are enriched in extracellular vesicles (EVs) which are secreted by most cells. EVs constitute an important mode of parasite/host interaction, and recent data illustrate that miRNAs play a vital part. We have demonstrated the presence of miRNAs in the EVs of the trematode species Dicrocoelium dendriticum and Fasciola hepatica (Fhe) and identified potential immune-regulatory miRNAs with targets in the host. After our initial identification of miRNAs expressed by F. hepatica, an assembled genome and additional miRNA data became available. This has enabled us to update the known complement of miRNAs in EVs and speculate on potential immune-regulatory functions that we review here. © 2016 John Wiley & Sons Ltd.

  19. Ultrastructural study of the spermatozoon of the digenean Enodiotrema reductum Looss, 1901 (Platyhelminthes, Plagiorchioidea, Plagiorchiidae), parasite of the green turtle Chelonia mydas (Linnaeus, 1758) in Senegal.

    Science.gov (United States)

    Ndiaye, Papa Ibnou; Quilichini, Yann; Sène, Aminata; Tkach, Vasyl V; Bâ, Cheikh Tidiane; Marchand, Bernard

    2012-08-01

    This study describes the ultrastructural organisation of the spermatozoon of a digenean Enodiotrema reductum (Pligiorchiida: Plagiorchiidae) from the green turtle Chelonia mydas (Linnaeus, 1758). This is the first report of E. reductum from Senegal. The mature spermatozoon of E. reductum is filiform and exhibits two axonemes of the 9 + "1" pattern of the Trepaxonemata, a nucleus, parallel cortical microtubules, an extramembranar ornamentation associated with spine-like bodies and granules of glycogen, among other ultrastructural features. The spermatozoon of E. reductum is distinguished by the presence of a moniliform mitochondrion composed of a bulge associated with a long cord and of a central cytoplasmic expansion. This work represents the first utrastructural study of any representative of the large family Plagiorchiidae. Our results are compared with previously published data on spermatozoa of other digenean taxa.

  20. Pseudosuccinea columella: experimental co-infections of juvenile and pre-adult snails with the digeneans Calicophoron daubneyi and Fasciola hepatica.

    Science.gov (United States)

    Dreyfuss, G; Vignoles, P; Rondelaud, D

    2016-11-01

    Experimental co-infections of juvenile and pre-adult Pseudosuccinea columella with Calicophoron daubneyi and Fasciola hepatica (five miracidia of each digenean per snail) were carried out to determine the aptitude of this lymnaeid to ensure complete larval development of the former parasite, the latter or both. Snails infected with F. hepatica were found in the two groups of juveniles, i.e. 1 and 2 mm at exposure, and the four groups of pre-adults, i.e. 3-6 mm. The highest frequency of F. hepatica, i.e. 37.3%, was noted in the 4 mm group. Low frequencies were noted for C. daubneyi and co-infections of both digeneans in the 3, 4 and 5 mm groups. Two other groups of P. columella, measuring 3 and 4 mm at exposure, were also constituted to study the characteristics of these co-infections. Compared to controls infected only with F. hepatica, the frequency of this digenean infection and the mean number of metacercariae were significantly lower in co-infected snails, while the patent period was significantly shorter. In snails harbouring C. daubneyi only or both digeneans, lower values were noted for prevalence, the patent period and the number of metacercariae. Pre-adult P. columella (3-5 mm in shell height at exposure) were able to sustain larval development of C. daubneyi if they were co-infected with the sequence C. daubneyi +F. hepatica. Low values noted for the prevalence of C. daubneyi infection and the number of metacercariae would be in favour of a still incomplete adaptation between the snail population and the miracidial isolate.

  1. Pathology and first report of natural infections of the eye trematode Philophthalmus lachrymosus Braun, 1902 (Digenea, Philophthalmidae in a non-human mammalian host

    Directory of Open Access Journals (Sweden)

    Roberto Magalhães Pinto

    2005-10-01

    Full Text Available The avian eye trematode Philophthalmus lachrymosus Braun, 1902 is for the first time referred naturally occurring in a non-human mammalian host. Previously, natural infections with P. lachrymosus and other species of Philophthalmus have been occasionally reported from man, with few data on experimental infections of non-human mammals. Results presented here are related to the report of two cases of philophthalmosis due to natural infections of wild Brazilian capybaras, Hydrochaeris hydrochaeris L., 1766 with P. lachrymosus and associated pathology. Clinical signs, gross and microscopic lesions as well as new morphometric data on the parasite are presented.

  2. Fish-borne zoonotic trematode metacercariae in the Republic of Korea.

    Science.gov (United States)

    Sohn, Woon-Mok

    2009-10-01

    The prevalence of fish-borne trematodes (FBT), including Clonorchis sinensis, is still high in riverside areas of the Republic of Korea. The author reviewed the detection and identification methods, differential keys, fish intermediate hosts, and morphological characteristics of FBT metacercariae. FBT metacercariae found in freshwater fish are classified mainly into 4 families, i.e., Opisthorchiidae, Heterophyidae, Echinostomatidae, and Clinostomidae. The metacercariae of C. sinensis, found in 40 species of freshwater fish, are elliptical and 0.15-0.17 x 0.13-0.15 mm in size, have nearly equal sized oral and ventral suckers, brownish pigment granules, and an O-shaped excretory bladder. Their general morphologies are similar to those of Metorchis orientalis (except in the thickness of the cyst wall). Metagonimus spp. (M. yokogawai, M. takahashii, and M. miyatai) metacercariae are subglobular or disc-shaped, and 0.14-0.16 mm in diameter. They have yellow-brownish pigment granules, a ventral sucker deflectively located from median, and a V-shaped excretory bladder. The metacercariae and fish intermediate hosts of Centrocestus armatus, Clinostomum complanatum, and 3 echinostomatid flukes (Echinostoma hortense, E. cinetorchis, and Echinochasmus japonicus) were summarized. FBT metacercariae detected in brackish water fish are mainly members of the Heterophyidae. The morphological characters, identification keys, and fish intermediate hosts of 7 species (Heterophyes nocens, Heterophyopsis continua, Pygidiopsis summa, Stellantchasmus falcatus, Stictodora fuscata, Stictodora lari, and Acanthotrema felis) were also reviewed. The contents treated in this study will provide assistance at the laboratory bench level to those working on recovery of metacercariae from fish hosts and identifying them.

  3. Food-borne trematode infections of humans in the United States of America.

    Science.gov (United States)

    Fried, Bernard; Abruzzi, Amy

    2010-05-01

    This review examines the literature on imported (allochthonous) and local (autochthonous) cases of food-borne trematode (FBT) infections in the United States of America (USA) from 1890 to 2009. Most of the literature is concerned with imported cases of the opisthorchiids Clonorchis sinensis and Opisthorchis viverrini. These flukes cause serious pathology in the liver and biliary system of humans. Chronic cases may induce liver (hepatocarcinoma) and bile duct (cholangiocarcinoma) cancers in humans. Clonorchiasis and opithorchiasis are preventable diseases that can be avoided by eating properly cooked freshwater fish products. Several species of lung flukes in the genus Paragonimus are local or imported FBT in the USA. The endemic cycle occurs in the USA with various local snails and crustaceans serving as intermediate hosts. Paragonimids are acquired when humans eat raw or improperly cooked freshwater crustaceans containing metacercarial cysts. Infection can cause severe lung disease and the symptoms of paragonimiasis often mimic those of tuberculosis and other non-helminthic diseases. Paragonimiasis can be avoided by not eating raw or improperly cooked shellfish. The liver fluke Fasciola hepatica can be acquired by eating raw or uncooked vegetation. The cycle exists in the USA involving local snails and aquatic vegetation. Although some cases are local, most are imported by travelers or immigrants. Fascioliasis can cause serious liver and biliary diseases in humans and consumption of tainted vegetation should be avoided. Lesser known FBT have been reported in the USA including species of Alaria, echinostomids, heterophyids, troglotrematids, and a self-induced infection of Plagiorchis. Treatment of the FBT mentioned in this review consists of various regimens of praziquantel, except for F. hepatica where the drug of choice is triclabendazole.

  4. Increased surfacing behavior in longnose killifish infected by brain-encysting trematode.

    Science.gov (United States)

    Fredensborg, B L; Longoria, A N

    2012-10-01

    Some parasites modify the behavior of intermediate hosts to increase the probability of transmission to the next host in their life cycle. In habitats where this is common, parasites play an important role in predator-prey links and food web dynamics. In this study we used laboratory observations to investigate the behavior of longnose killifish, Fundulus similis, that were naturally infected with metacercariae of the trematode, Euhaplorchis sp. A, from Laguna Madre, south Texas. In particular, we examined whether there was a relationship between the number of metacercariae lodged on the brain of the infected fish and behaviors that made the fish more conspicuous to avian final hosts. We also quantified the abundance and cercariae production of this parasite in its first intermediate snail host, Cerithidea pliculosa , and examined the seasonal variation of Euhaplorchis sp. A in F. similis . Our data demonstrated that Euhaplorchis sp. A affected the surfacing behavior of F. similis in an intensity-dependent manner. Fish with many infections spent longer time at the surface of the water than fish with few infections. Our data also show that Euhaplorchis sp. A is a common parasite in the first intermediate host and produces close to 4,000 cercariae m(-2) day(-1). Consequently 97% of all fish collected and necropsied were infected, with little seasonal variation in the mean abundance of the parasite. Based on our data, Euhaplorchis sp. A is likely important to predator-prey links in Gulf of Mexico estuary food webs, similar to the closely related Euhaplorchis californiensis in southern California. We expect that other closely related species elsewhere may have similar effects on other fish hosts, emphasizing the need for incorporating trophically transmitted parasites in estuarine food web studies.

  5. Parasites of the mink frog (rana septentrionalis) from minnesota, U.S.A.

    Science.gov (United States)

    Schotthoefer, A.M.; Bolek, M.G.; Cole, R.A.; Beasley, V.R.

    2009-01-01

    Twenty-two mink frogs, Rana septentrionalis, collected from two locations in Minnesota, United States, were examined for helminth and protozoan blood parasites in July 1999. A total of 16 parasite taxa were recovered including 5 larval digenean trematodes, 7 adult digenean trematodes, 3 nematodes, and I Trypanosorna species. Infracommunities were dominated by the digeneans in terms of richness and abundance. In particular, echinostomatid metacercariae in the kidneys of frogs were the most common parasites found, infecting 100% of the frogs and consisting of about 90% of all helminth individuals recovered. Gorgodera amplicava, Gorgoderina multilohata, Haernaroloechus pan'iplexus, Haernatoloechus breviplexus, Cosnwcercoides dukae, and Oswaldocruzia pipiens represent new host records. The survey presented here represents the second known helminth survey of mink frogs conducted in North America. A summary of metazoan parasites reported from mink frogs is included.

  6. Molecules and morphology reveal cryptic variation among digeneans infecting sympatric mullets in the Mediterranean.

    Science.gov (United States)

    Blasco-Costa, I; Balbuena, J A; Raga, J A; Kostadinova, A; Olson, P D

    2010-02-01

    We applied a combined molecular and morphological approach to resolve the taxonomic status of Saccocoelium spp. parasitizing sympatric mullets (Mugilidae) in the Mediterranean. Eight morphotypes of Saccocoelium were distinguished by means of multivariate statistical analyses: 2 of Saccocoelium obesum ex Liza spp.; 4 of S. tensum ex Liza spp.; and 2 (S. cephali and Saccocoelium sp.) ex Mugil cephalus. Sequences of the 28S and ITS2 rRNA gene regions were obtained for a total of 21 isolates of these morphotypes. Combining sequence data analysis with a detailed morphological and multivariate morphometric study of the specimens allowed the demonstration of cryptic diversity thus rejecting the hypothesis of a single species of Saccocoelium infecting sympatric mullets in the Mediterranean. Comparative sequence analysis revealed 4 unique genotypes, thus corroborating the distinct species status of Saccocoelium obesum, S. tensum and S. cephali and a new cryptic species ex Liza aurata and L. saliens recognized by its consistent morphological differentiation and genetic divergence. However, in spite of their sharp morphological difference the 2 morphotypes from M. cephalus showed no molecular differentiation and 4 morphotypes of S. tensum were genetically identical. This wide intraspecific morphological variation within S. tensum and S. cephali suggests that delimiting species of Saccocoelium using solely morphological criteria will be misleading.

  7. Transmission and control of Fish-borne Zoonotic Trematodes in aquaculture

    NARCIS (Netherlands)

    Boerlage, A.S.

    2013-01-01

      Fish-borne Zoonotic Trematodes (FZTs) affect the health of millions of humans worldwide. For persistence, the life cycle of FZTs depends on aquatic snails, fish, and definitive hosts like humans, pigs or chickens. Definitive hosts can become infected by eating raw or undercooked fish. Integr

  8. High reinfection rate after preventive chemotherapy for fishborne zoonotic trematodes in Vietnam

    DEFF Research Database (Denmark)

    Lier, Tore; Do, Dung Trung; Johansen, Maria Vang;

    2014-01-01

    sufficient impact alone on the transmission to have a lasting effect on the prevalence. Animal reservoirs and farm management practices must be targeted to achieve sustainable control of fishborne zoonotic trematode infections, hence control programs should consider a One Health approach....

  9. Transmission and control of Fish-borne Zoonotic Trematodes in aquaculture

    NARCIS (Netherlands)

    Boerlage, A.S.

    2013-01-01

      Fish-borne Zoonotic Trematodes (FZTs) affect the health of millions of humans worldwide. For persistence, the life cycle of FZTs depends on aquatic snails, fish, and definitive hosts like humans, pigs or chickens. Definitive hosts can become infected by eating raw or undercooked fish.

  10. Sclerodistomoides pacificus Kamegai, 1971 (Sclerodistomoididae Gibson & Bray, 1979) and Tetrochetus coryphaenae Yamaguti, 1934 (Accacoeliidae Odhner, 1911), two rarely reported digeneans from Tylosurus acus imperialis (Rafinesque) (Belonidae), and a list of helminth parasites of Tylosurus acus (Lacépède).

    Science.gov (United States)

    Châari, Manel; Derbel, Hela; Neifar, Lassâd

    2016-05-01

    Two rarely reported digenean parasites are redescribed: Sclerodistomoides pacificus Kamegai, 1971 (Sclerodistomoididae Gibson & Bray, 1979) from the gall bladder and Tetrochetus coryphaenae Yamaguti, 1934 (Accacoeliidae Odhner, 1911) from the digestive tract of the Mediterranean needlefish Tylosurus acus imperialis (Rafinesque) off Tunisia. Sclerodistomoides pacificus and T. coryphaenae represent new host and geographical records for T. a. imperialis off the Tunisian coast. A complete list of the helminth parasites found in T. a. imperialis and those reported from other subspecies of Tylosurus acus (Lacépède) throughout their wide distributional range is presented. It includes data for T. a. acus (Lacépède), T. a. imperialis, T. a. melanotus (Bleeker) and T. a. rafale Collette & Parin and comprises 46 parasite taxa. Among these, 15 species were recorded from T. a. imperialis off Tunisia.

  11. Calicophoron daubneyi and Fasciola hepatica: characteristics of natural and experimental co-infections of these digeneans in the snail Lymnaea glabra.

    Science.gov (United States)

    Vignoles, P; Titi, A; Mekroud, A; Rondelaud, D; Dreyfuss, G

    2017-01-01

    A retrospective study on different Lymnaea glabra samples collected from central France between 1993 and 2010 was carried out to determine the prevalence of natural co-infections with Calicophoron daubneyi and Fasciola hepatica, and to specify the composition of redial burdens. Experimental infections of L. glabra performed during the same period of time were also analysed to study metacercarial production of each digenean in co-infected snails. Controls were naturally or experimentally co-infected Galba truncatula. In natural co-infections, prevalence was 0.7% in L. glabra (186/25,128) and 0.4% in G. truncatula (137/31,345). Low redial burdens were found in these snails, with F. hepatica rediae significantly more numerous in L. glabra than in G. truncatula (7.5 per snail instead of 5.2). In contrast, the total numbers of C. daubneyi rediae in both lymnaeids were close to each other (4.3 and 3.0 rediae, respectively). In experimentally co-infected groups, prevalence was greater in G. truncatula than in the other lymnaeid (6.3% instead of 3.0%). Significantly shorter patent periods and lower metacercarial production for each digenean were noted in L. glabra than in G. truncatula. However, in both lymnaeids, the two types of cercariae were released during the same shedding waves and several peaks during the patent period were synchronous. In spite of a greater shell height for L. glabra, metacercarial production of both digeneans in co-infected snails was lower than that in G. truncatula, thus indicating a still incomplete adaptation between these French L. glabra and both parasites.

  12. Digenean metacercaria (Trematoda, Digenea, Lepocreadiidae parasitizing "coelenterates" (Cnidaria, Scyphozoa and Ctenophora from Southeastern Brazil

    Directory of Open Access Journals (Sweden)

    André Carrara Morandini

    2005-06-01

    Full Text Available Metacercaria specimens of the genus Opechona (Trematoda: Digenea: Lepocreadiidae are described parasitizing "coelenterates" (scyphomedusae and ctenophores from Southeastern Brazil (São Paulo state. The worms are compared to other Opechona species occurring on the Brazilian coast, but no association has been made because only adult forms of these species have been described. Suppositions as to the possible transference of the parasites are made.Exemplares de metacercárias do gênero Opechona (Trematoda: Digenea: Lepocreadiidae são descritos parasitando "celenterados" (cifomedusas e ctenóforos no sudeste do Brasil (estado de São Paulo. Os vermes foram comparados a outras espécies de Opechona ocorrentes no litoral brasileiro, porém nenhuma associação foi realizada devido às demais espécies terem sido descritas a partir de exemplares adultos. São apresentadas suposições sobre as possíveis formas de transferência dos parasitas.

  13. 河南省马铁菊头蝠肠道寄生吸虫%Rhinolophus ferrumequinum Intestinal Trematodes in Henan Province

    Institute of Scientific and Technical Information of China (English)

    马金友; 余燕; 卜艳珍

    2009-01-01

    2003年8月至2006年12月对河南省7个产地35只马铁菊头蝠肠道检查, 发现吸虫5种, 隶属于3科4属.即:软体肠前腺吸虫、长形肠前腺吸虫、软体亚睾吸虫、朝鲜斜睾吸虫和中孔吸虫未定种.马铁菊头蝠是软体亚睾吸虫的新宿主.软体肠前腺吸虫、长形肠前腺吸虫、软体亚睾吸虫是河南省蝙蝠寄生虫的首次报道.%Five species of trematodes belonging to four genera in three families were obtained through the examination of 35 specimens of horseshoe bats, Rhinolophus ferrumequinum, collected at seven localities in Henan Province, China from August 2003 to December 2006. The following trematodes were recovered in the intestinal tracts of the horseshoe bats: Prosthodendrium chilostomum (Mehlis, 1926) Macy, 1936; Prosthodendrium longiforme (Bhalerao, 1926) Macy, 1936; Postorchigenes duboisi Rohde, 1963; Plagiorchis koreanus Ogata, 1938, and Mesotretes sp. Rhinolophus ferrumequinum is newly recorded as a host bat to P. duboisi. P. chilostomum, P. longiforme and P. duboisi were first recorded in Henan Province.

  14. [Modification of the structure of penial glands in males of the intertidal molluscs Littorina saxatilis and L. obtusata under the influence of the infestation by trematode parthenites].

    Science.gov (United States)

    Ganzha, E V; Granovich, A I

    2008-01-01

    Sporocycts of the "pygmaeus" microphallides (Microphallus piriformes) are localized in hepatopancreas and gonads of Littorina molluscs causing total parasitic castration. A histological study of penial glands in Littorina saxatilis and L. obtusata males infested with trematodes M. piriformes has been made. Copulatory organs of noninfested molluscs, molluscs after recent contamination (with not completely formed daughter sporocysts), and molluscs containing mature metacercariae inside daughter sporocysts were examined. Based on the data obtained, probable dynamics of the histological structure of infested glandular apparatus was established. It was shown, that the trematode infestation have an influence on the muscular and secretory parts of penial glands. The wall of the penial gland muscular capsule becomes more fine in infested L. saxatilis. On the contrary, this wall is vastly thicker in infested L. obtusata, as compared with noninfested individuals. Glandular cells of the molluscs' penial glands decreases the amount of granular secret in both species. In L. obtusata the number of secretory cells is shown to be reduced up to their total disappearance. The above pathological changes probably prevent normal function of penial glands.

  15. Influence of a Trematode Parasite (Microphallus turgidus) on Grass Shrimp ( Palaemonetes pugio ) Response to Refuge and Predator Presence.

    Science.gov (United States)

    Gonzalez, Sara T

    2016-12-01

    The grass shrimp ( Palaemonetes pugio ) is a staple prey species in the diet of many ecologically and economically important species such as blue crab and striped bass and is commonly infected with a trematode parasite, Microphallus turgidus. To complete its life cycle, M. turgidus must be consumed as a metacercaria by a bird or mammal definitive host. Previous research has found that infected grass shrimp behave more conspicuously than uninfected shrimp around predators, which include mummichogs ( Fundulus heteroclitus ). In addition, grass shrimp are more likely to avoid predation when they have access to coarse woody debris (CWD). Aquaria experiments revealed that uninfected shrimp significantly reduce the amount of time spent swimming in the presence of a fish predator, whereas infected shrimp did not exhibit this predation avoidance behavior. Uninfected shrimp also increased predator avoidance behavior ("backthrusts") in the absence of CWD, whereas infected shrimp did not. These findings suggest that M. turgidus does not influence grass shrimp usage of CWD, but it alters shrimp swimming and backthrust behavior, thereby rendering infected shrimp more susceptible to predation. The implications of increased predation by a fish (nonhost or possible paratenic host) versus by a bird or mammal (definitive host) for parasite transmission are discussed.

  16. A Histopathology Study of Caspian Seal (Pusa caspica (Phocidae, Mammalia Liver Infected with Trematode, Pseudamphistomum truncatum (Rudolphi, 1819 (Opisthorchidae, Trematoda.

    Directory of Open Access Journals (Sweden)

    Richard Heckmann

    2014-06-01

    Full Text Available Main objective of this study was to investigate the invasive activity of the liver fluke, Pseudamphistomom truncatum against the Caspian seal (Pusa caspica and was exemplified at the gross, light microscopy (LM and electron microscopy (EM levels.The study was done on a freshly dead Caspian Seal in the southern coast of Caspian Sea. The checked Caspian seal probably being died of canine distemper virus and was found host to numerous parasites of four helminth species.P. truncatum caused edematous foci on the surface of the liver with prominent fluid accumulation. Sections of the liver viewed with LM had multiple necrotic areas with extensive hemorrhaging and disorganized hepatic lobules. Granulocytes and invasion of connective tissue were prominent. Whole worms were visible with invasive pathways through the host tissue. Damage to both hepatic ducts and blood vessels were prominent. At the EM level, organelles within the impacted hepatocytes were disorganized as exemplified by the cristae of the mitochondria and the endoplasmic reticulum. Parasite eggs were scattered throughout the tissue.It was shown that this trematode can be very pathogenic to Caspian Seal and as this only mammal of Caspian Sea is an endangered species; this needs more investigation toward control or possible treatment of this helminth.

  17. Ultrastructural characters of the spermatozoon of the digenean Hypocreadium caputvadum Kacem et al., 2011 (Lepocreadioidea: Lepocreadiidae), an intestinal parasite of Balistes capriscus in Tunisia.

    Science.gov (United States)

    Kacem, Hichem; Bakhoum, Abdoulaye J S; Eira, Catarina; Neifar, Lassad; Miquel, Jordi

    2012-01-01

    The ultrastructural organization of the spermatozoon of the digenean Hypocreadium caputvadum (Lepocreadioidea: Lepocreadiidae) is described. Live digeneans were collected from Balistes capriscus (Teleostei: Balistidae) from the Gulf of Gabès, Tunisia (Eastern Mediterranean Sea). The mature spermatozoon of H. caputvadum shows several ultrastructural characters such as two axonemes of different lengths exhibiting the classical 9+"1" trepaxonematan pattern, a nucleus, two mitochondria, granules of glycogen, external ornamentation of the plasma membrane and two bundles of parallel cortical microtubules. Moreover, in the anterior extremity, the second axoneme is partly surrounded by a discontinuous and submembranous layer of electron-dense material. Our study provides new data on the spermatozoon of H. caputvadum in order to improve the understanding of phylogenetic relationships in the Digenea, particularly in the superfamily Lepocreadioidea. In this context, the electron-dense material surrounding one of the axonemes in the anterior spermatozoon extremity constitutes the unique distinguishing ultrastructural character of lepocreadioideans, and it is present in spermatozoa of lepocreadiids, aephnidiogenids and gyliauchenids.

  18. Determining Intermediate Hosts for Opecoelidae and Microphallidae Species (Platyhelminthes: Trematoda) in the Southeastern Pacific Coast, Using Molecular Markers.

    Science.gov (United States)

    Leiva, Natalia Verónica; López, Zambra; González, María Teresa; Muñoz, Gabriela

    2017-02-01

    Metacercarial stages of digeneans were collected from decapod crustaceans inhabiting intertidal rocky zones in central Chile. The digeneans were identified through a molecular analysis based on the V4 region of the 18S ribosomal RNA gene. We analyzed 356 crustaceans belonging to 10 species, 115 intertidal fish belonging to 6 species, and 4 specimens of 1 coastal bird species. In total, 74.1% of crustaceans were parasitized with metacercariae. We found 1 species of Opecoelidae. This species showed low genetic divergence (0% and 0.1%) with adult digeneans found in intertidal fish and with the species Helicometrina labrisomi infesting a subtidal fish from northern Chile (Labrisomus philippii). Additionally, we found 2 species of Microphallidae, 1 closely related to Maritrema (1.3% genetic distance) and the other related to Microphallus (5% genetic distance). Therefore, our findings showed that the decapod crustaceans are relevant hosts in food webs from the southeastern Pacific coast. Furthermore, we found 5 species of crustaceans as second intermediate hosts for H. labrisomi and 2 species as secondary intermediate hosts for 2 Microphallidae, which contribute to elucidate parts of their life cycles through molecular markers and extended the host distribution of H. labrisomi in the southeastern Pacific coast.

  19. Pathological and parasitological characterization of infection by trematodes (Paramphistomatidae in the large intestine of capybaras

    Directory of Open Access Journals (Sweden)

    Isabela de Oliveira Avelar

    Full Text Available Gross and histological lesions caused by an intestinal parasite were described in three capybaras. The parasites presented a mean length of 14 mm and width of 7 mm, were round to oval or piriform, reddish and pedunculated, and adhered strongly to the mucosa of the large intestine. The intestinal mucosa at the parasite attachment site presented loss of surface epithelium and most glands, with replacement by fibrovascular proliferation that protruded from the mucosa and was involuted by the ventral sucker of the parasite. The lamina propria presented cellular debris, eosinophils, macrophages and plasma cells. The morphological characteristics, observed using serial histological sections, made it possible to classify the parasite as a trematode (Paramphistomatidae, compatible with Taxorchis schistocotyle. One capybara also harbored many ciliated protozoa in the large intestine (at the site of attachment of the parasite and inside the caeca of the trematodes. In conclusion, this study described a multifocal necrotizing colitis associated with T. schistocotyle parasitism in capybaras.

  20. Fish-borne Zoonotic Trematode Metacercariae in the Republic of Korea

    OpenAIRE

    Sohn, Woon-Mok

    2009-01-01

    The prevalence of fish-borne trematodes (FBT), including Clonorchis sinensis, is still high in riverside areas of the Republic of Korea. The author reviewed the detection and identification methods, differential keys, fish intermediate hosts, and morphological characteristics of FBT metacercariae. FBT metacercariae found in freshwater fish are classified mainly into 4 families, i.e., Opisthorchiidae, Heterophyidae, Echinostomatidae, and Clinostomidae. The metacercariae of C. sinensis, found i...

  1. Trematode infections in pregnant ewes can predispose to mastitis during the subsequent lactation period.

    Science.gov (United States)

    Mavrogianni, V S; Papadopoulos, E; Spanos, S A; Mitsoura, A; Ptochos, S; Gougoulis, D A; Barbagianni, M S; Kyriazakis, I; Fthenakis, G C

    2014-02-01

    Objective was to investigate if trematode infections predispose ewes to mastitis and/or metritis. We used 80 trematode-infected ewes: primigravidae in group P-A and multigravidae in M-A remained untreated, primigravidae in P-B and multigravidae in M-B were drenched with netobimin and multigravidae in M-C were given rafoxanide. We collected faecal samples for parasitological examination, blood samples for β-hydroxybutyrate concentration measurement and uterine content, teat duct material and milk samples for bacteriological examination. We found significant differences in blood β-hydroxybutyrate concentrations between M-A, M-B and M-C during pregnancy (P ⩽ 0.002). We did not observe significant differences between groups regarding development of metritis (P>0.83). We found that for M-A, M-B and M-C ewes, respectively, median time to first case of mastitis was 5.75, 21 and 6.75 days after lambing (P = 0.003) and incidence risk of mastitis was 0.308, 0.069 and 0.222 (P = 0.047). We postulate that trematode infections predispose ewes to mastitis; perhaps, increased β-hydroxybutyrate blood concentrations adversely affect mammary cellular defences. This is the first report associating parasitic infections with mastitis in sheep. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. The complete mitochondrial genome of Gastrothylax crumenifer (Gastrothylacidae, Trematoda) and comparative analyses with selected trematodes.

    Science.gov (United States)

    Yang, Xin; Wang, Lixia; Chen, Hongmei; Feng, Hanli; Shen, Bang; Hu, Min; Fang, Rui

    2016-06-01

    In the present study, we sequenced and analyzed the mitochondrial (mt) genome of Gastrothylax crumenifer and compared it with other selected trematodes. The full mt genome of G. crumenifer was amplified, sequenced, assembled, analyzed and then subjected to phylogenetic analysis. The complete mt genome of G. crumenifer is 14,801 bp in length and contains two rRNA genes, two non-coding regions (LNR and SNR), 12 protein-coding genes, and 22 transfer RNA genes. The gene organization of the G. crumenifer mt genome is the same as that of other trematodes, except for Schistosoma haematobium and Schistosoma spindale. All the genes are transcribed in the same direction and rich in "A + T", which is in accordance with other trematodes, such as Fasciola hepatica, Paramphistomum cervi, and Fischoederius elongatus. Phylogenetic analysis using concatenated amino acid sequences of the 12 protein-coding genes showed that G. crumenifer is closely related to F. elongatus. The availability of mt genome sequence of G. crumenifer can provide useful DNA markers for studying the molecular epidemiology and population genetics of this parasite and other paramphistomes.

  3. Comparative allometry growth of some marine fish digenetic trematodes

    Directory of Open Access Journals (Sweden)

    A. Saad-Fares

    1992-01-01

    Full Text Available Allometric growth variation was compared for Plagioporus idoneus, Lepocreadium pegorchis, Opecoeloides furcatus, Bacciger israelensis, Aphanurus stossichi and Parahurleytrema trachinoti collected from East Mediterranean fishes. The pharynx, the oral and the ventral sucker diameters always showed a negative allometry. The other parameters tested were variable with the species. We study the effects of some environmental factors: the influence of the host species is analysed in Plagioporus idoneous, wich parasitizes Oblada melanura, Diplodus sargus and D. vulgaris and in Lepocreadium pegorchis, wich parasitizes Pagellus erythrinus, Lithognathus mormyrus and Spicara smaris; the influence of the microhabitat and the intensity of infection is analysed in Bacciger israelensis and Aphanurus stossichi, both parasites of Boops boops. We report significant differences with the host species, for the allometric growth of the testes; the effect of the microhabitat was revealed by the hindbody allometric value; no significant difference was detected in relation with the intensity of infection.

  4. Seasonal variation of transcriptomic and biochemical parameters of cockles (Cerastoderma edule) related to their infection by trematode parasites.

    Science.gov (United States)

    Magalhães, Luísa; de Montaudouin, Xavier; Freitas, Rosa; Daffe, Guillemine; Figueira, Etelvina; Gonzalez, Patrice

    2017-09-01

    Bivalve populations are controlled by several biotic and abiotic factors. Parasitism is among the biotic factors but is often neglected. In the present study, we focused on the transcriptomic and biochemical responses of Cerastoderma edule when parasitized as first intermediate host by the trematode Bucephalus minimus (sporocyst, the most damaging stage), and taking into account seasonal patterns. In order to test the hypothesis that the presence of B. minimus compromises cockle regular gene expression and biochemical performance and increases their vulnerability to other parasite species infection, cockles were sampled every other month during one year in Arcachon Bay (French Atlantic coast). Overall, results showed that B. minimus induced its first intermediate host defence mechanism against oxidative stress (mainly at gene level), increased host metabolism and energy demand especially in summer (revealed at both gene and biochemical level, although without significant differences) and was accompanied by a higher metacercariae abundance. Results allowed to accept the posted hypothesis and to conclude that transcriptomic and biochemical markers can provide additional and ecologically relevant information about parasite effects on their hosts, reflecting the invasion effects of pathogens but also the environmental conditions that animals experience. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. [The influence of the degree of infestation with trematode parthenites on the structure of penial glands in the mollusks Littorina saxatilis of different age].

    Science.gov (United States)

    Ganzha, E V; Starunova, Z I

    2011-01-01

    Histological and confocal microscopy studies of the structure of penial glands in the Littorina saxatilis males were carried out. The examined mollusks belong to two age groups and were at different stages of spontaneous infection with a trematode from the pygmaeus species group (Microphallus piriformes). Based on comparative analysis of microscopic sections of copulative organs in infested and non-infested mollusks, data on the modifications in histological structure ofpenial glands were obtained. From these data we can suggest that the infestation have an influence on all parts of the gland. Decrease of secret production and reduction of muscular capsule (down to its disappearance) were observed. We suppose that changes in the penial glands structure prevent their normal functioning. In the mollusks infested on reaching the sexual maturity, gradual reduction of distal part of reproductive system was observed, while in the mollusks infested before the sexual maturity, development of ancillary part of reproductive system was blocked.

  6. Hemiuroid trematode sporocysts are undetected by hemocytes of their intermediate host, the ark cockle Anadara trapezia: potential role of surface carbohydrates in successful parasitism.

    Science.gov (United States)

    Kawasaki, Minami; Delamare-Deboutteville, Jerome; Dang, Cecile; Barnes, Andrew C

    2013-12-01

    In order to establish a successful relationship with their hosts, parasites must subvert or evade immune defences. Cockle Anadara trapezia and Sydney Rock oyster (SRO) Saccostrea glomerata live in the same location but only ark cockles are infected by sporocysts of hemiuroid trematode. This provides an opportunity to explore differing interactions between the parasite and the immune system of susceptible and refractive hosts. Rapid migration and encapsulation of sporocysts was observed by SRO hemocytes but not by cockle hemocytes. This migration/encapsulation was inhibited by N-acetylglucosamine or N-acetylgalactosamine but not by the other sugars, implicating specific surface carbohydrates in immune detection. Effector responses of hemocytes were investigated in vitro in terms of production of reactive oxygen production (ROS). Hemocytes of both species strongly reacted to Zymosan, but only SRO hemocytes responded to live sporocysts. Neither species' hemocytes produced ROS in the presence of dead/fixed sporocysts, and there was no suppression of Zymosan-induced respiratory burst by sporocysts. This suggests that immune escape is mediated by avoiding encapsulation, perhaps through molecular mimicry. Membrane-shaving with proteases indicated that sporocyst surface proteins are not a key factors in hemocytic detection. Surface carbohydrates of SRO and cockle hemocytes and of sporocysts were profiled with a panel of biotinylated lectins. This revealed substantial differences between cockle and SRO hemocytes, but greater similarity between cockle hemocytes and sporocysts. Results suggest that surface carbohydrates play an integral role in hemocyte immunorecognition and that surface carbohydrate molecular mimicry is a potential strategy for immune evasion in cockles by hemiuroid trematode sporocysts.

  7. Atrazine reduces the transmission of an amphibian trematode by altering snail and ostracod host-parasite interactions.

    Science.gov (United States)

    Gustafson, Kyle D; Belden, Jason B; Bolek, Matthew G

    2016-04-01

    Trematodes are ubiquitous members of aquatic environments, have many functional roles in ecosystems, and can cause diseases in humans, livestock, and wild animals. Despite their importance and reports of parasite population declines, few studies have concurrently assessed the effects of aquatic contaminants on multiple hosts, multiple parasite life cycle stages, and on transmission-related host-parasite interactions. Here, we test the effects of environmentally relevant concentrations of the herbicide atrazine (0, 3, 30 μg/L) on the establishment and development of an amphibian trematode (Halipegus eccentricus) in a first-intermediate snail host (Physa acuta) and in a second-intermediate ostracod host (Cypridopsis sp.). Additionally, we test the interactive effects of atrazine and parasitism on snail and ostracod survival. Our results indicate that atrazine negatively affects trematode transmission by altering snail and ostracod host-parasite interactions. Although atrazine did not affect the survival of uninfected snails alone, atrazine acted synergistically with parasitism to reduce the longevity of infected snails. As a result, the number of cercariae (i.e., larval trematodes) produced by snails was 50.7 % (3 μg/L) and 14.9 % (30 μg/L) relative to controls. Atrazine exhibited direct negative effects on ostracod survival at 30 μg/L. However, when ostracods were also exposed to trematodes, the negative effects of atrazine on survival were diminished. Although infected ostracod survival remained high, trematode development was significantly reduced, resulting in reduced infectivity of metacercariae (i.e., nongravid adult cysts infective to definite host) to 32.2 % (3 μg/L) and 28.6 % (30 μg/L) relative to the controls. The combination of reduced cercaria production and reduced metacercarial infectivity in the 3 and 30 μg/L atrazine treatment groups reduced the net number of infective worms produced to 16.4 and 4.3 % (respectively) relative to the control

  8. Effects of trematode parasitism on the shell morphology of snails from flow and nonflow environments.

    Science.gov (United States)

    Gustafson, Kyle D; Bolek, Matthew G

    2016-03-01

    The primary function of the gastropod shell is protection. However, shells that function well in one environment may be maladaptive in another. Upon infection, the snail shell protects internal parasites and it is to the parasite's advantage to optimize, or not interfere with, shell functionality. However, parasites, particularly trematodes, are often pathogenic and it is not clear if parasitism will induce environment-dependent or -independent changes to gastropod shells. We conducted a field study and a complementary laboratory experiment to examine the effects of trematode parasitism on shell characteristics (shape, size, and crush resistance) of Physa acuta snails in flow and nonflow environments using geometric morphometrics and crush assays. Field results indicate wetland (nonflow) snails had large, crush resistant shells with narrow apertures and tall spires. In contrast, stream (flow) snails had small, weak shells with wide apertures and short spires. Parasitism had no apparent effect on the crush resistance of wetland snails but significantly reduced the crush resistance of stream snails. Parasitism had no significant effect on overall shell shape in stream or wetland snails. Similar to the results of our field study, nonflow tank snails had significantly more crush resistant shells than flow tank snails. Additionally, the shapes of flow and nonflow tank snails significantly differed where nonflow tank snails resembled wetland snails and flow tank snails resembled stream snails. For laboratory snails, parasitism reduced crush resistance regardless of flow/nonflow treatment. Our results demonstrate that habitat and/or flow treatment was the primary factor affecting P. acuta shell morphology and that trematode parasitism played a secondary role.

  9. Effect of fish size on transmission of fish-borne trematodes (Heterophyidae) to common carps (Cyprinus carpio) and implications for intervention

    NARCIS (Netherlands)

    Boerlage, A.S.; Graat, E.A.M.; Verreth, J.A.J.; Jong, de M.C.M.

    2011-01-01

    Fish-borne trematodes are reported to affect the health of more than 40 million people worldwide. Few experimental studies are available on fish size dependent gain (attack rates of cercariae) or loss (mortality of metacercariae) of fish-borne trematodes. Aim was to quantify the relation between

  10. Distribution of trematodes in snails in ponds at integrated small-scale aquaculture farms.

    Science.gov (United States)

    Boerlage, Annette S; Graat, Elisabeth A M; Verreth, Johan A; de Jong, Mart C M

    2013-03-01

    In integrated small-scale aquaculture farming, animal and human excreta maybe used as fish feed and pond fertilizer, thereby enhancing transmission of fish-borne zoonotic trematodes (FZTs) from final hosts, like humans, pigs and chickens, to snails. Areas within a pond could vary in trematode egg-load due to the immediate bordering land, and this might provide implications for control of these trematodes or sampling in field studies measuring FZT prevalence in snails. We therefore estimated the effect of bordering land use on prevalence and FZT burden in snails in different areas within small-scale aquaculture ponds. Nine sampling areas within a pond were assigned in six ponds. For each sampling area, about 120 Melanoides tuberculata snails were collected. Based on land use bordering a sampling area, these were categorized in 5 risk-categories: low-risk (road, rice planted in pond, agriculture, or middle of pond), human access point to pond, livestock sty (pigs or poultry), both human access point and livestock sty, and water connection to canal. In total, 5392 snails were collected. Percentages of snails with parapleurolophocercous cercariae varied between 6% in areas categorized as low-risk and areas with livestock sty only to 15% in areas with both human access point and livestock sty; only this 15% was significantly different from the prevalence in the low-risk category. Percentages of snails with xiphidio cercariae did not differ between risk-categories and varied between 5% and 10%. Mean snail size was 15.2mm, and was significantly associated with both the probability of infection as well as parasite burden. Very small differences in parasite burden were found at different land use areas; the maximum difference was about 11 cercariae. This study demonstrated only small differences between areas surrounding a pond on risk of snails to be infected with fish-borne trematodes within different pond areas. In field studies on FZTs in M. tuberculata snails in ponds

  11. Relationship between snail population density and infection status of snails and fish with zoonotic trematodes in Vietnamese carp nurseries

    DEFF Research Database (Denmark)

    Clausen, Jesper Hedegaard; Madsen, Henry; Murrell, Kenneth Darwin

    2012-01-01

    Fish-borne zoonotic trematodes (FZT) are a food safety and health concern in Vietnam. Humans and other final hosts acquire these parasites from eating raw or under-cooked fish with FZT metacercariae. Fish raised in ponds are exposed to cercariae shed by snail hosts that are common in fish farm...... ponds. Previous risk assessment on FZT transmission in the Red River Delta of Vietnam identified carp nursery ponds as major sites of transmission. In this study, we analyzed the association between snail population density and heterophyid trematode infection in snails with the rate of FZT transmission...

  12. The life cycle of Prosorhynchoides carvajali (Trematoda: Bucephalidae) involving species of bivalve and fish hosts in the intertidal zone of central Chile.

    Science.gov (United States)

    Muñoz, G; Valdivia, I; López, Z

    2015-09-01

    We describe the life cycle of the bucephalid Prosorhynchoides carvajali from the intertidal rocky zone of central Chile. To elucidate the life cycle of this digenean, two mytilid bivalves, Semimytilus algosus and Perumytilus purpuratus, and ten intertidal fish species belonging to the families Blenniidae, Tripterygiidae, Labrisomidae, Kyphosidae and Gobiesocidae were analysed for natural infections. In addition, experimental infections of fish were undertaken and molecular analyses were performed of several developmental stages of the digeneans in various host species. Experimental infections of fish were made from infected mytilids to determine which fish species were suitable for the metacercarial stage of Prosorhynchoides. We also determined the abundance and prevalence of metacercariae in natural infections in fish and found that they were lower than in the experimental infections. A molecular analysis showed that sporocysts from S. algosus were identical to metacercariae from five fish species and P. carvajali adults. Sporocysts isolated from P. purpuratus were similar to metacercaria found in one fish species only (G. laevifrons) but were different from P. carvajali, with 1.9-2.0% genetic divergence. Therefore, the complete life cycle of P. carvajali consists of the mytilid species S. algosus as the first intermediate host, at least five intertidal fish species as second intermediate hosts (Scartichthys viridis, Auchenionchus microcirrhis, Hypsoblennius sordidus, Helcogrammoides chilensis and Gobiesox marmoratus), two carnivorous fish as definitive hosts (Auchenionchus microcirrhis and A. variolosus) and one occasional definitive host (Syciases sanguineus). This is the second description of a life cycle of a marine digenean from Chile.

  13. Combined Effects of Pesticides and Trematode Infections on Hourglass Tree Frog Polypedates cruciger.

    Science.gov (United States)

    Jayawardena, Uthpala A; Rohr, Jason R; Navaratne, Ayanthi N; Amerasinghe, Priyanie H; Rajakaruna, Rupika S

    2016-03-01

    The impact of widespread and common environmental factors, such as chemical contaminants, on infectious disease risk in amphibians is particularly important because both chemical contaminants and infectious disease have been implicated in worldwide amphibian declines. Here we report on the lone and combined effects of exposure to parasitic cercariae (larval stage) of the digenetic trematode, Acanthostomum burminis, and four commonly used pesticides (insecticides: chlorpyrifos, dimethoate; herbicides: glyphosate, propanil) at ecologically relevant concentrations on the survival, growth, and development of the common hourglass tree frog, Polypedates cruciger Blyth 1852. There was no evidence of any pesticide-induced mortality on cercariae because all the cercariae successfully penetrated each tadpole host regardless of pesticide treatment. In isolation, both cercarial and pesticide exposure significantly decreased frog survival, development, and growth, and increased developmental malformations, such as scoliosis, kyphosis, and also edema and skin ulcers. The combination of cercariae and pesticides generally posed greater risk to frogs than either factor alone by decreasing survival or growth or increasing time to metamorphosis or malformations. The exception was that lone exposure to chlorpyrifos had higher mortality without than with cercariae. Consistent with mathematical models that suggest that stress should increase the impact of generalist parasites, the weight of the evidence from the field and laboratory suggests that ecologically relevant concentrations of agrochemicals generally increase the threat that trematodes pose to amphibians, highlighting the importance of elucidating interactions between anthropogenic activities and infectious disease in taxa of conservation concern.

  14. A portrait of the transcriptome of the neglected trematode, Fasciola gigantica--biological and biotechnological implications.

    Directory of Open Access Journals (Sweden)

    Neil D Young

    Full Text Available Fasciola gigantica (Digenea is an important foodborne trematode that causes liver fluke disease (fascioliasis in mammals, including ungulates and humans, mainly in tropical climatic zones of the world. Despite its socioeconomic impact, almost nothing is known about the molecular biology of this parasite, its interplay with its hosts, and the pathogenesis of fascioliasis. Modern genomic technologies now provide unique opportunities to rapidly tackle these exciting areas. The present study reports the first transcriptome representing the adult stage of F. gigantica (of bovid origin, defined using a massively parallel sequencing-coupled bioinformatic approach. From >20 million raw sequence reads, >30,000 contiguous sequences were assembled, of which most were novel. Relative levels of transcription were determined for individual molecules, which were also characterized (at the inferred amino acid level based on homology, gene ontology, and/or pathway mapping. Comparisons of the transcriptome of F. gigantica with those of other trematodes, including F. hepatica, revealed similarities in transcription for molecules inferred to have key roles in parasite-host interactions. Overall, the present dataset should provide a solid foundation for future fundamental genomic, proteomic, and metabolomic explorations of F. gigantica, as well as a basis for applied outcomes such as the development of novel methods of intervention against this neglected parasite.

  15. Rediae of echinostomatid and heterophyid trematodes suppress phagocytosis of haemocytes in Littorina littorea (Gastropoda: Prosobranchia).

    Science.gov (United States)

    Iakovleva, Nadya V; Shaposhnikova, Tania G; Gorbushin, Alexander M

    2006-05-01

    A modulation of the phagocytic activity of hemocytes from the common periwinkle Littorina littorea by secretory-excretory products (SEP) released by trematode rediae during axenic in vitro cultivation was studied. The SEP released by the parasites Himasthla elongata (Echinostomatidae) and Cryptocotyle lingua (Heterophyidae) were found to inhibit the phagocytosis of zymozan particles by periwinkle hemocytes. The specificity of SEP effects was assessed: SEP of Himasthla militaris and Cryptocotyle concavum, two trematodes belonging to the same genera but infecting another closely related prosobranch snail Hydrobia ulvae, were also shown to be able to suppress L. littorea hemocytes phagocytic activity. However, no decrease in phagocytosis rate was observed when SEP of H. elongata and C. lingua were applied to monolayers of hemocytes from the bivalve mollusc Mytilus edulis. SEP from H. elongata was fractionated; only those fractions containing proteins of molecular weight more than 50 kDa were shown to possess inhibitory activity. Different H. elongata SEP concentrations were tested in for their ability to suppress phagocytosis by L. littorea hemocytes. Even very low SEP concentrations were shown to retain their ability to decrease phagocytosis rate, the inhibitory effect being dose-dependent. Hemocytes derived from snails naturally infected with H. elongata were also found to have lower phagocytic ability as compared to healthy individuals.

  16. [The influence of the trematode invasion on the average daily rations and electoral nourishment of Planorbarius corneus (Mollusca: Pulmonata: Bulinidae)].

    Science.gov (United States)

    Stadnichenko, A P; Girin, V K

    2005-01-01

    The influence of the Trematode invasion on the average daily rations and electoral nourishment of the two size groups in the great ramshorn snail Planorbarius corneus, "young" (12-24 mm in diameter) and "old" (24-36.5 mm in diameter), have been investigated.

  17. Higher attack rate of fish-borne trematodes (Heterophyidae) in common carp fingerlings (Cyprinus carpio) at lower fish weight

    NARCIS (Netherlands)

    Boerlage, A.S.; Graat, E.A.M.; Verreth, J.A.J.; Jong, de M.C.M.

    2012-01-01

    Fish-borne zoonotic trematodes (FZTs) can cause pathology in humans. Fish weight was reported as important risk factor for transmission from snail to fish. However, in fingerlings, the relation between fish weight and infection is unknown. Aim was quantifying the effect of fish weight on infection

  18. Effect of dose and frequency of exposure to infectious stages on trematode infection intensity and success in mussels

    NARCIS (Netherlands)

    Liddell, C.; Welsh, J.E.; van der Meer, J.; Thieltges, D.W.

    2017-01-01

    Marine parasites such as trematodes often compromise the fitness of their hosts. Sucheffects are generally considered to be density-dependent, i.e. the greater the infection intensity inthe host, the greater the detrimental impact on host fitness. However, the mechanisms determininginfection in

  19. [Trematode distribution in Littorina saxatilis populations can support the reproductive potential of the host: "toilers" and "idlers" among female periwinkles].

    Science.gov (United States)

    Granovich, A I; Iagunova, E B; Sokolova, I M

    2012-01-01

    Co-evolution between parasites and their hosts can involve adaptations on the individual and population levels likely to be especially prominent in the systems where parasites have a direct strong impact on the hosts fitness, as is the case with castrating trematodes and their gastropod hosts. We studied populations of the rough periwinkles Littorina saxatilis in the White Sea infested by castrating trematodes to determine whether spatial and temporal variations in the trematode prevalence affect the demographic structure of the host population. Sex, age, reproductive status and infestation of L. saxatilis from 19 populations with different trematode burdens (from < 1 % to 30-50%); in two of these 19 populations (RI and KLN) a long-term monitoring over the period of 15-20 years was also performed. These analyses showed that (1) the average age of gravid females did not correlate with the trematode prevalence of the population, (2) the ratio was skewed towards females, (3) the trematode prevalence in females tended to be higher than in males, (4) the proportion of the non-infested gravid females of the younger ages classes (2-4 years) did not correlate with trematode prevalence of the population. The proportion of young non-infested females that were not reproducing ("idlers") decreased significantly with increasing infestation prevalence when compared among different populations of L. saxatilis, but remained relatively stable within two heavily infested populations RI and KLN despite the year-to-year fluctuations of the infestation prevalence. Thus, a demographic mechanism to compensate for the parasite pressure in L. saxatilis populations may involve the maintenance of a relatively constant proportion of uninfected gravid female ("toilers") at the expense of uninfected, but not reproducing females of fertile age ("idlers"); the latter can be viewed a reproductive reserve of the population tapped into under the conditions of high infestation prevalence. This

  20. Local adaptation of the trematode Fasciola hepatica to the snail Galba truncatula

    Directory of Open Access Journals (Sweden)

    Dreyfuss G.

    2012-08-01

    Full Text Available Experimental infections of six riverbank populations of Galba truncatula with Fasciola hepatica were carried out to determine if the poor susceptibility of these populations to this digenean might be due to the scarcity or the absence of natural encounters between these snails and the parasite. The first three populations originated from banks frequented by cattle in the past (riverbank group whereas the three others were living on islet banks without any known contact with local ruminants (islet group. After their exposure, all snails were placed in their natural habitats from the end of October up to their collection at the beginning of April. Compared to the riverbank group, snails, which died without cercarial shedding clearly predominated in the islet group, while the other infected snails were few in number. Most of these last snails released their cercariae during a single shedding wave. In islet snails dissected after their death, the redial and cercarial burdens were significantly lower than those noted in riverbank G. truncatula. Snails living on these islet banks are thus able to sustain larval development of F. hepatica. The modifications noted in the characteristics of snail infection suggest the existence of an incomplete adaptation between these G. truncatula and the parasite, probably due to the absence of natural contact between host and parasite.

  1. The metacercariae of sibling species of Meiogymnophallus, including M. rebecqui comb. nov. (Digenea: Gymnophallidae), and their effects on closely related Cerastoderma host species (Mollusca: bivalvia).

    Science.gov (United States)

    Bowers, E A; Bartoli, P; Russell-Pinto, F; James, B L

    1996-01-01

    The morphology and ecology are described for four sibling species of digenean metacercariae: Meiogymnophallus minutus (Cobbold 1859), M. strigatus (Lebour 1908) from the estuarine cockle Cerastoderma edule L. and M. fossarum (Bartoli, 1965) and M. rebecqui (Bartoli, 1983) comb. nov. from the brackish water lagoon cockle C. glaucum (Poiret). Although occupying different sites within the two species of cockle, both M. minutus and M. fossarum infections result in pathological effects that may cause heavy host mortality. Remarkably, they also result in an inversion of the cockles in situ in the sand such that predation by the final host species is enhanced.

  2. Emergence of the Zoonotic Biliary Trematode Pseudamphistomum truncatum in Grey Seals (Halichoerus grypus) in the Baltic Sea

    Science.gov (United States)

    Bergman, Anders; Bignert, Anders; Höglund, Johan; Lundström, Karl; Strömberg, Annika; Bäcklin, Britt-Marie

    2016-01-01

    The biliary trematode Pseudamphistomum truncatum parasitizes a wide range of fish-eating mammals, including humans. Here we report the emergence of this parasite in grey seals (Halichoerus grypus) in the Baltic Sea. One hundred eighty-three of 1 554 grey seals (11.9%) examined from 2002–2013 had detectable hepatobiliary trematode infection. Parasite identification was confirmed as P. truncatum by sequencing the ITS2 region of a pool of five to 10 trematodes from each of ten seals collected off the coast of seven different Swedish counties. The proportion of seals parasitized by P. truncatum increased significantly over time and with increasing age of seals. Males were 3.1 times more likely to be parasitized than females and animals killed in fishery interactions were less likely to be parasitized than animals found dead or hunted. There was no significant difference in parasitism of seals examined from the Gulf of Bothnia versus those examined from the Baltic Proper. Although the majority of infections were mild, P. truncatum can cause severe hepatobiliary disease and resulted in liver failure in at least one seal. Because cyprinid fish are the second intermediate host for opisthorchiid trematodes, diets of grey seals from the Baltic Sea were analysed regarding presence of cyprinids. The proportion of gastrointestinal tracts containing cyprinid remains was ten times higher in seals examined from 2008 to 2013 (12.2%) than those examined from 2002 to 2007 (1.2%) and coincided with a general increase of trematode parasitism in the host population. The emergence and relatively common occurrence of P. truncatum in grey seals signals the presence of this parasite in the Baltic Sea ecosystem and demonstrates how aquatic mammals can serve as excellent sentinels of marine ecosystem change. Investigation of drivers behind P. truncatum emergence and infection risk for other mammals, including humans, is highly warranted. PMID:27755567

  3. Population dynamics of the minute intestinal trematode Haplorchis pumilio following experimental infection of young dogs

    DEFF Research Database (Denmark)

    Nissen, Sofie; Nguyen, Lan Anh; Thamsborg, Stig Milan;

    2011-01-01

    Fishborne zoonotic trematodes (FZT) are highly prevalent in Southeast Asia. Recent studies on domestic animal’s role in the transmission of FZT in Northern Vietnam found that the most prevalent FZT was Haplorchis pumilio. The importance of dogs, cats and pigs was assessed, and dogs were found...... to have the highest intensity of infection and contribute the most to the contamination of the environment with FZT eggs in the Nam Dinh province - a highly endemic area for FZTs. Given the free roaming and fish-eating behaviour of many dogs in rural Vietnam controlling the infection in dogs represents......-reared dogs (3-6 months old), were each orally infected with 500 metacercariae (mainly H. pumilio) obtained by artificially digestion of naturally infected fish. Another eight dogs were included as uninfected controls. Faecal examination for eggs was performed twice weekly using a sieving and sedimentation...

  4. Experimental infection with the small intestinal trematode, Haplorchis pumilio, in young dogs

    DEFF Research Database (Denmark)

    Nissen, Sofie; Nguyen, Lan Anh Thi; Dalsgaard, Anders

    2013-01-01

    Fishborne zoonotic trematodes (FZT) are highly prevalent in Southeast Asia. Recent studies on the role of domestic animals in the transmission of FZT in Northern Vietnam found that dogs, mainly infected with Haplorchis pumilio, contributed widely to the transmission of FZT. On this background, we...... conducted an experimental infection with H. pumilio to elucidate population dynamics and host reactions in dogs. Eight household-reared dogs (3-6 months old), were each orally infected with 500 H. pumilio metacercariae obtained by artificial digestion of naturally infected fish. Another eight dogs were...... included as uninfected controls. Faecal examination for eggs was performed twice weekly using a sieving and sedimentation technique. Body temperature and weight of the dogs were measured as was total white blood cells, blood eosinophils and packed cell volume. Subsets of dogs were examined post...

  5. Raw-fish-eating behavior and fishborne zoonotic trematode infection in people of northern Vietnam

    DEFF Research Database (Denmark)

    Phan, Van Thi; Ersbæll, Annette Kjær; Do, Dung Trung

    2011-01-01

    eating raw fish in restaurants had 3.6 times higher odds of FZT infection (p = 0.009) than people eating raw fish at home. A successful program to control FZT must be based on in-depth knowledge on the social and anthropological determinants of people's raw-fish-eating behavior and hygiene practices...... fishborne zoonotic trematode (FZT) infection. The present study was done in a fish-farming community in Nam Dinh, Vietnam, to obtain information about habits of eating raw fish dishes and risks for human FZT infection. Discussions were held in different groups divided by gender and age on raw......-fish-eating behavior. A total of 180 household members were interviewed and their stool samples analyzed to identify risk factors of FZT infection. There was awareness about the risk of liver fluke infections from eating raw fish. However, many older people accepted these risks and continued eating raw fish...

  6. New data in France on the trematode Alaria alata (Goeze, 1792) obtained during Trichinella inspections

    Science.gov (United States)

    Portier, J.; Jouet, D.; Ferté, H.; Gibout, O.; Heckmann, A.; Boireau, P.; Vallée, I.

    2011-01-01

    The trematode Alaria alata is a cosmopolite parasite found in red foxes (Vulpes vulpes), the main definitive host in Europe. In contrast only few data are reported in wild boars (Sus scrofa), a paratenic host. The aim of this paper is to describe the importance and distribution of Alaria alata mesocercariae in wild boars, information is given by findings of these larvae during Trichinella mandatory meat inspection on wild boars’ carcasses aimed for human consumption. More than a hundred cases of mesocercariae positive animals are found every year in the East of France. First investigations on the parasite’s resistance to deep-freezing in meat are presented in this work. PMID:21894269

  7. Freshwater aquaculture nurseries and infection of fish with zoonotic trematodes, Vietnam.

    Science.gov (United States)

    Phan, Van Thi; Ersbøll, Annette Kjær; Nguyen, Thanh Thi; Nguyen, Khue Viet; Nguyen, Ha Thi; Murrell, Darwin; Dalsgaard, Anders

    2010-12-01

    Residents of the Red River Delta region of northern Vietnam have a long tradition of eating raw fish. Fish-borne zoonotic trematodes (FZTs) are estimated to infect ≈1 million persons in Vietnam. It remains uncertain at what stages in the aquaculture production cycle fish become infected with FZTs. Newly hatched fish (fry) from 8 hatcheries and juveniles from 27 nurseries were therefore examined for FZT infection. No FZTs were found in fry from hatcheries. In nurseries, FZT prevalence in juveniles was 14.1%, 48.6%, and 57.8% after 1 week, 4 weeks, and when overwintered in ponds, respectively. FZT prevalence was higher in grass carp (paquaculture management practices, particularly in nurseries, to minimize the risk of distributing infected juveniles to grow-out ponds and, subsequently, to markets for human consumption.

  8. Immune response to sympatric and allopatric parasites in a snail-trematode interaction

    Directory of Open Access Journals (Sweden)

    Osnas Erik E

    2005-05-01

    Full Text Available Abstract Background The outcome of parasite exposure depends on the (1 genetic specificity of the interaction, (2 induction of host defenses, and (3 parasite counter defenses. We studied both the genetic specificity for infection and the specificity for the host-defense response in a snail-trematode interaction (Potamopyrgus antipodarum-Microphallus sp. by conducting a reciprocal cross-infection experiment between two populations of host and parasite. Results We found that infection was greater in sympatric host-parasite combinations. We also found that the host-defense response (hemocyte concentration was induced by parasite exposure, but the response did not increase with increased parasite dose nor did it depend on parasite source, host source, or host-parasite combination. Conclusion The results are consistent with a genetically specific host-parasite interaction, but inconsistent with a general arms-race type interaction where allocation to defense is the main determinant of host resistance.

  9. A cross-sectional study on the potential transmission of the carcinogenic liver fluke Opisthorchis viverrini and other fishborne zoonotic trematodes by aquaculture fish.

    Science.gov (United States)

    Pitaksakulrat, Opal; Sithithaworn, Paiboon; Laoprom, Nonglak; Laha, Thewarach; Petney, Trevor N; Andrews, Ross H

    2013-01-01

    Throughout Southeast Asia and China, eating raw and or partially cooked cyprinid fish causes liver (hepatobiliary) disease and cancer (cholangiocarcinoma) due to fishborne zoonotic trematodes (FZT), in particular Clonorchis sinensis and Opisthorchis viverrini. The primary source of transmission is by native fish, but aquaculture fish are also reported to have high infective potential. Here, a cross-sectional survey of FZT in fish farms was conducted in an endemic area in Khon Kaen Province, Thailand. By using conventional and polymerase chain reaction (PCR) methods, we detected O. viverrini and FZT metacercariae (Centrocestus formosanus and Haplorchis taichui) in two popular fish species, Barbonymus gonionotus (silver barb) and Cirrhinus mrigala (mrigal), from aquaculture farms. Both species were infected in five of six farms examined by PCR but not by conventional methods, yet the prevalence of FZT metacercariae in aquaculture fish was high (46.9%). In addition to O. viverrini (17.1%), the native fish Cyclocheilichthys armatus and Hampala dispar had a prevalence of FZT of 81.4%, which included 5.7% for C. formosanus and 17.1% for H. taichui by conventional method. To our knowledge, this is the first discovery of O. viverrini in aquaculture fish in Thailand. More comprehensive studies are required to determine if human-induced disease transmission coupled with natural transmission cycle occurs throughout the aquaculture industry in the region. This has significant impact on food quality and safety, and provides the basis for the development of an effective strategy for the prevention and control of foodborne diseases.

  10. Chromosome morphometry in opisthorchiid species (Platyhelminthes, Trematoda).

    Science.gov (United States)

    Zadesenets, Kira S; Polyakov, Andrey V; Katokhin, Alexey V; Mordvinov, Viatcheslav A; Rubtsov, Nikolay B

    2017-08-01

    Few existing studies have dealt with cytogenetics in trematodes, largely due to the attendant technical difficulty of chromosome preparation. We performed a comparative analysis of chromosomes in five opistorchiid species, including Opisthorchis felineus Rivolta, 1884, Opisthorchis viverrini Poirier, 1886, Clonorchis sinensis Cobbold, 1875, Metorchis xanthosomus Creplin 1846, and Metorchis bilis (Braun, 1790) Odening, 1962. For some of these species, no detailed morphometric description of their karyotypes has yet been published; for the karyotype of Metorchis bilis this is the first-ever description. We found that opisthorchiids, like other trematodes, are characterized by karyotypic conservatism (N=6-7) and karyotype asymmetry, although comparison of chromosome morphometric traits did reveal differences between the karyotypes of the species. Moreover, to address certain a methodological issue in trematode chromosome preparation, we analyzed how the source of chromosomal material (partenitae or mature flukes) and the chromosome preparation techniques used (air-drying and cell suspension methods) affected chromosome spreading and size, concluding that the most reliable comparative method involves comparing relative parameters (relative length, arm ratio, centromeric index) of chromosomes prepared using the same technique. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  11. 澜沧江下游区域食源性吸虫中间宿主囊蚴感染情况调查%Foodborne trematode metacercariae in intermediate hosts in the lower Lancang River basin

    Institute of Scientific and Technical Information of China (English)

    姜进勇; 杜尊伟; 汪丽波; 王学忠; 吴方伟

    2013-01-01

    目的 了解澜沧江下游区域食源性吸虫中间宿主携带囊蚴情况,为云南省食源性吸虫病的防治提供依据.方法 采集的鱼类、溪蟹和青蛙等标本采用人工消化法和水洗沉淀法进行检查. 结果 食源性吸虫中间宿主感染有钩棘单睾吸虫、多刺棘带吸虫、台湾次睾吸虫等囊蚴,集贸市场中南鳢和青蛙的吸虫囊蚴感染率分别为26.56%和3.81%.景洪市勐养镇、勐罕镇、嘎洒镇河流中捕获的南鳢吸虫囊蚴感染率分别为31.60%、77.50%和14.00%. 结论 澜沧江下游某些鱼种、青蛙和溪蟹是食源性吸虫的中间宿主,各级卫生机构应加大食源性吸虫病的健康教育,提高人群防病意识,减少食源性吸虫病.%A survey was conducted to investigate the prevalence of food-borne trematode metacercariae in intermediate hosts in the lower Lancang River basin from Aug. 2009 to July 2010. The survey was done to provide evidence for food-borne trematode prevention and control. Samples of fish, frogs, and crabs were examined by artificial digestion or precipitation and washing. Three species of metacercariae. Haplorchis pumilio, Centrocestus formosanus, and Metorchis orien-talis Tanabc, were mainly detected from the samples. Dwarf snakehead and frogs collected from markets were infected with metacercariae al a respective rate of 26. 56% and 3. 81%. Dwarf snakehead in the town of Mengyang were infected with metacercariae at a rate of 31. 6% , those in the town of Menghan were infected at a rate of 77. 5% , and those in the town of Gasa were infected at a rate of 14. 0%. Results confirmed that some species of freshwater fish and crab play a role as second intermediate hosts of foodborne trematode metacercariae in the lower Lancang River basin. All levels of health facilities should increase health education regarding food-borne trematodes, increase public awareness of disease prevention, and reduce the prevalence of food-borne trematodes.

  12. Patterns of trematode infections of Opisthorchis viverrini (Opisthorchiidae) and Haplorchis taichui (Heterophyidae) in human populations from two villages in Savannakhet Province, Lao PDR.

    Science.gov (United States)

    Sato, M; Pongvongsa, T; Sanguankiat, S; Yoonuan, T; Kobayashi, J; Boupha, B; Nishimoto, F; Moji, K; Sato, M O; Waikagul, J

    2015-07-01

    The liver fluke, Opisthorchis viverrini, and the minute intestinal fluke, Haplorchis taichui, are prevalent in many Asian countries. This study analysed the patterns of infections of O. viverrini and H. taichui in Lahanam and Thakhamlien villages (Savannakhet Province, Lao PDR), in two cross-sectional investigations. Out of a total of 207 human participants, post-anthelmintic treatment positivity rates for expelled worms were 170 (82.1%) for H. taichui and 65 (31.4%) for O. viverrini. Both these species co-exist in the study villages. When each parasite was analysed separately, H. taichui infections reached a plateau among people aged >20 years. Opisthorchis viverrini infection rates were highest in the age group 21-30 years, with decreasing infection rates after the age of 30. Our findings indicated that fish-borne trematode infections were more prevalent among adults. Fish, common intermediate hosts, were acquired in the study area for analysis. The examination of 35 species of fish as intermediate hosts found O. viverrini metacercariae in only six species, and these were found mostly during the month of November. Many farmers who live on the rice fields obtain their food from their immediate environment, including these intermediate-host fish, potentially putting them at greater risk of O. viverrini infection. By contrast, H. taichui metacercariae were found in three species of fish obtained from the market, meaning that anyone could consume them and become infected. If people who work in rice fields limit the species of fish they consume, or avoid consuming raw fish during the month of November, they may reduce their risk of O. viverrini infection.

  13. Associations between trematode infections in cattle and freshwater snails in highland and lowland areas of Iringa Rural District, Tanzania.

    Science.gov (United States)

    Nzalawahe, Jahashi; Kassuku, Ayub A; Stothard, J Russell; Coles, Gerald C; Eisler, Mark C

    2015-09-01

    The epidemiology of trematode infections in cattle was investigated within highland and lowland areas of Iringa Rural District, in southern Tanzania. Fecal samples were collected from 450 cattle in 15 villages at altitudes ranging from 696 to 1800 m above the sea level. Freshwater snails were collected from selected water bodies and screened for emergence of cercariae. The infection rates in cattle were Fasciola gigantica 28·2%, paramphistomes 62·8% and Schistosoma bovis 4·8%. Notably, prevalence of trematode infections in cattle was much higher in highland (altitude > 1500 m) as compared with lowland (altitude snails collected included Lymnaea natalensis, Bulinus africanus, Bulinus tropicus, Bulinus forskali, Biomphalaria pfeifferi, Melanoides tuberculata and Bellamya constricta with a greater proportion of highland (75%) than lowland (36%) water bodies harbouring snails. Altitude is a major factor shaping the epidemiology of F. gigantica and paramphistomes infections in cattle in Iringa Rural District with greater emphasis upon control needed in highland areas.

  14. [Effect of bolus administration of albendazole into the rumen on gastrointestinal nematodes and the Dicrocoelium dendriticum trematode in sheep].

    Science.gov (United States)

    Corba, J; Krupicer, I; Várady, M; Pet'ko, B

    1994-01-01

    The efficacy of intraruminal albendazole (ABZ) capsules (Proftril-Captec) and the effect of treatment on productivity parameters were studied in two experiments totally on 466 ewes naturally infected with gastrointestinal nematodes and trematodes D. dendriticum. Ovoscopical tests revealed that treated animals remained negative during 10-12 weeks after the administration of capsules and that pasture contamination with helminths was significantly reduced. Necropsy revealed 96.9-99.2% efficacy against nematodes Nematodirus spp., Oesophagostomum spp., Cooperia spp., Trichostrongylus spp. and Trichuris ovis. Priority finding is the efficacy of ABZ capsules against trematodes D. dendriticum which was in the first experiment 88.5% and in the second experiment 91.8%. During the 6-month pasture season treated ewes produced on average 2.56 kg cheese and 0.6 kg wool per ewe more than untreated controls.

  15. 吸虫线粒体基因研究进展%Research progress on trematode mitochodrial genome

    Institute of Scientific and Technical Information of China (English)

    王曼; 王光西; 张锡林

    2011-01-01

    Trematode belongs to Platyhelminthes' s trematoda,it' s an important class of parasitic zoonosis,not only seriously threatening human health,but also affecting the production of aquaculture and livestock industry.The study on mitochondrial genome is one of the most essential part in molecular biology.This article focused on the composition of trematode mitochondrial genome,structure and significance of mitochondrial DNA research and the applications of the trematode mitochondrial DNA research.%吸虫属于扁形动物门吸虫纲,是一类重要的人兽共患蠕虫病病原,对人体危害很大,也严重影响水产业和畜牧业的发展.分子生物学方法是研究吸虫的重要工具.该文对吸虫线粒体分子生物学的研究进行总结,重点介绍吸虫线粒体基因的组成和结构特点、吸虫线粒体基因的研究意义及吸虫线粒体基因组研究的应用前景.

  16. Experimental infection with the small intestinal trematode, Haplorchis pumilio, in young dogs.

    Science.gov (United States)

    Nissen, Sofie; Nguyen, Lan Anh Thi; Dalsgaard, Anders; Thamsborg, Stig Milan; Johansen, Maria Vang

    2013-01-16

    Fishborne zoonotic trematodes (FZT) are highly prevalent in Southeast Asia. Recent studies on the role of domestic animals in the transmission of FZT in Northern Vietnam found that dogs, mainly infected with Haplorchis pumilio, contributed widely to the transmission of FZT. On this background, we conducted an experimental infection with H. pumilio to elucidate population dynamics and host reactions in dogs. Eight household-reared dogs (3-6 months old), were each orally infected with 500 H. pumilio metacercariae obtained by artificial digestion of naturally infected fish. Another eight dogs were included as uninfected controls. Faecal examination for eggs was performed twice weekly using a sieving and sedimentation technique. Body temperature and weight of the dogs were measured as was total white blood cells, blood eosinophils and packed cell volume. Subsets of dogs were examined post-mortem for presence of adult FZT at three different time points post infection by sectioning of the small intestine and caecum into four parts. Patent infections established in all eight infected dogs. The worm establishment ranged from 15 to 121 flukes (3-24%, mean 12%). Faecal egg excretion was measured in all eight infected dogs but no more than two eggs per g faeces (epg) were found at any time. Infections lasted for at least two months as documented by the presence of adult flukes in all three dogs necropsied on day 58 post infection. The predilection site of the flukes was identified as the lower part of jejunum (93% of total worm burden). The results of the haematological tests did not differ between the infected and uninfected group. Further, no clinical symptoms were observed in the infected group and no macroscopic pathological changes could be assigned to the trematode infections, neither did histopathological examination of the intestine reveal any differences between the infected and the control dogs. This study provides the first basic knowledge on the establishment

  17. Prevalence and pathology of the nematode Heterakis gallinarum, the trematode Paratanaisia bragai, and the protozoan Histomonas meleagridis in the turkey, Meleagris gallopavo.

    Science.gov (United States)

    Brener, Beatriz; Tortelly, Rogério; Menezes, Rodrigo Caldas; Muniz-Pereira, Luís C; Pinto, Roberto Magalhães

    2006-09-01

    The prevalence of infection and associated pathology induced by two helminth and one protozoan species infecting Brazilian turkeys are reported. The intestinal nematode Heterakis gallinarum appeared with a prevalence of 70% in the infected birds, without gross lesions when not associated to the protozoan Histomonas meleagridis. Histological findings in the ceca were represented by the presence of H. gallinarum worms, intense chronic diffuse inflammatory processes with mononuclear and polymorphonuclear (heterophils) leucocyte infiltrations. The prevalence of the protozoan H. meleagridis associated to H. gallinarum was of 2.5% and microscopic examination revealed a severe inflammatory process in the liver and cecum with the presence of small clear areas with round eosinophilic parasites. Gross lesions were absent in turkeys infected with the renal digenetic trematode Paratanaisia bragai; the parasite was prevalent in 20% of the cases and cross-sections of the kidneys showed a remarkable distension of the collecting ducts with several worms in the lumen. The walls of the ducts presented a discrete heterophilic infiltrate among mononuclear cells.

  18. Prevalence and pathology of the nematode Heterakis gallinarum, the trematode Paratanaisia bragai, and the protozoan Histomonas meleagridis in the turkey, Meleagris gallopavo

    Directory of Open Access Journals (Sweden)

    Beatriz Brener

    2006-09-01

    Full Text Available The prevalence of infection and associated pathology induced by two helminth and one protozoan species infecting Brazilian turkeys are reported. The intestinal nematode Heterakis gallinarum appeared with a prevalence of 70% in the infected birds, without gross lesions when not associated to the protozoan Histomonas meleagridis. Histological findings in the ceca were represented by the presence of H. gallinarum worms, intense chronic diffuse inflammatory processes with mononuclear and polymorphonuclear (heterophils leucocyte infiltrations. The prevalence of the protozoan H. meleagridis associated to H. gallinarum was of 2.5% and microscopic examination revealed a severe inflammatory process in the liver and cecum with the presence of small clear areas with round eosinophilic parasites. Gross lesions were absent in turkeys infected with the renal digenetic trematode Paratanaisia bragai; the parasite was prevalent in 20% of the cases and cross-sections of the kidneys showed a remarkable distension of the collecting ducts with several worms in the lumen. The walls of the ducts presented a discrete heterophilic infiltrate among mononuclear cells.

  19. [The influence of branchial parasitism by monogenoid trematodes on the development of Nile tilapia (Oreochromis niloticus) Linnaeus, 1757 bred in net-pond systems in Capivara Dam, PR].

    Science.gov (United States)

    Zanolo, Rodrigo; Leonhardt, Júlio Hermann; Silva e Souza, Angela Teresa; Yamamura, Milton Hissashi

    2009-01-01

    Tilapias are fish originally from Africa which nowadays are commercially bred in almost 100 countries, being one of the most commercially bred species in the world. In this work the trematode population of the monogenoidea group present in the branchiae of Nile tilapias bred in 4 net-ponds with volume of 4 m3 each, was monitored during 5 months. The juvenile fish, presenting initial average weight of 37.65 g originated from other piscicultures, were stocked in the density of 250 animals.m(-3) and monthly monitored until their commercialization, with final average weight of 485.4 g. The prevalence of these ectoparisites was high, between 90 and 100% in all months. The highest values of average intensity of infestation--AII and average abundance of infection--AAI occurred during the 2 first months of captivity, presenting a new increase in the last month of breeding. The only monogenoidea group present in the branchiae of the animals examined belonged to the Dactylogyridae family. The values of the dissolved oxygen, temperature, pH, nitrite and ammonia were within normal rate. In these conditions there were no significant differences between the relative condition factor--Kn among the parasited and non-parasited animals and also in the different levels of infestation, showing that, in these breeding conditions, the relationship parasite-host-environment presented itself in balance without causing great harm to the animals.

  20. In situ growth of juvenile cockles, Cerastoderma edule, experimentally infected with larval trematodes ( Himasthla interrupta)

    Science.gov (United States)

    Wegeberg, Anne Margrethe; Jensen, K. Thomas

    2003-08-01

    To examine the influence of larval trematodes (metacercariae) on survivorship and growth of bivalves, juvenile cockles were experimentally infected with Himasthla interrupta and afterwards deployed in enclosures on an intertidal flat at two different tidal levels for one month. The hypothesis is that the impact of such metacercariae varies with food availability and environmental conditions. The experimental cockles exhibited significantly different growth rates at the two study sites, but there was no discernible impact of the metacercariae on survivorship and shell-growth. Body condition, however, differed among infected and non-infected cockles at the site with the shortest immersion time. Both the experimentally infected and non-infected cockles lost body condition during their incubation in the laboratory because of starvation. Infected cockles, however, lost more flesh weight than the non-infected, and this difference was maintained for high-shore cockles during the in situ experiment, whereas both infected and non-infected low-shore cockles (living under more optimal food conditions) had regained their pre-experimental body condition. In conclusion, it seems that Himasthla interrupta metacercariae are non-exploitative and relatively harmless under moderate infection intensities and normal environmental conditions.

  1. Parasite manipulation of brain monoamines in California killifish (Fundulus parvipinnis) by the trematode Euhaplorchis californiensis

    Science.gov (United States)

    Shaw, J.C.; Korzan, W.J.; Carpenter, R.E.; Kuris, A.M.; Lafferty, K.D.; Summers, C.H.; Overli, O.

    2009-01-01

    California killifish (Fundulus parvipinnis) infected with the brain-encysting trematode Euhaplorchis californiensis display conspicuous swimming behaviours rendering them more susceptible to predation by avian final hosts. Heavily infected killifish grow and reproduce normally, despite having thousands of cysts inside their braincases. This suggests that E. californiensis affects only specific locomotory behaviours. We hypothesised that changes in the serotonin and dopamine metabolism, essential for controlling locomotion and arousal may underlie this behaviour modification. We employed micropunch dissection and HPLC to analyse monoamine and monoamine metabolite concentrations in the brain regions of uninfected and experimentally infected fish. The parasites exerted density-dependent changes in monoaminergic activity distinct from those exhibited by fish subjected to stress. Specifically, E. californiensis inhibited a normally occurring, stress-induced elevation of serotonergic metabolism in the raphae nuclei. This effect was particularly evident in the experimentally infected fish, whose low-density infections were concentrated on the brainstem. Furthermore, high E. californiensis density was associated with increased dopaminergic activity in the hypothalamus and decreased serotonergic activity in the hippocampus. In conclusion, the altered monoaminergic metabolism may explain behavioural differences leading to increased predation of the infected killifish by their final host predators. ?? 2008 The Royal Society.

  2. Tradeoff between establishing an infection and killing the host: response of snails ( Physa acuta) to a gradient of trematode (Halipegus eccentricus) exposures.

    Science.gov (United States)

    Gustafson, K D; Bolek, M G

    2015-02-01

    Pond snails ( Physa acuta ) were exposed to a gradient (0, 1, 3, 5, 10, 15, 20, 25, 30, 35, 40, and 50) of trematode (Halipegus eccentricus) eggs and observed to determine egg dose effects on the survival of snails through the prepatent period, snail reproduction, and the production of cercariae. The probability of snail survival through the prepatent period significantly decreased with increasing egg exposures, where the odds of snail survival was 0.94 per trematode egg. Similarly, the probability of snail reproduction significantly decreased with increasing egg exposures, where the odds of snail reproduction was 0.85 per trematode egg. In contrast, the probability of a snail shedding cercariae significantly increased with increasing egg exposures, where the odds of reaching a patent infection were 1.64 per trematode egg. However, snails shedding cercariae that were exposed to higher doses of trematode eggs tended to die sooner. Thus, there appears to be a tradeoff between infecting a snail and killing the host.

  3. MOLECULAR APPROACH TO THE STUDY OF TREMATODE PARASITES : THE BLOOD FLUKE

    Directory of Open Access Journals (Sweden)

    Philip T. LoVerde

    2012-09-01

    Full Text Available One important aspect of reproductive development in trematode parasites is the formation of a hardened eggshell which allows the zygote to develop into a miracidium in a hostile environment. The miracidium then can transfer the germline from the vertebrate host to snail intermediate host. Schistosome parasites, unlike other trematodes, have separate sexes and female reproductive development is known to depend on the presence of a male parasite. These facts make the blood flukes ideal material to study the mechanisms that underlie female reproductive development and eggshell formatian. We reasoned that the morphological and biochemical differences between the male and female must be reflected at the molecular level in the differential expression of sexually regulated genes. Radioactive single stranded cDNA was first transcribed from female RNA; and then sequences common to both male and female were removed by hybridization to an excess of male RNA. This probe was used to screen a cDNA library made from mRNA of adult worm paris. One hybridizing clone, pSMf 61-46, was shown to correspond to a 0.9 kilobase mRNA that is present only in mature female worms and is not detectable in female schistosomes from single-sex infections, in male worms or in eggs. Thus expression of the gene was female-specific. During normal bisexual infection this mRNA is first detected 28 days after infection (the time of worm pairing and increases to a high level at 35 days postinfection, coinciding with egg production. Thus the temporal expression of the gene was dependent on paining with male worm. The nucleotide sequence of the gene shows an open reading frame that encodes a 16 kDA polypeptide that shows strong homology with eggshell proteins on insects. A second female-specific cDNA clone, F-4, represents a 1.6 kilobase mRNA whose expression is also correlated with worm pairing and subsequent egg production, encodes a different putative eggshell component of 44 kDA. The

  4. MOLECULAR APPROACH TO THE STUDY OF TREMATODE PARASITES : THE BLOOD FLUKE

    Directory of Open Access Journals (Sweden)

    Philip T. LoVerde

    2012-09-01

    Full Text Available One important aspect of reproductive development in trematode parasites is the formation of a hardened eggshell which allows the zygote to develop into a miracidium in a hostile environment. The miracidium then can transfer the germline from the vertebrate host to snail intermediate host. Schistosome parasites, unlike other trematodes, have separate sexes and female reproductive development is known to depend on the presence of a male parasite. These facts make the blood flukes ideal material to study the mechanisms that underlie female reproductive development and eggshell formatian. We reasoned that the morphological and biochemical differences between the male and female must be reflected at the molecular level in the differential expression of sexually regulated genes. Radioactive single stranded cDNA was first transcribed from female RNA; and then sequences common to both male and female were removed by hybridization to an excess of male RNA. This probe was used to screen a cDNA library made from mRNA of adult worm paris. One hybridizing clone, pSMf 61-46, was shown to correspond to a 0.9 kilobase mRNA that is present only in mature female worms and is not detectable in female schistosomes from single-sex infections, in male worms or in eggs. Thus expression of the gene was female-specific. During normal bisexual infection this mRNA is first detected 28 days after infection (the time of worm pairing and increases to a high level at 35 days postinfection, coinciding with egg production. Thus the temporal expression of the gene was dependent on paining with male worm. The nucleotide sequence of the gene shows an open reading frame that encodes a 16 kDA polypeptide that shows strong homology with eggshell proteins on insects. A second female-specific cDNA clone, F-4, represents a 1.6 kilobase mRNA whose expression is also correlated with worm pairing and subsequent egg production, encodes a different putative eggshell component of 44 kDA. The

  5. Research progress on complete mitochondrial genome sequences and their application for trematodes%吸虫线粒体基因组及其应用研究进展

    Institute of Scientific and Technical Information of China (English)

    贾万忠; 闫鸿斌; 史万贵; 郭爱疆; 詹芳

    2011-01-01

    Trematodiases such as schistosomiasis and fascioliasis,a kind of the major parasitic zoonoses caused by the adult stage of trematodes, are prevalent in the world including China and have a global socioeconomic impact with morbidity and mortality in humans and domestic livestock. In this review,current progress,application and future development in studies on complete mitochondrial genomes of trematodes were summarized. To date, 14 full-length mi-tochondrial sequences of trematodes have been published including 10 species from Digenea and 4 species from Mono-genea. Analyses on nucleotide composition, gene arrangement, gene structures, genetic variations, and other features of trematode mt genomes will aid in investigations of mt functional and comparative genomics,molecular taxonomy, origin of species, evolution, phylogenetic tree, diagnosis of diseases and so on. Taxonomic position of newly found Schistosoma sinensium and Pagumogonimus bangkokensis, based on partial mitochondrial sequences, has been resolved. Likewise, compared with mitochondrial sequences from Paragonimus iloktsuenensis and P. Sadoensis shows they are a synonym of P. Ohirai. The coxl gene sequence of Fasiciola sp. From Japan is the same as that of F. Gigan-tica suggesting that they should be the same species. Moreover, nadl sequences from different isolates have a divergence of 8. 3% , meaning that cryptic species might exist within them. It becomes clear that mtDNAs are playing an important role in taxonomy and identification of trematodes and provide implications for the molecular epidemiologi-cal investigations and control of trematode infections.%吸虫病(Trematodiasis)如血吸虫病、肝片形吸虫病等是一类重要的人兽共患寄生虫病,在我国和世界各地普遍流行,危害严重.本文将对吸虫线粒体基因组全序列分析的研究进展、应用和今后的发展方向作一综述.目前,已完成包括复殖亚纲10个种和单殖亚纲4个种总计14种吸虫线

  6. Molecular assessment of trematode co-infection and intraspecific competition in molluscan intermediate hosts.

    Science.gov (United States)

    Thiele, Elizabeth A; Minchella, Dennis J

    2013-01-01

    molecular tool for the study of trematode life history variation in molluscan hosts.

  7. Gene structure of the two-domain taurocyamine kinase from Paragonimus westermani: evidence for a distinct lineage of trematode phosphagen kinases.

    Science.gov (United States)

    Jarilla, Blanca R; Tokuhiro, Shinji; Nagataki, Mitsuru; Uda, Kouji; Suzuki, Tomohiko; Acosta, Luz P; Agatsuma, Takeshi

    2013-07-11

    Taurocyamine kinase (TK) is an enzyme that catalyzes the reversible transfer of a phosphate between ATP and taurocyamine. Annelid TKs were suggested to have evolved from a CK ancestor. However, TKs from the lung fluke Paragonimus westermani comprised another lineage. Construction of phylogenetic tree and comparison of exon/intron organization showed that P. westermani TK and other trematode TKs evolved from a molluscan arginine kinase (AK) gene. Exon shuffling probably caused the changes in amino acid sequence thereby changing the affinity from AK to TK. The present study provides new insights on the evolution of phosphagen kinases found in trematodes.

  8. Determination of the infection of Lymnaea-gedrosina to trematodes Larval in the water region of Khuzestan

    Directory of Open Access Journals (Sweden)

    Shamsi Noorpisheh

    2011-06-01

    Full Text Available Background & Objective: The province of Khuzestan with its wide geographical area and its tropical climate is susceptible for the maintenance of snails. One of the prevalent intermediate hosts for trematode in this area is the gasteropode snail, Lymnaea gedrosina. This study is the first research, undertaken to determine the infection rate, biological characteristics and Longevity Lymnaea gedrosina. Materials & Methods: A total of 6213 snails (Lymnaea gedrosina were examined, 770 snails were kept in identical natural condition in a set of several water bodies. Using two methods of cercarial shedding by light and crushing of snails were identified. Results: Overall, 107 snails (5% were infected with trematodes larval. The maximum and minimum infection rate Maravaneh 4, (44% - Ahvaz, Dezfull including Anjirak and Sidnoor (1.7% and 1% respectively. In addition, the maximum and minimum longevity time per Lymnaea gedrosina were respectively found to be in the spring and autumn. Conclusion: The results of this study could be utilized to plan control intermediate disease snails for the purpose of sanitation in the Khuzestan Province.

  9. Effect of pond water depth on snail populations and fish-borne zoonotic trematode transmission in juvenile giant gourami (Osphronemus goramy) aquaculture nurseries.

    Science.gov (United States)

    Thien, P C; Madsen, H; Nga, H T N; Dalsgaard, A; Murrell, K D

    2015-12-01

    Infection with fish-borne zoonotic trematodes (FZT) is an important public health problem in many parts of Southeast Asia. People become infected with FZT when eating raw or undercooked fish that contain the infective stage (metacercariae) of FZT. The parasites require specific freshwater snails as first intermediate host and a variety of fish species, both wild caught and cultured, as second intermediate host. Aquaculture production has grown almost exponentially in SE Asia and in order to produce fish free from FZT metacercariae, it is important to mitigate factors promoting transmission to fish. Here we report results from a cross-sectional study to look at the association between pond depth and infection with FZT in giant gourami nursery ponds. Density of intermediate host snails was positively associated with pond depth (count ratio associated with a 1m increase in pond depth was 10.4 (95% C.L.: 1.61-67.1, p200 fry m(-3)) was associated with lower host snail density (count ratio=0.15) than low stocking density (<100 fry m(3)). Ponds stocked with 100-200 fry m(-3) had snail counts 0.76 (95% C.L.: 0.33-1.75, p n.s.) of those in ponds stocked with fry density of <100 fry m(-3). Since density of intermediate snail hosts was associated with FZT transmission to fish, effort should be taken to reduce snail density prior to stocking the fry, but focus should also be on habitats surrounding ponds as transmission may occur through cercariae produced outside ponds and carried into ponds with water pumped into ponds.

  10. On the systematic position of Collyricloides massanae Vaucher, 1969 (Platyhelminthes: Digenea) with notes on distribution of this trematode species.

    Science.gov (United States)

    Kanarek, Gerard; Zaleśny, Grzegorz; Czujkowska, Agnieszka; Sitko, Jiljí; Harris, Philip D

    2015-04-01

    The systematic position of the Collyricloides massanae, a rare cyst-dwelling parasite, located on intestinal wall of European birds and rodents, have always been controversial. Based on newly obtained sequences of the 28 sDNA of C. massanae from avian and rodent host from Central Europe, and on the previously published sequences of several genera and families among Microphalloidea, we evaluate its taxonomic position and the phylogenetic relationships within the genera Collyriclum Kossack, 1911 and Collyricloides Vaucher, 1969 which form the family Collyriclidae Ward, 1917. In the cladogram, C. massanae appears among the Pleurogenidae, forming a clade with Gyrabascus amphoraeformis (Modlinger, 1930) and Cortrema magnicaudata (Bykhovskaya-Pavlovskaya, 1950). We reject the commonly accepted placement of Collyricloides as the sister genus to Collyriclum within the Collyriclidae. Besides, we present and discuss the unusual records of C. massanae in the bank vole Myodes glareolus from northeastern Poland.

  11. Comparison of carbon and nitrogen content of infected and uninfected snails, Succinea ovalis, and the trematode Leucochloridium variae.

    Science.gov (United States)

    Burky, A J; Hornbach, D J

    1979-06-01

    In June, 6.7% of adult Succinea ovalis collected near Urbana, Ohio, were infected with the trematode, Leucochloridium variae. The effects of parasitism were assessed as total organic carbon (equivalent to calorific values) and as total nitrogen. The parasite represents 23.8% of total (parasite + snail tissue) dry tissue weight, 21.4% of total carbon and 19.8% of total nitrogen of infected snails. The higher C : N ratio for parasite tissue indicates a higher proportion of nonproteinaceous compounds (e.g., fats and/or carbohydrates) as compared to host tissue. There is less snail tissue in parasited S. ovalis. The C : N ratios for parasitized and nonparasitized snail tissue suggest identical percentage compositions of proteins, fats, and carbohydrates.

  12. Geomapping of trematode-induced granulomatous anterior uveitis - a newly identified cause of blindness among children in the Pudukkottai district of the Tamil Nadu State, India

    Directory of Open Access Journals (Sweden)

    Jayakumar Duraisamy

    2009-11-01

    Full Text Available There is evidence that a specific type of allergic conjunctive-uveal granuloma reported from South India could be due to infection by a trematode parasite. In these patients, the histopathological examination of the eye reveals a zonal granulomatous inflammation with purulent material including structures displaying evidence of trematode infection. To investigate this further, medical records describing such cases in the Pudukkottai district, Tamil Nadu State, India, covering the period 2001-2005, were collected. Since trematodes require a snail intermediate host for completing the life cycle, ponds frequently used for bathing in the area were inspected to identify a possible culprit. The hypothesis that ponds with snail habitats could be the source of infection was supported by the finding of a positive correlation between the geographical distribution of patients’ residencies and the location of such ponds. Geographic information systems (GIS were used to study the spatial distribution of ponds and patients, while satellite-based remote sensing (RS was applied to attempt finding a parameter characteristic for ponds with snail habitats that could facilitate risk-identification over larger areas. It was found that ponds carrying risk could be differentiated from others through analysis of their spectral surface properties. This pond classification approach, confirmed by field visits, could thus become a useful tool for the location of snail habitats constituting risk as predicted.

  13. Podocotyle nimoyi n. sp. (Digenea: Opecoelidae: Plagioporinae) and a re-description of Podocotyle pearsei Manter, 1934 from five species of deep-sea macrourids from the Gulf of Mexico and Caribbean Sea.

    Science.gov (United States)

    Blend, Charles K; Dronen, Norman O; Armstrong, Howard W

    2016-06-02

    Two rare species of Podocotyle Dujardin, 1845 (Digenea: Opecoelidae) parasitizing five macrourid species inhabiting the deep waters of the northeastern Gulf of Mexico and Caribbean Sea off Panama are described. Podocotyle nimoyi n. sp. was found in the intestine of the pugnose grenadier, Sphagemacrurus grenadae (Parr), and the common Atlantic grenadier, Nezumia aequalis (Günther) (Gadiformes: Macrouridae), at depths of 534-995 m in the Northeast Gulf of Mexico off Florida and represents the fifth species of Podocotyle endemic to the deep sea. Podocotyle pearsei Manter, 1934, was re-described from the intestine of the bullseye grenadier, Bathygadus macrops Goode & Bean, the doublethread grenadier, Gadomus arcuatus (Goode & Bean), and the western softhead grenadier, Malacocephalus occidentalis Goode & Bean (Gadiformes: Macrouridae), collected from 591-728 m depths in the Northeast Gulf of Mexico off Florida and the Caribbean Sea off Panama. The following new host records are established: P. nimoyi n. sp. is the third parasite species known from S. grenadae and the first digenean species reported from this host; P. nimoyi n. sp. is the first reported species of Podocotyle parasitizing N. aequalis; and this is the first report of P. pearsei or any representative of the genus Podocotyle infecting B. macrops, G. arcuatus and M. occidentalis. A listing of all digenean parasites previously reported from the five macrourid species examined herein is given and some observations are made about Podocotyle in the deep sea.

  14. Experimental test of host specificity in a behaviour-modifying trematode

    DEFF Research Database (Denmark)

    Hernandez, R.N.; Fredensborg, Brian Lund

    2015-01-01

    natural brain infections of Euhaplorchis sp. A metacercariae in three cyprinids in the shallow sublittoral zone. Of the three experimentally exposed species, Fundulus grandis and Poecilia latipinna acquired infections and displayed an elevated number of conspicuous behaviours in comparison with uninfected...

  15. Occurrence and intensity of parasites in Wels catfish, Silurus glanis L. 1758 from Amirkelayeh wetland, southwest of the Caspian Sea.

    Science.gov (United States)

    Khara, Hossein; Sattari, Masoud

    2016-09-01

    Amirkelayeh international wetland with a surface area of 1,230 hectares and fifteen fish species is an important water resource in the southern part of the Caspian Sea. There is few reports on fish parasites of this area. In the present study, a total of 80 Wels catfish, Silurus glanis, were collected from April through July 2011. After recording biometric characteristics, common necropsy and parasitology methods were used. In the present study, a total of 441 individuals of seven parasite species consisting of one nematode: Raphidascaroides sp., one cestode: Triaenophorus crassus, two digenean trematodes: Aphanurus stossichi and Diplostomum spathaceum, two monogenean trematodes: Silurodiscoides vistulensis and Silurodiscoides siluri, and one crustacean: copepodid stage of Lernaea cyprinacea was found in the catfish. The occurrence of copepodid stage of L. cyprinacea, Raphidascaroides sp. and T. crassus are reported for the first time from S. glanis in Iran.

  16. Learned parasite avoidance is driven by host personality and resistance to infection in a fish-trematode interaction.

    Science.gov (United States)

    Klemme, Ines; Karvonen, Anssi

    2016-09-14

    Cognitive abilities related to the assessment of risk improve survival. While earlier studies have examined the ability of animals to learn to avoid predators, learned parasite avoidance has received little interest. In a series of behavioural trials with the trematode parasite Diplostomum pseudospathaceum, we asked whether sea trout (Salmo trutta trutta) hosts show associative learning in the context of parasitism and if so, whether learning capacity is related to the likelihood of infection mediated through host personality and resistance. We show that animals are capable of learning to avoid visual cues associated with the presence of parasites. However, avoidance behaviour ceased after the likely activation of host resistance following consecutive exposures during learning, suggesting that resistance to infection outweighs avoidance. Further, we found a positive relationship between learning ability and boldness, suggesting a compensation of risky lifestyles through increased investment in cognitive abilities. By contrast, an increased risk of infection due to low resistance was not balanced by learning ability. Instead, these traits were positively related, which may be explained by inherent physiological qualities controlling both traits. Overall, the results demonstrate that parasitism, in addition to other biological interactions such as predation, is an important selective factor in the evolution of animal cognition. © 2016 The Author(s).

  17. Surgical removal of cataracts due to Diplostomum species in Gulf sturgeon (Acipenser oxyrinchus desotoi).

    Science.gov (United States)

    Bakal, Robert S; Hickson, Brian H; Gilger, Brian C; Levy, Michael G; Flowers, James R; Khoo, Lester

    2005-09-01

    Twenty 6-yr-old (1995-yr-class) Gulf of Mexico sturgeon (Acipenser oxyrinchus desotoi) were diagnosed as having bilateral cataracts. Histopathologic assessment of the lenses of two of the fish revealed the presence of a diplostomid trematode. Pharmacological treatment of the trematodes may be effective for killing the parasites, but the damage to the lenses and resulting cataracts are nonreversible. Because these animals were to be used in a subsequent study as sentinels in the natural environment, it was necessary to return the animals' vision to as close to normal as possible. Electroretinograms were performed on each fish's eyes to ensure that retinal function was present. Cataracts then were surgically removed by phacoemulsification and aspiration. The animals tolerated the surgical procedures well. This report is the first known report of surgical correction of cataracts in sturgeon species. It also is the first known attempt to correct vision problems in fish being returned to the wild.

  18. A digenean parasite in a mudskipper: Opegaster ouemoensis sp. n. (Digenea: Opecoelidae) in Periophthalmus argentilineatus Valenciennes (Perciformes: Gobiidae) in the mangroves of New Caledonia.

    Science.gov (United States)

    Bray, Rodney A; Justine, Jean-Lou

    2013-02-01

    Opegaster ouemoensis sp. n. is described from Periophthalmus argentilineatus Valenciennes (Gobiidae). Distinctive features included the weak or undetectable papillae of the ventral sucker and the small, but distinct cirrus-sac. The new species is compared with 25 marine species of Opegaster for which a table of measurements and ratios is presented. The new combination Opegaster queenslandicus (Aken'Ova, 2007) (originally in Opecoelus) is formed. Fifteen mudskippers were intensively examined for parasites; larval anisakid nematodes and acanthocephalans were found, but no monogeneans, cestodes, copepods, isopods, hirudineans or adult nematodes. A brief summary of the helminth parasites of mudskippers is included.

  19. Prey species and size choice of the molluscivorous fish, black carp (Mylopharyngodon piceus)

    DEFF Research Database (Denmark)

    Hung, N. M.; Stauffer, J. R.; Madsen, Henry

    2013-01-01

    ponds in northern Vietnam. Furthermore, shell strength of common snails was assessed. Average daily consumption as percentage of fish weight ranged from 8.12% for smaller fish (100-250 g) to 4.68% in the larger fish (610-1250 g). Bithynia fuchsiana, the intermediate host of Clonorchis sinensis, and some...... intestinal trematodes were readily consumed by even the smallest black carp tested. The proportion of Melanoides tuberculata, an important host for intestinal trematodes, declined with an increase in its shell height. The same was observed for two viviparid snail species, Angulyagra polyzonata and Sinotaia......, to control snails serving as first intermediate hosts. However, the use of large juvenile (>2 kg) black carp in nursery ponds could be problematic and we decided to determine consumption rates by black carp of various sizes and their choice of different sizes of selected snail species found in aquaculture...

  20. PREVALENCE OF ENDO (TREMATODES AND ECTO-PARASITES IN COWS AND BUFFALOES OF QUETTA, PAKISTAN

    Directory of Open Access Journals (Sweden)

    M. N. KAKAR AND J. K. KAKARSULEMANKHEL1

    2008-01-01

    Full Text Available Prevalence of endo and ecto-parasites in cows and buffaloes were investigated in Quetta city, Pakistan. A total of 396 livers and gall bladders of cows and 340 of buffaloes were selected randomly. Overall prevalence of liver parasites in cows and buffaloes was 45.70 and 37.05%, respectively. The species found in livers of cows were: Fasciola hepatica (16.16%, Fasciola gigantica (12.37%, Paramphistomum explanatum (7.82% and mixed infections (9.34%. The corresponding values for buffaloes were 11.47, 13.52, 5.58 and 6.47%. For ecto-parasites, out of 404 cows and 386 buffaloes examined, 28.96 and 25.64% respectively gave positive results for ecto-parasites. The prevalence of ticks, lice, mites and mixed infection was found to be 10.14, 7.17, 5.19 and 6.43%, respectively in cows and 6.99, 9.84, 4.92 and 3.88% respectively in buffaloes. It was concluded that the prevalence of endo and ecto-parasites in cows was higher than in buffaloes due to differences in feeding habits and hygienic habitats of the two species.

  1. [Changes produced by trematode larvae in the phospholipid fatty acid composition of digestive gland of the mollusc Littorina saxatilis].

    Science.gov (United States)

    Arakelova, E S; Chebotareva, M A; Zabelinskiĭ, S A; Shukoliukova, E P

    2007-01-01

    Lipids of the digestive gland of the mollusc Littorina saxatilis from the White and Barents Seas were studied. Changes of its biochemical composition are discussed in the connection with different temperature of the habitat and with infestation with trematode larvae. Comparative analysis of the fatty acid (FA) composition of each of phospholipids in intact molluscs has revealed essential differences. Phosphatidylcholine and monophosphatidylinositol (MPI) FA did not differ in the omega 3/omega 6 ratio, which is due to their tolerance to the temperature factor, whereas more unsaturated phospholipids--phosphatidylethanolamine (FEA), its plasmalogen form (pFEA), and phosphatidylserine--differed 1.5-2 times in the studied molluscs. Predominance of omega 3 acids in the Borents Sea molluscs undoubtedly is due to the lower habitat temperatures, as it provides a higher fluidity of membrane phospholipids. Infestation affected to the greatest degree the quantitative FA composition in pFEA and MPI. At infestation, out of all considered phospholipids, only in MPI there was revealed a threefold decrease of the content of eikosenoic acid C20 : 1, whereas in all other phospholipids, in the contrary, it increased. Monophosphatidylinositols also differed essentially from other phospholipids by the saturated FA amount, which changed the unsaturation index of these phospholipids. Since the functional significance of this minor phospholipid is determined by its participation in the so-called phosphatidylinositol system of the hormonal signal transduction, it seems interesting to elucidate whether an increase of this membrane phospholipid saturation at invasion affects the reflex connection between signals from receptors located in a parasite and enzymatic processes.

  2. A new brachycladiid species (Digenea) from Gervais' beaked whale Mesoplodon europaeus in north-western Atlantic waters.

    Science.gov (United States)

    Fraija-Fernández, Natalia; Aznar, Francisco J; Raga, Juan A; Gibson, David; Fernández, Mercedes

    2014-09-01

    A new species of the digenean family Brachycladiidae Odhner, 1905 is described from the bile ducts of a Gervais' beaked whale Mesoplodon europaeus Gervais (Ziphiidae) stranded on the North Atlantic coast of Florida. These parasites were assigned to Brachycladium Looss, 1899 and differed from other species of the genus in the relative size of the oral and ventral suckers, the form and size of the eggs and their extremely small body size. A canonical discriminant analysis was used to examine differences between these specimens and the smallest available individuals of B. atlanticum (Abril, Balbuena and Raga, 1991) Gibson, 2005, considered the morphologically closest species. The overall results exhibited significant differences between the two samples and a jack-knife classification showed that 96.2% of the specimens were correctly classified to their group. In view of evidence from morphological data, the specimens from M. europaeus are considered as new to science and are designated as Brachycladium parvulum n. sp.

  3. In vivo and in vitro effects of the herbicide Roundup(®) on developmental stages of the trematode Echinostoma paraensei.

    Science.gov (United States)

    Monte, Tainá C de C; Garcia, Juberlan; Gentile, Rosana; de Vasconcellos, Maurício Carvalho; Souza, Joyce; Braga, Brunna V; Maldonado, Arnaldo

    2016-10-01

    The exposure of wildlife and humans to toxic residues of Roundup(®) through agricultural practices or the food chain has been reported since the herbicide was found contaminating rivers. Glyphosate, N-(phosphonomethyl)glycine acid, is a nonselective post-emergent herbicide and is formulated as an isopropylamine salt with the surfactant taloamine polyethoxylate (POEA) representing the commercial formulation of Roundup(®). There is little knowledge about the effects of the herbicide on helminth parasites, particularly those whose life cycle is related to water bodies. Here we investigated the effects of the Roundup(®) on the food-borne trematode Echinostoma paraensei in experimental conditions using different developmental stages (eggs, miracidia, cercariae, metacercariae, newly excysted larvae (NEL), helminths at seven days and helminths at fourteen days). Three different herbicide concentrations were tested based on concentrations typically applied in the field: 225, 450 and 900 mg/L. Specimens were analyzed in vitro for hatching miracidia, mortality and excystment rate of metacercariae and in vivo for parasitic load and egg production. There was a significant difference in the hatching miracidia rate only for the newly embryonated eggs. The mortality of specimens and excystment rate of metacercariae were concentration-dependent. There was a significant difference in the miracidia mortality with respect to concentration until 56.3 mg/L. The same effect was observed for cercariae, and mortality was observed from 15 min onwards at concentrations of 225-900 mg/L. At low concentrations, mortality was detected after 30 min. The effects of the herbicide concentration on NEL and on helminths at seven and fourteen days showed a significant difference after 24 h. There was no significant difference in parasitic load and egg production after infection of rodents with exposed metacercariae. All developmental stages of the trematode E. paraensei were affected by

  4. Anthelmintic Effect of Bacillus thuringiensis Strains against the Gill Fish Trematode Centrocestus formosanus

    Directory of Open Access Journals (Sweden)

    Luis Javier Mendoza-Estrada

    2016-01-01

    Full Text Available Parasitic agents, such as helminths, are the most important biotic factors affecting aquaculture, and the fluke Centrocestus formosanus is considered to be highly pathogenic in various fish species. There have been efforts to control this parasite with chemical helminthicides, but these efforts have had unsuccessful results. We evaluated the anthelmintic effect of 37 strains of Bacillus thuringiensis against C. formosanus metacercariae in vitro using two concentrations of total protein, and only six strains produced high mortality. The virulence (CL50 on matacercariae of three strains was obtained: the GP308, GP526, and ME1 strains exhibited a LC50 of 146.2 μg/mL, 289.2 μg/mL, and 1721.9 μg/mL, respectively. Additionally, these six B. thuringiensis strains were evaluated against the cercariae of C. formosanus; the LC50 obtained from the GP526 strain with solubilized protein was 83.8 μg/mL, and it could be considered as an alternative control of the metacercariae and cercariae of this parasite in the productivity systems of ornamental fishes.

  5. Anthelmintic Effect of Bacillus thuringiensis Strains against the Gill Fish Trematode Centrocestus formosanus

    Science.gov (United States)

    Mendoza-Estrada, Luis Javier; Hernández-Velázquez, Víctor Manuel; Arenas-Sosa, Iván; Flores-Pérez, Fernando Iván; Morales-Montor, Jorge; Peña-Chora, Guadalupe

    2016-01-01

    Parasitic agents, such as helminths, are the most important biotic factors affecting aquaculture, and the fluke Centrocestus formosanus is considered to be highly pathogenic in various fish species. There have been efforts to control this parasite with chemical helminthicides, but these efforts have had unsuccessful results. We evaluated the anthelmintic effect of 37 strains of Bacillus thuringiensis against C. formosanus metacercariae in vitro using two concentrations of total protein, and only six strains produced high mortality. The virulence (CL50) on matacercariae of three strains was obtained: the GP308, GP526, and ME1 strains exhibited a LC50 of 146.2 μg/mL, 289.2 μg/mL, and 1721.9 μg/mL, respectively. Additionally, these six B. thuringiensis strains were evaluated against the cercariae of C. formosanus; the LC50 obtained from the GP526 strain with solubilized protein was 83.8 μg/mL, and it could be considered as an alternative control of the metacercariae and cercariae of this parasite in the productivity systems of ornamental fishes. PMID:27294137

  6. A Trematode Parasite Derived Growth Factor Binds and Exerts Influences on Host Immune Functions via Host Cytokine Receptor Complexes

    Science.gov (United States)

    Sulaiman, Azad A.; Zolnierczyk, Katarzyna; Japa, Ornampai; Owen, Jonathan P.; Maddison, Ben C.; Hodgkinson, Jane E.; Gough, Kevin C.

    2016-01-01

    The trematode Fasciola hepatica is responsible for chronic zoonotic infection globally. Despite causing a potent T-helper 2 response, it is believed that potent immunomodulation is responsible for rendering this host reactive non-protective host response thereby allowing the parasite to remain long-lived. We have previously identified a growth factor, FhTLM, belonging to the TGF superfamily can have developmental effects on the parasite. Herein we demonstrate that FhTLM can exert influence over host immune functions in a host receptor specific fashion. FhTLM can bind to receptor members of the Transforming Growth Factor (TGF) superfamily, with a greater affinity for TGF-β RII. Upon ligation FhTLM initiates the Smad2/3 pathway resulting in phenotypic changes in both fibroblasts and macrophages. The formation of fibroblast CFUs is reduced when cells are cultured with FhTLM, as a result of TGF-β RI kinase activity. In parallel the wound closure response of fibroblasts is also delayed in the presence of FhTLM. When stimulated with FhTLM blood monocyte derived macrophages adopt an alternative or regulatory phenotype. They express high levels interleukin (IL)-10 and arginase-1 while displaying low levels of IL-12 and nitric oxide. Moreover they also undergo significant upregulation of the inhibitory receptor PD-L1 and the mannose receptor. Use of RNAi demonstrates that this effect is dependent on TGF-β RII and mRNA knock-down leads to a loss of IL-10 and PD-L1. Finally, we demonstrate that FhTLM aids newly excysted juveniles (NEJs) in their evasion of antibody-dependent cell cytotoxicity (ADCC) by reducing the NO response of macrophages—again dependent on TGF-β RI kinase. FhTLM displays restricted expression to the F. hepatica gut resident NEJ stages. The altered fibroblast responses would suggest a role for dampened tissue repair responses in facilitating parasite migration. Furthermore, the adoption of a regulatory macrophage phenotype would allow for a reduced

  7. A Trematode Parasite Derived Growth Factor Binds and Exerts Influences on Host Immune Functions via Host Cytokine Receptor Complexes.

    Directory of Open Access Journals (Sweden)

    Azad A Sulaiman

    2016-11-01

    Full Text Available The trematode Fasciola hepatica is responsible for chronic zoonotic infection globally. Despite causing a potent T-helper 2 response, it is believed that potent immunomodulation is responsible for rendering this host reactive non-protective host response thereby allowing the parasite to remain long-lived. We have previously identified a growth factor, FhTLM, belonging to the TGF superfamily can have developmental effects on the parasite. Herein we demonstrate that FhTLM can exert influence over host immune functions in a host receptor specific fashion. FhTLM can bind to receptor members of the Transforming Growth Factor (TGF superfamily, with a greater affinity for TGF-β RII. Upon ligation FhTLM initiates the Smad2/3 pathway resulting in phenotypic changes in both fibroblasts and macrophages. The formation of fibroblast CFUs is reduced when cells are cultured with FhTLM, as a result of TGF-β RI kinase activity. In parallel the wound closure response of fibroblasts is also delayed in the presence of FhTLM. When stimulated with FhTLM blood monocyte derived macrophages adopt an alternative or regulatory phenotype. They express high levels interleukin (IL-10 and arginase-1 while displaying low levels of IL-12 and nitric oxide. Moreover they also undergo significant upregulation of the inhibitory receptor PD-L1 and the mannose receptor. Use of RNAi demonstrates that this effect is dependent on TGF-β RII and mRNA knock-down leads to a loss of IL-10 and PD-L1. Finally, we demonstrate that FhTLM aids newly excysted juveniles (NEJs in their evasion of antibody-dependent cell cytotoxicity (ADCC by reducing the NO response of macrophages-again dependent on TGF-β RI kinase. FhTLM displays restricted expression to the F. hepatica gut resident NEJ stages. The altered fibroblast responses would suggest a role for dampened tissue repair responses in facilitating parasite migration. Furthermore, the adoption of a regulatory macrophage phenotype would allow

  8. Two-year intervention trial to control of fish-borne zoonotic trematodes in giant gourami (Osphronemus goramy) and striped catfish (Pangasianodon hypophthalmus) in nursery ponds in the Mekong Delta, Vietnam.

    Science.gov (United States)

    Madsen, H; Thien, P C; Nga, H T N; Clausen, J H; Dalsgaard, A; Murrell, K D

    2015-12-01

    Fish-borne zoonotic trematode parasites (FZT) pose a food safety and public health problem in Vietnam. The transmission cycle is complex as domestic animals, especially dogs, cats, fish-eating birds and pigs together with humans serve as reservoir hosts and contribute to FZT egg contamination of aquaculture ponds and the environment. This intervention trial was conducted to determine the effectiveness of various on-farm interventions, including reduction in FZT egg contamination through treatment of infected people and domestic animals, reduction in snail density through mud removal from aquaculture ponds prior to fish stocking, and various other measures in reducing FZT infection in juvenile striped catfish (Pangasianodon hypophthalmus) and giant gourami (Osphronemus goramy). Interventions were implemented on 5 farms for each fish species during production cycles in 2009 and 2010 while 5 similar farms for each species served as control. For both fish species, both prevalence and intensity of infection did not differ significantly between intervention and non-intervention farms prior to the interventions. The interventions significantly reduced both prevalence and intensity of FZT infection in the juvenile fish compared to control ponds. For giant gourami, odds of infection in intervention ponds was 0.13 (95% CL: 0.09-0.20; p<0.001) of that in non-intervention ponds after the 2009 trial and 0.07 (0.03-0.14; p<0.001) after the 2010 trial. For striped catfish, these figures were 0.17 (0.08-0.35; p<0.001) after the 2009 trial while after the 2010 trial all ponds with interventions were free from infection. Metacercariae intensity (no. of metacercariae/fish) in giant gourami from intervention ponds was 0.16 (0.11-0.23; p<0.001) of that in fish from non-intervention ponds after the 2009 trial and 0.07 (0.04-0.15; p<0.001) after the 2010 trial; for striped catfish these figures were 0.18 (0.09-0.36; p<0.001) and 0.00 (confidence limits not estimated), respectively. The

  9. Testing the enemy release hypothesis: abundance and distribution patterns of helminth communities in grey mullets (Teleostei: Mugilidae) reveal the success of invasive species.

    Science.gov (United States)

    Sarabeev, Volodimir; Balbuena, Juan Antonio; Morand, Serge

    2017-09-01

    The abundance and aggregation patterns of helminth communities of two grey mullet hosts, Liza haematocheilus and Mugil cephalus, were studied across 14 localities in Atlantic and Pacific marine areas. The analysis matched parasite communities of (i) L. haematocheilus across its native and introduced populations (Sea of Japan and Sea of Azov, respectively) and (ii) the introduced population of L. haematocheilus with native populations of M. cephalus (Mediterranean, Azov-Black and Japan Seas). The total mean abundance (TMA), as a feature of the infection level in helminth communities, and slope b of the Taylor's power law, as a measure of parasite aggregation at the infra and component-community levels, were estimated and compared between host species and localities using ANOVA. The TMA of the whole helminth community in the introduced population of L. haematocheilus was over 15 times lower than that of the native population, but the difference was less pronounced for carried (monogeneans) than for acquired (adult and larval digeneans) parasite communities. Similar to the abundance pattern, the species distribution in communities from the invasive population of L. haematocheilus was less aggregated than from its native population for endoparasitic helminths, including adult and larval digeneans, while monogeneans showed a similar pattern of distribution in the compared populations of L. haematocheilus. The aggregation level of the whole helminth community, endoparasitic helminths, adult and larval digeneans was lower in the invasive host species in comparison with native ones as shown by differences in the slope b. An important theoretical implication from this study is that the pattern of parasite aggregation may explain the success of invasive species in ecosystems. Because the effects of parasites on host mortality are likely dose-dependent, the proportion of susceptible host individuals in invasive species is expected to be lower, as the helminth distribution in

  10. Trematode reproduction in the molluscan host: an ultrastructural study of the germinal mass in the rediae of Himasthla elongata (Mehlis, 1831) (Digenea: Echinostomatidae).

    Science.gov (United States)

    Podvyaznaya, Irina M; Galaktionov, Kirill V

    2014-03-01

    The germinal mass in Himasthla elongata rediae was studied in detail using transmission electron microscopy. It was shown to be a specialized reproductive organ consisting of germinal cells at various maturation stages, supporting cells and stem cells. The germinal mass also contains early cercarial embryos emerging as a result of cleavage division of mature germinal cells. The stem cells that give rise to germinal cells have heterochromatin-rich nuclei with distinct nucleoli and scarce cytoplasm containing mainly free ribosomes and few mitochondria. The differentiating germinal cells undergo a growth, which is accompanied by an emergence of annulate lamellae and the nuage in their cytoplasm, a noticeable development of RER and Golgi apparatus and an increase in the number of mitochondria. The mitochondria form a large group at one of the cell poles. During differentiation, the nucleus and nucleolus of the germinal cell enlarge while the chromatin becomes gradually less condensed. The supporting tissue of the germinal mass is made up of cells connected by septate junctions. These supporting cells are distinctly different in cellular shape and nuclear ultrastructure. Their outgrowths form a tight meshwork housing stem cells, germinal cells and early cercarial embryos. The cytoplasm of the supporting cells in the mesh area is separated into fine parallel layers by labyrinthine narrow cavities communicating with the intercellular space. The supporting tissue contains differentiating and degenerating cells which indicates its renewal. The results of this ultrastructural study lend support to the hypothesis that the germinal cells of digeneans are germ line cells.

  11. Evidence of new species of Haematoloechus (Platyhelminthes: Digenea) using partial cox1 sequences.

    Science.gov (United States)

    León-Règagnon, Virginia

    2010-12-01

    Haematoloechus, digeneans parasites of amphibians, is a species-rich genus with more than 50 species around the globe. Establishing an accurate taxonomy for this group has been difficult due to high intraspecific variability. Nuclear DNA sequences have given independent information about species validity and phylogeny of the group. In this paper, I test the performance of partial sequences of the mitochondrial cytochrome c oxidase subunit I (cox1) gene in the differentiation of recognized species of the genus and in the detection of potential new taxa. Samples from 13 nominal species were sequenced, plus four samples that could not be assigned to any described species based on morphology. Parsimony analysis of the amplified 360 bp fragment resulted in six most parsimonious trees showing the same grouping of samples, differing in the samples' arrangement within those groups. All 13 species were recovered on the trees, and five potential new species are shown. Additional sampling and sequencing is necessary to support this hypothesis, but with this preliminary information the search for diagnostic characters that allow the description of the new taxa is less difficult.

  12. Helminth communities of two species of piscivorous birds, Ardea alba (Linnaeus) and Nyctanassa violacea (Gmelin) (Ciconiiformes: Ardeidae), in two coastal lagoons from Guerrero state, Mexico.

    Science.gov (United States)

    Violante-González, Juan; Monks, Scott; Gil-Guerrero, Salvador; Rojas-Herrera, Agustín A; Flores-Rodríguez, Pedro

    2012-07-01

    The composition and species richness in helminth communities of two species of heron, Ardea alba and Nyctanassa violacea, in two coastal lagoons from Guerrero, Mexico were examined. Nineteen species of helminth (7,804 individuals) were identified in 43 adult birds: 15 digeneans, 1 acanthocephalan, 1 cestode, and 2 nematodes. Eight species co-occurred in herons of both species and lagoons. The prevalence values of seven species and the mean abundance of five species varied significantly between species of birds and between lagoons. The heterophyid, Ascocotyle (Phagicola) longa, was the helminth numerically dominant in the helminth community of A. alba in both lagoons, while the cestode, Parvitaenia cochlearii, dominated the community of N. violacea. At the component community level, species richness varied significantly: 10 species in A. alba from Coyuca to 16 in N. violacea (Tres Palos). All of the birds examined were infected with helminth parasites: three to seven species per host in A. alba from Coyuca, and two to eight species in A. alba and N. violacea from Tres Palos. The results indicate that even though species composition was similar between both species of heron, the structure of their communities was not the same. Differences in the feeding behavior of the birds (day/night habits), as well as local differences in the abundance of species of fish, and infection levels of helminths in each lagoon are suggested as being responsible for the variations registered in the structure of the helminth communities.

  13. Mercury in parasitic nematodes and trematodes and their double-crested cormorant hosts: Bioaccumulation in the face of sequestration by nematodes

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Stacey A., E-mail: srobinsc@connect.carleton.ca [Department of Biology, Carleton University, 209 Nesbitt Bldg, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6 (Canada); Forbes, Mark R., E-mail: mforbes6@gmail.com [Department of Biology, Carleton University, 209 Nesbitt Bldg, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6 (Canada); Hebert, Craig E., E-mail: Craig.Hebert@ec.gc.ca [Environment Canada, National Wildlife Research Centre, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1A 0H3 (Canada)

    2010-10-15

    Endoparasites can alter their host's heavy metal concentrations by sequestering metals in their own tissues. Contracaecum spp. (a nematode), but not Drepanocephalus spathans (a trematode), were bioaccumulating mercury to concentrations 1.5 times above cormorant hosts. Nematodes did not have significantly greater stable nitrogen isotope values ({delta}{sup 15}N) than their hosts, which is contradictory to prey-predator trophic enrichment studies, but is in agreement with other endoparasite-host relationships. However, Contracaecum spp. {delta}{sup 13}C values were significantly greater than their hosts, which suggest that nematodes were consuming host tissues. Nematodes were accumulating and thus sequestering some of their cormorant hosts' body burden of methyl mercury; however, they were not dramatically reducing their hosts' accumulation of methyl mercury.

  14. Trematod-inficeret reduktion i byssus produktion øger blåmuslingers (Mytilus edulis) mortalitet på grund af predation fra strandkrabber

    DEFF Research Database (Denmark)

    Karin Svane, Bech; Mouritsen, Kim Nørgaard

    fod, hvilket kan påvirke antallet af afsatte byssus tråde og dermed muslingens fasthæftningsstyrke. To feltforsøg i Limfjorden bekræftede, at infektion med H. elongata reducerer antallet af afsatte byssus tråde mens diameteren på trådene øges. Dette antyder, at muslingens evne til at producere byssus...... matrix ikke nedsættes betydeligt som følge af trematod infektionen men at reduktionen i antallet af byssus tråde måske skyldes en mekanisk funktionsfejl i foden. Det reducerede antal byssus tråde betyder, at inficerede muslingerne ikke er så sikkert fasthæftet til deres substrat og et forsøg viste...

  15. Effects of host species and life stage on the helminth communities of sympatric northern leopard frogs (Lithobates pipiens) and wood frogs (Lithobates sylvaticus) in the Sheyenne National Grasslands, North Dakota.

    Science.gov (United States)

    Gustafson, Kyle D; Newman, Robert A; Tkach, Vasyl V

    2013-08-01

    We studied helminth communities in sympatric populations of leopard frogs (Lithobates pipiens) and wood frogs (Lithobates sylvaticus) and assessed the effects of host species and life stage on helminth community composition and helminth species richness. We examined 328 amphibians including 218 northern leopard frogs and 110 wood frogs collected between April and August of 2009 and 2010 in the Sheyenne National Grasslands of southeastern North Dakota. Echinostomatid metacercariae were the most common helminths found, with the highest prevalence in metamorphic wood frogs. Host species significantly influenced helminth community composition, and host life stage significantly influenced the component community composition of leopard frogs. In these sympatric populations, leopard frogs were common hosts for adult trematodes whereas wood frogs exhibited a higher prevalence of nematodes with direct life cycles. Metamorphic frogs were commonly infected with echinostomatid metacercariae and other larval trematodes whereas juvenile and adult frogs were most-frequently infected with directly transmitted nematodes and trophically transmitted trematodes. Accordingly, helminth species richness increased with the developmental life stage of the host.

  16. [On the identification of the species Griphobilharzia amoena Platt, Blair, Purdie et Melville, 1991, a parasite of crocodiles in Australia].

    Science.gov (United States)

    Azimov, D A; Filimonova, L V; Shakabroev, É B; Akramova, F D

    2011-01-01

    The results of the study of typical specimens of the trematode G. amoena from blood vessels of the crocodile Crocodylus johnstoni in Australia are provided. The data obtained on the morphology of this parasite did not confirm the statement of Platt et al. (1991) that this species belongs to the family Schistosomatidae. Morphological data on G. amoena enable attributing it to the genus Vasotrema of the family Spirorchidae as a new species. In this connection, the monotypical genus Griphobilharzia (justified by Platt et al., 1991) becomes a synonym of the genus Vasotrema, while the subfamily Griphobilharziinae becomes a synonym of the subfamily Hapalotrematinae.

  17. Parasitic helminths in the digestive tract of six species of owls (Strigiformes) in Spain.

    Science.gov (United States)

    Ferrer, David; Molina, Rafael; Castellà, Joaquim; Kinsella, John M

    2004-03-01

    A survey was carried out in Catalonia, Spain to determine the prevalence of parasitic helminths infesting the digestive tract of nocturnal raptors (Strigiformes). One hundred birds belonging to six owl species were examined. The number of birds examined ranged between three and 30. The overall level of infestation was 65% and the most frequent helminths present were nematodes, followed by trematodes, cestodes and acanthocephalans. Strigiformes showing the highest levels of infestation were little owls (Athene noctua), 86.7% of which were infested. Helminths with the highest prevalence were Synhimantus spp., intestinal capillarids, Brachylaima spp., cestodes and Centrorhynchus aluconis.

  18. Euclinostomum heterostomum (Rudolphi, 1809 Metacercarial Infection in Three Osphronemid Fish Specieshree Osphronemid Fish Species

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    Watchariya PURIVIROJKUL

    2013-02-01

    Full Text Available Trematode metacercariae, Euclinostomum heterostomum from naturally infested osphronemid fish in Thailand were investigated. Encysted musculature was observed in the case of heavy infestation in all three osphronemid fish species, Trichopsis vittata, Betta splendens and Betta imbellis. Infected fish showed tubercle-like thickened areas of different size, 0.2 - 0.5 cm which appear on the skin. A histological study showed metacercaria were enclosed by a thin sheet of connective tissue. This is a new recorded host of E. heterostomum.

  19. Three new species of cercariae from Melanopsis praemorsa (L. 1758, Buccinum) snails in Al-Bathan fresh water body, Palestine

    Institute of Scientific and Technical Information of China (English)

    Sami Bdir; Ghaleb Adwan

    2012-01-01

    Objective: To investigate other new species of cercariae encountered in Melanopsis praemorsa (M. praemorsa) snails collected from Palestine. Methods: A total of 1 100 M. praemorsa were collected from Al-Bathan water body, Palestine, from November, 2010 to November, 2011. Cercariae in M. praemorsa were obtained by emerging and crushing methods. Results: Other three new different species of cercariae have been identified from this snail. These species were Xiphidiocercaria (Cercaria melanopsi palestinia IV), Microcercous (Cercaria melanopsi palestinia V) and Longifurcate cercaria (Cercaria melanopsi palestinia VI). The infection rate ofM. praemorsa with these three different cercariae was (42.2%). Coinfection with Xiphidiocercariae and Longifurcate cercariae or Xiphidiocercariae and Microcercous cercariae has been noted and coinfection rate was 1.23% among the infected snails. The highest cercarial infection rate was in June (64.3%). No infected snails were found in September. It was also noted that infected snails attained a larger size than uninfected ones and all infected snails had a size between 17-22 mm (average 20 mm). Conclusions: Our studies imply that there are potentially more new species of trematodes in this area than were found until now. Due to the presence of infected M. praemorsa and may be species of other snails, water resources could be contaminated by the emerging new cercariae, consequently attack the local people directly via the skin or are transferred to them by metacercariae ingestion. More surveys are needed to identify the real prevalence of the trematodes both in human and animal hosts, and also to determine the range of snail hosts of the parasite in enzootic areas of the disease, as well as the life cycle and biology of trematodes and its effects on man should be elucidated.

  20. The influence of trematodes on the macroalgae consumption by the common periwinkle Littorina littorea

    DEFF Research Database (Denmark)

    Clausen, Karin T.; Larsen, Martin H.; Iversen, Nina K.

    2008-01-01

    experiments offering the snails two different ephemeral green algae species as a food source. Our results show that, irrespective of the species of parasite and food source, infection decreases consumption: uninfected snails consumed up to 65% more macroalgal biomass than infected snails. Aside from infection...

  1. Phylogenetic relationships of some species of the family Echinostomatidae Odner, 1910 (Trematoda), inferred from nuclear rDNA sequences and karyological analysis.

    Science.gov (United States)

    Stanevičiūtė, Gražina; Stunžėnas, Virmantas; Petkevičiūtė, Romualda

    2015-01-01

    The family Echinostomatidae Looss, 1899 exhibits a substantial taxonomic diversity, morphological criteria adopted by different authors have resulted in its subdivision into an impressive number of subfamilies. The status of the subfamily Echinochasminae Odhner, 1910 was changed in various classifications. Genetic characteristics and phylogenetic analysis of four Echinostomatidae species - Echinochasmus sp., Echinochasmuscoaxatus Dietz, 1909, Stephanoprorapseudoechinata (Olsson, 1876) and Echinoparyphiummordwilkoi Skrjabin, 1915 were obtained to understand well enough the homogeneity of the Echinochasminae and phylogenetic relationships within the Echinostomatidae. Chromosome set and nuclear rDNA (ITS2 and 28S) sequences of parthenites of Echinochasmus sp. were studied. The karyotype of this species (2n=20, one pair of large bi-armed chromosomes and others are smaller-sized, mainly one-armed, chromosomes) differed from that previously described for two other representatives of the Echinochasminae, Echinochasmusbeleocephalus (von Linstow, 1893), 2n=14, and Episthmiumbursicola (Creplin, 1937), 2n=18. In phylogenetic trees based on ITS2 and 28S datasets, a well-supported subclade with Echinochasmus sp. and Stephanoprorapseudoechinata clustered with one well-supported clade together with Echinochasmusjaponicus Tanabe, 1926 (data only for 28S) and Echinochasmuscoaxatus. These results supported close phylogenetic relationships between Echinochasmus Dietz, 1909 and Stephanoprora Odhner, 1902. Phylogenetic analysis revealed a clear separation of related species of Echinostomatoidea restricted to prosobranch snails as first intermediate hosts, from other species of Echinostomatidae and Psilostomidae, developing in Lymnaeoidea snails as first intermediate hosts. According to the data based on rDNA phylogeny, it was supposed that evolution of parasitic flukes linked with first intermediate hosts. Digeneans parasitizing prosobranch snails showed higher dynamic of karyotype

  2. Life cycle of Renylaima capensis, a brachylaimid trematode of shrews and slugs in South Africa: two-host and three-host transmission modalities suggested by epizootiology and DNA sequencing

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    Sirgel Wilhelm F

    2012-08-01

    Full Text Available Abstract Background The life cycle of the brachylaimid trematode species Renylaima capensis, infecting the urinary system of the shrew Myosorex varius (Mammalia: Soricidae: Crocidosoricinae in the Hottentots Holland Nature Reserve, South Africa, has been elucidated by a study of its larval stages, epizootiological data in local snails and mammals during a 34-year period, and its verification with mtDNA sequencing. Methods Parasites obtained from dissected animals were mounted in microscope slides for the parasitological study and measured according to standardized methods. The mitochondrial DNA cox1 gene was sequenced by the dideoxy chain-termination method. Results The slugs Ariostralis nebulosa and Ariopelta capensis (Gastropoda: Arionidae act as specific first and second intermediate hosts, respectively. Branched sporocysts massively develop in A. nebulosa. Intrasporocystic mature cercariae show differentiated gonads, male terminal duct, ventral genital pore, and usually no tail, opposite to Brachylaimidae in which mature cercariae show a germinal primordium and small tail. Unencysted metacercariae, usually brevicaudate, infect the kidney of A. capensis and differ from mature cercariae by only a slightly greater size. The final microhabitats are the kidneys and ureters of the shrews, kidney pelvis and calyces in light infections and also kidney medulla and cortex in heavy infections. Sporocysts, cercariae, metacercariae and adults proved to belong to R. capensis by analysis of a 437-bp-long cox1 fragment, which was identical except for three mutations in metacercariae, of which only one silent. Epizootiological studies showed usual sporocyst infection in A. nebulosa and very rare metacercarial infection in A. capensis, which does not agree with high prevalences and intensities in the shrews. Conclusions The presence of monotesticular adult forms and larval prevalences and intensities observed suggest that R. capensis may use two transmission

  3. Prevalence and diversity of fish-borne zoonotic trematodes in tilapia (Oreochromis niloticus) culture in Guangdong, China

    DEFF Research Database (Denmark)

    Li, Kang; Murrell, Kenneth Darwin; Clausen, Jesper Hedegaard

    ), and Carassius auratus (4).The FZT species recovered were mainly Haplorchis taichui, and H. pumilio along with some unknown species whose identifications are still being determined. Subsequently a cross-sectional survey for the prevalence and diversity of FZT in tilapia culture systems was conducted in Guangdong...... Province during August-October 2011. A total of 389 tilapias sized 2.33-1450.00 g were collected from 30 farms, and examined for FZT metacercariae by the pepsin digestion method. Ten percent of the farms surveyed had fish with FZT infections. The overall FZT prevalence in fish was 1.5% and the infection...

  4. Local effects of a global problem: modelling the risk of parasite-induced mortality in an intertidal trematode-amphipod system.

    Science.gov (United States)

    Studer, A; Poulin, R; Tompkins, D M

    2013-08-01

    The interactive effects of climate change and parasitism are of concern because of potentially important consequences for host populations, communities and entire ecosystems. In marine environments, the absence of historic baseline data on parasitism and disease limits our ability to make realistic predictions about these consequences. Here, we adapt a simulation model developed for a Northern Hemisphere intertidal host-parasite system to a comparable system in the Southern Hemisphere. The entire life cycle of the intertidal trematode parasite Maritrema novaezealandensis was modelled in order to investigate the interactive effects of parasitic infections and increasing temperatures on the population dynamics of the amphipod host Paracalliope novizealandiae. Despite uncertainties associated with the model and its parameterisation, most temperature increases that were predicted to cause the collapse of the modelled amphipod population in the long term lay within the range of predicted warming for the study area. The high vulnerability of the amphipods in the modelled system illustrates a potentially important ecological mechanism by which consequences of a global problem might manifest on the local scale.

  5. Pathology and first occurrence of the kidney trematode Paratanaisia bragai (Santos, 1934 Freitas, 1959 (Digenea: Eucotylidae in Phasianus colchicus L., 1758, from Brazil

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    Delir Corrêa Gomes

    2005-05-01

    Full Text Available The kidney trematode Paratanaisia bragai is reported for the first time parasitizing the ring-necked pheasant (Phasianus colchicus L., 1758 and the pathological alterations associated to the parasitism are referred on the basis of 50 specimens of this bird from backyard flocks in 11 counties of the state of Rio de Janeiro, Brazil after clinical examination, necropsies, and histopathological analysis. The counting of the kidney flukes was based on worms recovered from one of the kidneys, since the other was fixed in 10% formalin and then routinely processed for histopathological procedures. The prevalence of P. bragai was of 22%, with a mean intensity of 44.3, mean abundance of 9.7, and range of infection of 3-153. Parasitized birds did not present with clinical signs and kidney gross lesions. Microscopic lesions were mild and characterized by dilatation of the renal medullary collecting ducts, occasional flattening of the lining epithelium of the ducts and inflammatory reaction of variable intensity with granulocytes around the ureter branches and medullary collecting ducts. The severity and pattern of the microscopic lesions seem not to be associated to the size of the worm burden and could be related to the mechanic action of the parasites, without traumatism, in despite of the presence of the tegumentar spines in specimens of P. bragai.

  6. Farm-level risk factors for fish-borne zoonotic trematode infection in integrated small-scale fish farms in northern Vietnam.

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    Van Thi Phan

    Full Text Available BACKGROUND: Northern Vietnam is an endemic region for fish-borne zoonotic trematodes (FZT, including liver and intestinal flukes. Humans acquire the FZT infection by eating raw or inadequately cooked fish. The production of FZT-free fish in aquaculture is a key component in establishing a sustainable program to prevent and control the FZT transmission to humans. Interventions in aquaculture should be based on knowledge of the main risk factors associated with FZT transmission. METHODOLOGY/PRINCIPAL FINDINGS: A longitudinal study was carried out from June 2006 to May 2007 in Nam Dinh province, Red River Delta to investigate the development and risk factors of FZT infections in freshwater cultured fish. A total of 3820 fish were sampled six times at two-month intervals from 96 fish farms. Logistic analysis with repeated measurements was used to evaluate potential risk factors based on information collected through questionnaire interviews with 61 fish farm owners. The results showed that the FZT infections significantly increased from first sampling in June to July 2006 (65% to sixth sampling in April to May, 2007 (76%. The liver fluke, Clonorchis sinensis and different zoonotic intestinal flukes including Haplochis pumilio, H. taichui, H. yokogawai, Centrocestus formosanus and Procerovum varium were found in sampled fish. Duration of fish cultured (sampling times, mebendazole drug self-medication of household members, presence of snails in the pond, and feeding fish with green vegetation collected outside fish farms all had a significant effect on the development of FZT prevalence in the fish. CONCLUSIONS/SIGNIFICANCE: The FZT prevalence in fish increased by 11 percentage points during a one-year culture period and the risk factors for the development of infection were identified. Results also highlight that the young fish are already highly infected when stocked into the grow-out systems. This knowledge should be incorporated into control

  7. Distribution and seasonal abundance of trematode parasites (Trematoda: Allocreadiidae: Crepidostomum spp.) in burrowing mayfly nymphs (Ephemeroptera: Ephemeridae: Hexagenia spp.) from connecting rivers of the Laurentian Great Lakes

    Science.gov (United States)

    Schloesser, Don W.

    2005-01-01

    Burrowing-mayfly nymphs such as Hexagenia spp. have been used extensively in North America and Europe as a biomonitoring tool to indicate mesotrophic water quality, yet infestation by associated parasites has not been well documented. We performed laboratory analysis of archived samples of Hexagenia spp. nymphs collected in 1985 and 1986 to provide base-line data on the distribution (1985) and seasonal infestation (1986) of the trematode parasite Crepidostomum spp. in Hexagenia spp. nymphs in connecting rivers between Lakes Superior and Erie of the Laurentian Great Lakes. In May and June 1985, frequency of occurrence of metacercariae was widely distributed throughout the connecting rivers (63% of 203 stations with nymphs), except in areas where nymph densities were relatively low (i.e.,a?Y69 nymphs/mA?). Distribution was probably underestimated in the present study because of low probability (mean = 31%, range = 0-57%) of detecting infestation in a small number of collected nymphs (a??10) at nymph densities a??69/mA?. In 1986, seasonal infestation between April and October occurred in 3.3% (627) of 18696 nymphs. Overall prevalence, mean intensity, and mean abundance of parasites at one station in the St. Marys River indicate parasite transmission occurred between June and September. This period of transmission is dependent on the life-cycle of the parasite. In addition, the life-cycle of Hexagenia spp. determines which annual cohort of nymphs is infested and therefore, the duration of infestation. Although, no impacts of infestation on Hexagenia spp. nymphs were observed in the present study, infestation intensities were high enough (a?Y25 metacercariae per nymph) at one station in the St. Marys River to potentially cause tissue damage in a high proportion (53%) of infested nymphs.

  8. 吸虫排泄分泌产物成分及其功能的研究进展%Research progress on the components and functions of excretory-secretory products of trematode

    Institute of Scientific and Technical Information of China (English)

    王利芳; 张锡林

    2010-01-01

    吸虫是一类重要的人兽共患寄生虫,不仅影响水产业和家畜业的生产,还严重威胁人类的健康.吸虫的排泄分泌产物(excretory-secretory products,ESP)在虫体致病机制中发挥重要的作用,研究其组成成分和相应的功能对探讨虫体和宿主的相互关系有重要的意义.目前已开展通过蛋白质组学和基因组学的相关技术对ESP的成分进行分离、提纯、重组表达,并在体内、外探讨各生物活性分子的生物活性和免疫调节功能的研究.该文就吸虫排泄分泌产物及功能的国内外研究进展作一综述.%Trematode is an important class of parasitic zoonosis not only affecting the production of aquaculture and livestock industry, but also seriously threatening human health. Excretory-secretory products (ESP) of trematode play an important role in the pathogenic mechanisms. Studying its composition and the corresponding function is of great significance for understanding the relationship between parasite and host. At present, using proteomics and genomics-related technology, many studies are involved in the purification/separation/re-expression of the ESP and the biological activity and immune function of the various elements in vivo or in vitro. In this paper, the research progress on the components and functions of ESP of trematode was reviewed.

  9. Development of functional genomic tools in trematodes: RNA interference and luciferase reporter gene activity in Fasciola hepatica.

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    Gabriel Rinaldi

    Full Text Available The growing availability of sequence information from diverse parasites through genomic and transcriptomic projects offer new opportunities for the identification of key mediators in the parasite-host interaction. Functional genomics approaches and methods for the manipulation of genes are essential tools for deciphering the roles of genes and to identify new intervention targets in parasites. Exciting advances in functional genomics for parasitic helminths are starting to occur, with transgene expression and RNA interference (RNAi reported in several species of nematodes, but the area is still in its infancy in flatworms, with reports in just three species. While advancing in model organisms, there is a need to rapidly extend these technologies to other parasites responsible for several chronic diseases of humans and cattle. In order to extend these approaches to less well studied parasitic worms, we developed a test method for the presence of a viable RNAi pathway by silencing the exogenous reporter gene, firefly luciferase (fLUC. We established the method in the human blood fluke Schistosoma mansoni and then confirmed its utility in the liver fluke Fasciola hepatica. We transformed newly excysted juveniles of F. hepatica by electroporation with mRNA of fLUC and three hours later were able to detect luciferase enzyme activity, concentrated mainly in the digestive ceca. Subsequently, we tested the presence of an active RNAi pathway in F. hepatica by knocking down the exogenous luciferase activity by introduction into the transformed parasites of double-stranded RNA (dsRNA specific for fLUC. In addition, we tested the RNAi pathway targeting an endogenous F. hepatica gene encoding leucine aminopeptidase (FhLAP, and observed a significant reduction in specific mRNA levels. In summary, these studies demonstrated the utility of RNAi targeting reporter fLUC as a reporter gene assay to establish the presence of an intact RNAi pathway in helminth

  10. Unusual snail species involved in the transmission of Fasciola hepatica in watercress beds in central France

    Directory of Open Access Journals (Sweden)

    Dreyfuss G.

    2002-06-01

    Full Text Available Four freshwater pulmonate species (Lymnaea ovata, L. stagnalis, Physa acuta, Planorbis leucostomawere living in several watercress beds known for their relationships with human cases of fasciolosis, whereas L. truncatula was never found. The aims of these studies were to determine the prevalence of natural infections with Fasciola hepatica in snails and to verify if these species might ensure the full larval development of this trematode (with cercarial shedding] when they were experimentally subjected to F. hepatica only, or to co-infections with an other trematode species. Investigations were so carried out in six snail populations living in watercress beds (including three for P. acuta and in four others originating from three brooks or a pond (as controls. Snails naturally infected with F. hepatica were found in two watercress beds inhabited by L. ovata (prevalence of infection: 1.4 % and P. leucostoma (0.1 %, respectively. The L. ovata from the watercress bed could be infected at a higher size than those from the control population and the prevalence of this infection was greater in the bed population. Similar findings were noted for L. stagnalis. Despite single or dual infections, the results obtained with the four populations of P. acuta were unsuccessful. In contrast, the co-infections of young P. leucostoma with Paramphistomum daubneyi and F. hepatica resulted in the shedding of some F. hepatica cercariae. According to the authors, the occurrence of fasciolosis in these watercress beds would be the consequence of frequent natural encounters between parasite and snails (L. ovata, L. stagnalis, or of co-infections with P. daubneyi and F. hepatica (P. leucostoma. In watercress beds only colonized by P. acuta, a lymnaeid species would have ensured the larval development of F. hepatica but it would have been eliminated by P. acuta, as this last species was known to be invasive and could colonize open drainage ditches on siliceous soil.

  11. Morphological and molecular differentiation of Parastrigea (Trematoda: Strigeidae) from Mexico, with the description of a new species.

    Science.gov (United States)

    Hernández-Mena, David Iván; García-Prieto, Luís; García-Varela, Martín

    2014-04-01

    Parastrigea plataleae n. sp. (Digenea: Strigeidae) is described from the intestine of the roseate spoonbill Platalea ajaja (Threskiornithidae) from four localities on the Pacific coast of Mexico. The new species is mainly distinguished from the other 18 described species of Parastrigea based on the ratio of its hindbody length to forebody length. A principal component analysis (PCA) of 16 morphometric traits for 15 specimens of P. plataleae n. sp., five of Parastrigea cincta and 11 of Parastrigea diovadena previously recorded in Mexico, clearly shows three clusters, which correspond to the three species. DNA sequences of the internal transcribed spacers (ITSs) of ribosomal DNA and the mitochondrial gene cytochrome c oxidase subunit I (cox 1) were used to corroborate this morphological distinction. The genetic divergence estimated among P. plataleae n. sp., P. cincta and P. diovadena ranged from 0.5 to 1.48% for ITSs and from 9.31 to 11.47% for cox 1. Maximum parsimony (MP) and maximum likelihood (ML) analyses were performed on the combined datasets (ITSs+cox 1) and on each dataset alone. All of the phylogenetic analyses indicated that the specimens from the roseate spoonbill represent a clade with strong bootstrap support. The morphological evidence and the genetic divergence in combination with the reciprocal monophyly in all of the phylogenetic trees support the hypothesis that the digeneans found in the intestines of roseate spoonbills represent a new species.

  12. The Pampulha reservoir remains a potential urban focus of schistosomiasis mansoni in Brazil: changes in the occurrence patterns of Biomphalaria species and a new record of the parasite

    Directory of Open Access Journals (Sweden)

    Hudson Alves Pinto

    2013-08-01

    Full Text Available Introduction The Pampulha reservoir has long been a focus of schistosomiasis transmission in Belo Horizonte, State of Minas Gerais, Brazil. The last malacological study conducted in this urban reservoir was more than two decades ago, and thus, an update on the distribution of the species of Biomphalaria as well as new data on the presence of Schistosoma mansoni in this water body are required. Methods The current distribution of Biomphalaria spp. in the Pampulha reservoir and their infection with S. mansoni was evaluated during 55 malacological surveys conducted between 2009 and 2012. Results Biomphalaria straminea displayed a high population density and distribution, and 13.7% (2,233/16,235 of the specimens collected were infected with larval trematodes other than Schistosoma mansoni. Biomphalaria tenagophila and Biomphalaria glabrata, species currently presenting a restricted distribution and small populations, displayed trematode infection rates of 15.2% (98/644 and 13% (83/640, respectively. Thirteen (2% specimens of B. glabrata were found to be infected with S. mansoni. In addition, a historical review based on previous and new data on the occurrence patterns of Biomphalaria species in this reservoir is presented. Conclusions The results indicate that the Pampulha reservoir remains a potential focus of urban schistosomiasis in Brazil, and significant changes in the occurrence patterns of Biomphalaria species were verified.

  13. Plagiorchis Muris (Tanabe, 1922 in Rattus Norvegicus in Iran

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    Gholamreza Mowlavi

    2013-09-01

    Full Text Available Rats are capable to harbor various pathogens, among which certain species of zoonotic parasites are included. A long-term detection of parasite fauna of rats has sporadically been carried out in Iran. Abundance of these vertebrate pests is of great importance as regards public health issue. The present paper is fo­cused on a digenean trematode Plagiorchis muris, obtained during a comprehensive study on rats over the decades in the country. Herein we describe this occurrence in a Rattus norvegicus in northern Tehran, with specific note on its morphological description. P. muris can infect human through consumption of infected marine food items, and has never been observed in Iran.

  14. Helminth parasites of eastern box turtles (Terrapene carolina carolina) from southern Indiana, USA.

    Science.gov (United States)

    Moraga, P; Kinsella, J M; Sepúlveda, M S

    2012-03-01

    Very little is known about parasitic diseases of eastern box turtles (Terrapene carolina carolina). The objective of this study was to examine the parasitic fauna of eastern box turtles collected from southern Indiana, USA. Turtles (n = 40) were salvaged mostly as road kills from southern Indiana between May and October 2009. Seven species of helminths in total were found parasitizing the gastrointestinal tract, including two digenean trematodes (Brachycoelium salamandrae and Telorchis robustus) and five nematodes (Oswaldocruzia pipiens, Cosmocercoides dukae, Falcaustra affinis, F. chelydrae and Serpinema trispinosus). We report prevalence, abundance and mean intensity of infection for all helminths. Helminths were not found in any other organs examined (heart, gonads, liver, heart, kidney and urinary bladder) and no ectoparasites were found. Overall, mean intensity of infections was low (1-14 parasites/host), suggesting that these parasites are unlikely to be associated with negative health impacts. This constitutes the first study of this kind for Indiana.

  15. Euclinostomum heterostomum infection in guppies Poecilia reticulata cultured in Southern Thailand.

    Science.gov (United States)

    Suanyuk, Naraid; Mankhakhet, Suchanya; Soliman, Hatem; Saleh, Mona; El-Matbouli, Mansour

    2013-05-27

    During April to June 2009 and February 2010 to February 2011, numerous digenetic trematode metacercariae were observed embedded in the muscles of guppies Poecilia reticulata cultured at Kidchakan Supamattaya Aquatic Animal Health Research Center, Songkhla, southern Thailand. A total of 424 guppies were examined to identify the parasite and to study its pathogenicity. Based on conventional parasitological techniques, the parasitic digenean found in the guppies was identified as Euclinostomum heterostomum Rudolphi, 1809. Histological analysis revealed numerous metacercariae embedded in the fish muscle. A life cycle study indicated that the snail Indoplanorbis exustus was the first intermediate host, with the guppies serving as the second intermediate host. No E. heterostomum metacercariae were found in cohabited fish species, giant sailfin molly Poecilia velifera or platy Xiphophorus maculatus, which indicated that the guppy was the only suitable fish host present.

  16. Species concepts and species delimitation.

    Science.gov (United States)

    De Queiroz, Kevin

    2007-12-01

    The issue of species delimitation has long been confused with that of species conceptualization, leading to a half century of controversy concerning both the definition of the species category and methods for inferring the boundaries and numbers of species. Alternative species concepts agree in treating existence as a separately evolving metapopulation lineage as the primary defining property of the species category, but they disagree in adopting different properties acquired by lineages during the course of divergence (e.g., intrinsic reproductive isolation, diagnosability, monophyly) as secondary defining properties (secondary species criteria). A unified species concept can be achieved by treating existence as a separately evolving metapopulation lineage as the only necessary property of species and the former secondary species criteria as different lines of evidence (operational criteria) relevant to assessing lineage separation. This unified concept of species has several consequences for species delimitation, including the following: First, the issues of species conceptualization and species delimitation are clearly separated; the former secondary species criteria are no longer considered relevant to species conceptualization but only to species delimitation. Second, all of the properties formerly treated as secondary species criteria are relevant to species delimitation to the extent that they provide evidence of lineage separation. Third, the presence of any one of the properties (if appropriately interpreted) is evidence for the existence of a species, though more properties and thus more lines of evidence are associated with a higher degree of corroboration. Fourth, and perhaps most significantly, a unified species concept shifts emphasis away from the traditional species criteria, encouraging biologists to develop new methods of species delimitation that are not tied to those properties.

  17. Invasive Species

    Science.gov (United States)

    Invasive species have significantly changed the Great Lakes ecosystem. An invasive species is a plant or animal that is not native to an ecosystem, and whose introduction is likely to cause economic, human health, or environmental damage.

  18. New records of rare derogenids (Digenea: Hemiuroidea) from Mediterranean sparids, including the description of a new species of Magnibursatus Naidenova, 1969 and redescription of Derogenes adriaticus Nikolaeva, 1966.

    Science.gov (United States)

    Kostadinova, Aneta; Gibson, David I

    2009-11-01

    Records of derogenid digeneans in the Mediterranean and Black Sea region are scarce and tend to be restricted to a small number of host-groups, but especially to sparid fishes. This work reports on the presence of derogenine and halipegine derogenids from two sparids, Diplodus annularis (L.) and D. sargus (L.), from off the Mediterranean coast of Spain. Five derogenid forms were recovered. Derogenes adriaticus Nikolaeva, 1966 is redescribed from Diplodus annularis, and Derogenes sp. is described from the same host but differentiated from the former species. Magnibursatus barretti n. sp. is described from Diplodus sargus and distinguished from other species of the genus especially by its smaller body size and smaller eggs. M. bartolii Kostadinova, Power, Fernández, Balbuena, Raga & Gibson, 2003 is redescribed from D. sargus, a new host for this species. A single specimen from D. sargus, somewhat similar to M. minutus Kostadinova, Power, Fernández, Balbuena, Raga & Gibson, 2003, is also described, as it exhibits some morphometric differences from the latter species.

  19. Alguns trematódeos monogenéticos da família Capsalidae Baird, 1853, em peixes do Oceano Atlântico - Costa Continental Portuguesa e Costa do Norte da África Some monogenetic trematodes of Portuguese Continental Cost and North African Cost

    Directory of Open Access Journals (Sweden)

    Ursula Buhrnheim

    1973-01-01

    Full Text Available No presente trabalho é feito um estudo de cinco trematódeos monogenéticos pertencentes à família Capsalidae Baird, 1853. Para a subfamília Benedeniinae Johnston, 1931, foram criadas duas espécies pertencenteso ao gênero Benedenia Diesing, 1858: Benedenia pompatica sp. n., que muito se assemelha a Benedenia sciaenae (Beneden, 1852, diferindo desta principalmente pela estrutura do 2º e 3º pares de macroganchos e Benedenia innobilitata sp. n. que mais se aproxima de Benedenia jaliscana Bravo-Hollis, 1951, afastando-se desta espécie pela ausência do cirro armado e também pela estrutura e localização da vagina. Da subfamília Trochopodiane (Price, 1936 são apresentados novos hospedadores: Lepidotrigla cavillone para Trochopus pini (Beneden & Hesse, 1863 e Serranus cabrilla para Megalocotyle grandiloba Paperna e Kohn, 1964, sendo apresentadas com novas descrições e ilustrações. Ainda desta subfamília é criada uma nova espécie do gênero Allomegalocotyle (Robinson, 1961 Yamaguti, 1963. A. gabbari sp. n. diferencia-se de A. johnstoni (Robinson, 1961, única espécie do gênero, pela morfologia dos macroganchos, localização do poro vaginal e vesícula seminal bem desenvolvida e externa.In this paper we make a study of five monogenetic trematodes of the family Capsalidae Baird, 1853. We describe two new species of the genus Benedenia Diesing, 1858, Benedeniinae Johnston, 1931: Benedenia pompatica sp. n., which is very similar to Benedenia sciaenae (Beneden, 1852 abd differs from it mainly by the structure of the second and third pair of the haptoral hooks; and Benedenia innobilitata sp. n. near to Benedenia jaliscana Bravo-Hollis, 1951 does not have the armed cirrus, proper to the last and the structure and position of the vagina is also a considered characteristic. For the subfamily Trochopodinae (Price, 1936 we give new hosts: Lepidotrigla cavillone for Trochopus pini (Beneden & Hesse, 1863 and Serranus cabrilla for Megalocotyle

  20. First record of a rare transversotrematid cercaria larva (Trematoda: Digenea) from Rajasthan, India: focus on seasonal occurrence and host-specificity of diverse cercariae.

    Science.gov (United States)

    Choubisa, Shanti Lal; Jaroli, Vishva Jeet; Sheikh, Zulfiya

    2017-06-01

    During the survey of freshwater snail hosts and their digenean larval trematode parasites, a rare cercaria larva belonging to family Transversotrematidae and subclass Digenea (Trematoda) was recovered from the snail species Melanoides striatella tuberculata inhabiting perennial Som river of Udaipur district, Rajasthan, India. More than 28 % mature specimens of these snails were found to be infected with transversotrematid cercaria larvae in the spring season. Body of this cercaria is large, bowl-shaped, biocellate, spinose, transparent and laterally extended having two pigmented eye spots, two hold fast organs extended from the junction of body and tail, large tail with two foliated furcal rami, and cyclocoel intestinal caeca. As far as the authors are aware, this is the first record of a transversotrematid larva from Rajasthan, India. Simultaneously, other forms of cercariae viz., amphistome, echinostome, monostome, gymnocephalous, furcocercous and xiphidiocercous cercariae were also recovered from fifteen species of pulmonate and operculate snails including Lymnaea acuminata f. patula, L. acuminata f. chlamys, L. acuminata f. typica, L. acuminata f. rufescens, L. luteola f. australis, L. luteola f. typica, L. luteola f. impura, Planorbis (Indoplanorbis) exustus, and Anisus (Gyraulus) convexiusculus, Faunus ater, Melania (Plotia) scabra, Thiara (Tarebia) lineata, Melanoides striatella tuberculata, Vivipara bengalensis race gigantica and V. bengalensis race mandiensis. The seasonal occurrence and host-specificity of diverse trematode cercaria larvae are also discussed besides the first record of a rare transversotrematid cercaria larva from Rajasthan, India.

  1. Differential precocious sexual development of Proctoeces lintoni (Digenea: Fellodistomidae) in three sympatric species of keyhole limpets Fissurella spp. may affect transmission to the final host.

    Science.gov (United States)

    Balboa, L; George-Nascimento, M; Ojeda, F P

    2001-10-01

    The prevalence, abundance, and developmental status of the digenetic trematode Proctoeces lintoni Siddiqui et Cable 1960 were compared in 3 species of keyhole limpets Fissurella. A total of 197 limpets was collected at Caleta Chome, south-central Chile. Fissurella picta and F. costata had the highest prevalence of infection, whereas F. picta showed the greatest abundance of parasites, which increased with host shell length. However, the frequency of P. lintoni specimens with eggs in the uterus was greatest in F. costata. These results suggest that an increased rate of development of a parasite in the intermediate host may shorten the residence time necessary for maturation in the final host. Thus, faster development of the parasite in F. costata suggests the possibility that the parasites transmitted through this host species have shorter maturation times in clingfishes than individuals transmitted via other limpet species.

  2. The genus lobatostoma (Trematoda: Aspidocotylea in the pacific coast of South America, with description of Lobatostoma veranoi new species, parasite of Menticirrhus ophycephalus (Teleostei: Sciaenidae

    Directory of Open Access Journals (Sweden)

    Marcelo E. Oliva

    1989-06-01

    Full Text Available The presence of three aspidocotyleans trematodes in marine fishes from Perú and Chile is reported. One of them, Lobatostoma veranoi from the intestine of Menticirrhus ophicephalu (Sciaenidae is considered a new species. Distinct characteristcs of the new species are:a cirrus sac smaller than the pharynx; tail overlapping posteriorly the ventral disk; testis in the last third of the body and the presence of 64-66 marginal alveoli. The two other species are Lobatostoma pacificum Manter, 1940 found in Trachinotus paitensis Cuvier, 1830 from Perú and Chile and Lobatostoma Anisotremum Oliva & Carvajal, 1984 from the intestine of Anisotremus scapularis (Tschudi, 1844 from Perú.

  3. An integrated pipeline for next generation sequencing and annotation of the complete mitochondrial genome of the giant intestinal fluke, Fasciolopsis buski (Lankester, 1857) Looss, 1899.

    Science.gov (United States)

    Biswal, Devendra Kumar; Ghatani, Sudeep; Shylla, Jollin A; Sahu, Ranjana; Mullapudi, Nandita; Bhattacharya, Alok; Tandon, Veena

    2013-01-01

    Helminths include both parasitic nematodes (roundworms) and platyhelminths (trematode and cestode flatworms) that are abundant, and are of clinical importance. The genetic characterization of parasitic flatworms using advanced molecular tools is central to the diagnosis and control of infections. Although the nuclear genome houses suitable genetic markers (e.g., in ribosomal (r) DNA) for species identification and molecular characterization, the mitochondrial (mt) genome consistently provides a rich source of novel markers for informative systematics and epidemiological studies. In the last decade, there have been some important advances in mtDNA genomics of helminths, especially lung flukes, liver flukes and intestinal flukes. Fasciolopsis buski, often called the giant intestinal fluke, is one of the largest digenean trematodes infecting humans and found primarily in Asia, in particular the Indian subcontinent. Next-generation sequencing (NGS) technologies now provide opportunities for high throughput sequencing, assembly and annotation within a short span of time. Herein, we describe a high-throughput sequencing and bioinformatics pipeline for mt genomics for F. buski that emphasizes the utility of short read NGS platforms such as Ion Torrent and Illumina in successfully sequencing and assembling the mt genome using innovative approaches for PCR primer design as well as assembly. We took advantage of our NGS whole genome sequence data (unpublished so far) for F. buski and its comparison with available data for the Fasciola hepatica mtDNA as the reference genome for design of precise and specific primers for amplification of mt genome sequences from F. buski. A long-range PCR was carried out to create an NGS library enriched in mt DNA sequences. Two different NGS platforms were employed for complete sequencing, assembly and annotation of the F. buski mt genome. The complete mt genome sequences of the intestinal fluke comprise 14,118 bp and is thus the shortest

  4. An integrated pipeline for next generation sequencing and annotation of the complete mitochondrial genome of the giant intestinal fluke, Fasciolopsis buski (Lankester, 1857 Looss, 1899

    Directory of Open Access Journals (Sweden)

    Devendra Kumar Biswal

    2013-11-01

    Full Text Available Helminths include both parasitic nematodes (roundworms and platyhelminths (trematode and cestode flatworms that are abundant, and are of clinical importance. The genetic characterization of parasitic flatworms using advanced molecular tools is central to the diagnosis and control of infections. Although the nuclear genome houses suitable genetic markers (e.g., in ribosomal (r DNA for species identification and molecular characterization, the mitochondrial (mt genome consistently provides a rich source of novel markers for informative systematics and epidemiological studies. In the last decade, there have been some important advances in mtDNA genomics of helminths, especially lung flukes, liver flukes and intestinal flukes. Fasciolopsis buski, often called the giant intestinal fluke, is one of the largest digenean trematodes infecting humans and found primarily in Asia, in particular the Indian subcontinent. Next-generation sequencing (NGS technologies now provide opportunities for high throughput sequencing, assembly and annotation within a short span of time. Herein, we describe a high-throughput sequencing and bioinformatics pipeline for mt genomics for F. buski that emphasizes the utility of short read NGS platforms such as Ion Torrent and Illumina in successfully sequencing and assembling the mt genome using innovative approaches for PCR primer design as well as assembly. We took advantage of our NGS whole genome sequence data (unpublished so far for F. buski and its comparison with available data for the Fasciola hepatica mtDNA as the reference genome for design of precise and specific primers for amplification of mt genome sequences from F. buski. A long-range PCR was carried out to create an NGS library enriched in mt DNA sequences. Two different NGS platforms were employed for complete sequencing, assembly and annotation of the F. buski mt genome. The complete mt genome sequences of the intestinal fluke comprise 14,118 bp and is thus the

  5. Ciliary activity of cells of gill and leg glimmeral epithelium of Unionidae invaded by trematodes of Aspidogaster conchicola and Bucephalus polymorphus

    National Research Council Canada - National Science Library

    Chernomaz, T V

    2001-01-01

    The paper provides data concerning the influence of the parasitic worms Aspidogaster conchicola and Bucephalus polymorphus on the rate and duration of ciliary beating of gill and leg in 7 species of Unionidae...

  6. Invasive species

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a summary of management activities and research related to invasive species on Neal Smith National Wildlife Refuge between 1992 and 2009. As part of the...

  7. Spatiotemporal distributions of intestinal helminths in female lesser scaup Aythya affinis during spring migration from the upper Midwest, USA

    Science.gov (United States)

    England, J. C.; Levengood, J.M.; Osborn, J. M.; Yetter, A. P.; Kinsella, J.M.; Cole, Rebecca A.; Cory D. Suski,; Hagy, Heath M.

    2016-01-01

    We examined the associations between intestinal helminth infracommunity structure and infection parameters and the age, size, and year and region of collection of 130 female lesser scaup (Aythya affinis) during their 2014–2015 spring migrations through the upper Midwest, USA. We identified a total of 647,174 individual helminths from 40 taxa, including 20 trematodes, 14 cestodes, 4 nematodes and 2 acanthocephalans parasitizing lesser scaup within the study area. Lesser scaup were each infected with 2–23 helminth taxa. One digenean, Plenosoma minimum, is reported for the first time in lesser scaup and in the Midwest. Mean trematode abundance and total helminth abundance was significantly less in 2015 than 2014, and we suspect that colder weather late in 2015 impacted the intermediate host fauna and caused the observed differences. Brillouin's species diversity of helminths was greatest in the northernmost region of the study area, which coincides with the range of a non-indigenous snail that indirectly causes annual mortality events of lesser scaup. While host age and size were not determined to be influential factors of helminth infracommunity structure, non-parametric ordination and permutational analysis of co-variance revealed that year and region of collection explained differences in helminth infracommunities. Our results suggest that spatiotemporal variations play an important role in the structure of intestinal helminth infracommunities found in migrating lesser scaup hosts, and may therefore impact host ability to build endogenous reserves at certain stopover locations in the Midwest.

  8. Seasonal dynamics of the cercarial and metacercarial stages of the microphallid trematode Maritrema eroliae(Digenea: Microphallidae)%滨鹬马蹄吸虫(复殖目:微茎科)的尾蚴和囊蚴期的季节动态

    Institute of Scientific and Technical Information of China (English)

    M. A. AL-KANDARI; J. M. ABDUL-SALAM; M. A. MOUSSA; B. S. SREELATHA

    2007-01-01

    对科威特湾微茎科滨鹬马蹄吸虫幼虫期的中间宿主双带盾桑椹螺(Clypeomorus bifasciata)及小相手蟹(Nanosesarma minutum)的季节动态进行了研究.调查期超过一年,在检查的1 600只螺和415只蟹中,11.8%的螺感染了8种马蹄属线虫中的一种,且以滨鹬马蹄吸虫的感染占优势(9.9%螺感染);80%的蟹感染滨鹬马蹄吸虫囊蚴.虽然一年四季两种宿主都会感染,但吸虫的流行和尾蚴(指成熟期感染)在夏季呈现高蜂.从螺体排出的尾蚴具有明显季节性,在此海湾必须要超过最低温度20℃.总的感染率在较大(较老)的螺里有所下降,显示吸虫影响宿主生存并随之影响宿主群体结构.囊蚴的感染丰度与蟹的个体大小有明显相关性;较大的蟹感染较多的囊蚴,显示宿主能耐受更多的吸虫.调查显示,囊蚴的感染率与蟹的大小或性别无相关性.囊蚴体外脱囊以及产卵吸虫的释放证明,成熟虫体终年存在于所有大小和性别不同的蟹里,显示从蟹到鸟的持续感染是可能的.总的来说,滨鹬马蹄吸虫在海湾的传播动态是由这两种无脊椎动物宿主来协调,并似乎是被一系列依赖于温度的活动控制,这些活动影响易感宿主种群及感染性幼虫期尾蚴和囊蚴的存在[动物学报 53(3):463-469,2007].%The seasonal dynamics of larval stages of the microphallid trematode Maritrema eroliae Yamaguti, 1939 in intermediate hosts, the prosobranch snail Clypeomorus bifasciata(Sowerby, 1855)and the brachyuran crab Nanosesarma minutum(de Man, 1887), in Kuwait Bay was examined. Over a one-year period,1 600 snails and 415 crabs were collected and examined for larval trematodes, 11.8% of snails were infected with one of 8 species dominated by M.eroliae(9.9%), and 80% of crabs harbored M.eroliae metacercariae. Although infections persisted in both host species throughout the year, significant summer peaks were recorded in parasite prevalence and cercarial

  9. Molecular characterization of cryptic and sympatric lymnaeid species from the Galba/Fossaria group in Mendoza Province, Northern Patagonia, Argentina

    Science.gov (United States)

    2013-01-01

    Background Freshwater lymnaeid snails can act as the intermediate hosts for trematode parasites such as the liver fluke Fasciola hepatica, that cause significant economic and biomedical burden worldwide, particularly through bovine fascioliasis. Transmission potential is tightly coupled to local compatibility with snail hosts, so accurate identification of lymnaeid species is crucial for understanding disease risk, especially when invasive species are encountered. Mendoza Province, in Argentina, is a center of livestock production and also an area of endemic fascioliasis transmission. However, the distribution of lymnaeid species in the region is not well known. Methods This study examined lymnaeid snails from seven localities in the Department of Malarguë, Mendoza Province, using morphological and molecular analyses and also describing ecological variables associated with snail presence. Results While morphological characters identified two species of lymnaeid, Galba truncatula and G. viatrix, molecular data revealed a third, cryptic species, G. neotropica, which was sympatric with G. viatrix. G. truncatula was exclusively found in high altitude (>1900 meters above sea level [masl]) sites, whereas mixed G. neotropica/G. viatrix localities were at middle elevations (1300–1900 masl), and G. viatrix was found alone at the lowest altitude sites (variables while avoiding nomenclature redundancy. As the three species observed here, including one alien invasive species, are considered hosts of varying susceptibility to Fasciola parasites, and given the economic importance of fascioliasis for livestock production, this research has critical importance for the ultimate aim of controlling disease transmission. PMID:24499569

  10. Establishment and interspecific associations in two species of Ichthyocotylurus (Trematoda parasites in perch (Perca fluviatilis

    Directory of Open Access Journals (Sweden)

    Karvonen Anssi

    2011-05-01

    Full Text Available Abstract Background Co-infections of multiple parasite species in hosts may lead to interspecific associations and subsequently shape the structure of a parasite community. However, few studies have focused on these associations in highly abundant parasite species or, in particular, investigated how the associations develop with time in hosts exposed to co-infecting parasite species for the first time. We investigated metacercarial establishment and interspecific associations in the trematodes Ichthyocotylurus variegatus and I. pileatus co-infecting three age cohorts of young perch (Perca fluviatilis. Results We found that the timing of transmission of the two Ichthyocotylurus species was very similar, but they showed differences in metacercarial development essentially so that the metacercariae of I. pileatus became encapsulated faster. Correlations between the abundances of the species were significantly positive after the first summer of host life and also within the main site of infection, the swim bladder. High or low abundances of both parasite species were also more frequent in the same host individuals than expected by chance, independently of host age or size. However, the highest abundances of the species were nevertheless observed in different host individuals and this pattern was consistent in all age cohorts. Conclusions The results suggest similar temporal patterns of transmission, non-random establishment, and facilitative rather than competitive associations between the parasite species independently of the age of the infracommunities. However, we suggest that spatial differences in exposure are most likely responsible for the segregation of the parasite species observed in the few most heavily infected hosts. Regardless of the underlying mechanism, the result suggests that between-species associations should be interpreted with caution along with detailed examination of the parasite distribution among host individuals.

  11. Biogeography of tropical Indo-West Pacific parasites: a cryptic species of Transversotrema and evidence for rarity of Transversotrematidae (Trematoda) in French Polynesia.

    Science.gov (United States)

    Cribb, Thomas H; Adlard, Robert D; Bray, Rodney A; Sasal, Pierre; Cutmore, Scott C

    2014-04-01

    We sought transversotrematid trematodes from French Polynesian fishes by examining 304 individual scaled fishes of 53 species from seven families known to harbour the family elsewhere. A single species was found at two locations in the Tuamotus Archipelago on two species of Chaetodontidae (Chaetodon auriga and Chaetodon ephippium) and one species of Lutjanidae (Lutjanus gibbus). The species closely resembles Transversotrema borboleta Hunter & Cribb, 2012 from chaetodontids and lutjanids of the northern Great Barrier Reef (GBR) but differs from it consistently in 8 base positions of ITS2 rDNA. This level of variation exceeds that between some clearly morphologically distinct pairs of species of Transversotrema and the form from French Polynesia is thus interpreted as a distinct, though cryptic, species and named Transversotrema polynesiae n. sp. The new species forms part of a complex of species, here characterised as the T. borboleta complex, associated with chaetodontids and lutjanids in the tropical Indo-West Pacific. Most of the putative species within this complex are yet to be described. Comparison of identical numbers of matched samples of fishes from French Polynesia, Heron Island (southern GBR) and Lizard Island (northern GBR) revealed 1, 4 and 10 species of Transversotrema respectively suggesting that the French Polynesian fauna is depauperate for this family. In addition to those species apparently missing from suitable hosts in French Polynesia, several species from further west infect fishes (especially Nemipteridae) that are themselves absent from French Polynesia. This dramatic east-west decline in richness contrasts strongly with what is known for monogeneans, which appear to maintain their richness over the same scale, and is more precipitate than is known for other groups of trematodes. The decline might be explained in part by the absence of the as yet unknown first intermediate hosts in French Polynesia. However, we predict that it is explained

  12. Effect of pond water depth on snail populations and fish-borne zoonotic trematode transmission in juvenile giant gourami (Osphronemus goramy) aquaculture nurseries

    DEFF Research Database (Denmark)

    Thien, P. C.; Madsen, Henry; Nga, H. T. N.

    2015-01-01

    as first intermediate host and a variety of fish species, both wild caught and cultured, as second intermediate host. Aquaculture production has grown almost exponentially in SE Asia and in order to produce fish free from FZT metacercariae, it is important to mitigate factors promoting transmission to fish...

  13. The life-cycle of the digenetic trematode, Proctoeces maculatus (Looss, 1901) Odhner, 1911 (Syn. P. rubtenuis [Linton, 1907] Hanson, 1950), and description of Cerceria adranocerca n. sp

    Science.gov (United States)

    Stunkard, H.W.; Uzmann, J.R.

    1959-01-01

    The genus Proctoeces was erected by Odhner ( 191 1) to contain Distonium maculatuni Looss, 1901, from Labrus merula and Crenilabrus spp. at Triest. Odhner had found the parasite in Blennius ocellaris at Naples. One adult specimen from Chrysophrys bifasciata and two immature specimens from lulis lunaris taken in the Red Sea, were described as a new species, Proctoeces erythraeus. Dawes (1946) listed P. erythraeus as a synonym of  P. maculatus (Looss) , but the species was recognized by Manter ( 1947) on the basis of six specimens he had collected from Calamus calamus and Calamus bajonado at the biological laboratory of the Carnegie Institution at Dry Tortugas, Florida. Several additional species have been de scribed. Fujita ( 1925) reported a metacercaria from the Japanese oyster, Ostrea gigas, as a new species, Proctoeces ostreae. The paper was translated by R. Ph. Dollfus who noted (p. 57) ,“Il est à souhaiter que des recherches chez les poissons mangers de Lamellibranches, sur les côtes de la préfecture d'Hiroshima, permettent de découvrir des exemplaires complètement adultes de Proctoeces ostreae Fuj., chez lesquels l'extension des vitellogènes et les dimensions des oeufs puissent être observées avec précision; il sera alors possible de savoir définitivement si P. ostreae Fuj. doit ou non tomber en synonymie avec P. maculatus (Looss)." Yamaguti (1934) described P. maculatus from Sparus aries, Sparws macrocephalus, Pagrosomus auratus, and Epinephelus akaara in Japan. Several specimens from Pagrosomus auratus, which differed from P. maculatus in larger size, larger eggs, and trilobed ovary, he described as a new species, Proctoeces major. Yamaguti ( 1938) reported P. nzaculatus from Sensicossyphus reticulatus and described a larva from the liver of the pelecypod mollusk, Brachidontes senhausi, as an unidentified member of the genus Proctoeces. Manter ( 1940) described Proctoeces tnagnorus from a single specimen found in the intestine of Caulolatilus

  14. 广东海产鱼类两种复殖吸虫包括一新种的记述%TWO DIGENETIC TREMATODES OF GUANGDONG MARINE FISHES WITH THE DESCRIPTION OF A NEW SPECIES

    Institute of Scientific and Technical Information of China (English)

    吴小明

    2000-01-01

    本文记述发现于广东阳江黄斑蓝子鱼肠道的广东寡腺吸虫,新种Oligolecithoides guangdongensis sp.nov.及日本金线鱼肠道的中长单肠吸虫Monascus medisolongiusculus Ding, 1993.新种前列腺膨大呈囊状,肠前部不膨大成结,食道短,体形梭形等特征与已知种明显不同.日本金线鱼为中长单肠吸虫Monascus mediolongiusculus Ding, 1993宿主新记录.

  15. Plagiorchis vicentei. sp.n. (Trematoda, Plagiorchiidae a new trematode from Hemidactylus mabouia (Moreau de Jonnès (Lacertilia, Gekkonidae

    Directory of Open Access Journals (Sweden)

    Henrique de Oliveira Rodrigues

    1994-01-01

    Full Text Available Plagiorchis vicentei, sp.n. is described from the small intestine of the lizard, Hemidactylus mabouia (Moreau de Jonnès, 1818, from Teresópolis, Rio de Janeiro, Brasil. The new species differs from P. didelphidis (Parona, 1896 by the smaller size of body, by the presence of spinous tegument and ventral sucker smaller than oral sucker; from P. parumbursaitus Freitas & Dobbin Jr., 1961 by the smaller size of body and suckers and the bigger size of eggs; from P. rangeli Artigas & Zerpa, 1961 by the bigger size of suckers and eggs; and front P. freitasi Vicente, 1978 by the smaller size of body, by the bigger size of eggs and by the different position of gonads that in the new species are close to the ventral sucker.

  16. A complex of species related to Paradiscogaster glebulae (Digenea: Faustulidae) in chaetodontid fishes (Teleostei: Perciformes) of the Great Barrier Reef.

    Science.gov (United States)

    Diaz, Pablo E; Bray, Rodney A; Cutmore, Scott C; Ward, Selina; Cribb, Thomas H

    2015-10-01

    A total of 1523 individuals of 34 species of chaetodontids from the Great Barrier Reef were examined for faustulid trematodes. Specimens resembling Paradiscogaster glebulae Bray, Cribb & Barker, 1994 were found in nine chaetodontid species at three localities. These specimens are shown, on the basis of combined morphological and molecular analyses, to comprise a complex of morphologically similar and partly cryptic species. The complex may comprise as many as six distinct species of which three are resolved here. The true P. glebulae is identified in Chaetodon ornatissimus Cuvier, 1831, Chaetodon aureofasciatus Macleay, 1878, Chaetodon plebeius Cuvier, 1831, Chaetodon rainfordi McCulloch, 1923 and Chaetodon speculum Cuvier, 1831. Two new species are described, Paradiscogaster munozae n. sp. from Heniochus varius (Cuvier, 1829), Heniochus chrysostomus Cuvier, 1831 and Chaetodon citrinellus Cuvier, 1831 and Paradiscogaster melendezi n. sp. from Chaetodon kleinii Bloch, 1790. In terms of morphology the three species differ most clearly in the development of the appendages on the ventral sucker. The three species differ at 3-6consistent bp of ITS2 rDNA. The host-specificity of the three species differs strikingly. P. melendezi n. sp. infects just one fish species, P. glebulae infects species of only one clade of Chaetodon, and P. munozae n. sp. infects quite unrelated species. The basis of this unusual pattern of host-specificity requires further exploration. Two of the species recognised here, P. glebulae and P. munozae n. sp., showed apparent intra-individual variation in the ITS2 rDNA sequences as demonstrated by clear, replicated double peaks in the electropherograms.

  17. Epidemiological and molecular data on heterophyid trematode metacercariae found in the muscle of grey mullets (Osteichthyes: Mugilidae) from Sardinia (western Mediterranean Sea).

    Science.gov (United States)

    Masala, Simonetta; Piras, Maria Cristina; Sanna, Daria; Chai, Jong-Yil; Jung, Bong-Kwang; Sohn, Woon-Mok; Garippa, Giovanni; Merella, Paolo

    2016-09-01

    This study is a contribution to the molecular taxonomy and epidemiology of heterophyid (Trematoda: Heterophyidae) metacercariae found in the muscle of Mugilidae (Osteichthyes) from Sardinia (western Mediterranean Sea). Sixty specimens of mugilids (13 Chelon labrosus, 18 Liza aurata, 6 Liza ramada, 8 Liza saliens, 15 Mugil cephalus) were examined and 17,899 metacercariae isolated in 95 % of the hosts. Four types of metacercariae were identified: Heterophyes sp. (n = 14,113), Heterophyes sp. -small (1225), Stictodora sp. (1606), and Ascocotyle (Phagicola) sp. (955). The experimental infection of a hamster with Heterophyes sp. metacercariae produced six adults identified as Heterophyes heterophyes and two as Heterophyes cf. nocens. The morphology of Heterophyes sp. -small metacercariae matched with that of Heterophyes dispar. The sequence analysis of the ITS2 and 28S portions of rDNA confirmed the morphological identification of metacercariae, showing four clusters. All adults grouped together with the Heterophyes sp. metacercariae, whereas adults of Heterophyes nocens from Korea clustered separately, showing that this species is distinguished from H. heterophyes, and suggesting caution in the exclusive use of the number of rodlets of the genital sucker to separate the two species. The presence of metacercariae was high in all hosts; the highest prevalence is of Heterophyes sp. (prevalence ≥78 %; mean intensity ≥135 metacercariae/100 g muscle), and the most heavily infected host is M. cephalus (prevalence = 100 %; mean intensity = 841 metacercariae/100 g muscle).

  18. Fish parasites in the Arctic deep-sea: Poor diversity in pelagic fish species vs. heavy parasite load in a demersal fish

    Science.gov (United States)

    Klimpel, Sven; Palm, Harry Wilhelm; Busch, Markus Wilhelm; Kellermanns, Esra; Rückert, Sonja

    2006-07-01

    A total of 219 deep-sea fishes belonging to five families were examined for the parasite fauna and stomach contents. The demersal fish Macrourus berglax, bathypelagic Bathylagus euryops, and mesopelagic Argentina silus, Borostomias antarcticus, Chauliodus sloani, and Lampanyctus macdonaldi were caught at 243-708 m trawling depth in the Greenland and the Irminger Sea in 2002. A total of 21 different parasite species, six Digenea, one Monogenea, two Cestoda, seven Nematoda, one Acanthocephala, and four Crustacea, were found. The parasite diversity in the meso- and bathypelagic environment was less diverse in comparison to the benthal. Macrourus berglax had the highest diversity (20 species), usually carrying 4-10 different parasite species (mean 7.1), whereas Bathylagus euryops harbored up to three and Argentina silus, Borostomias antarcticus, Chauliodus sloani and Lampanyctus macdonaldi each up to two species. Most Digenea, Cestoda, Nematoda, Acanthocephala, and Crustacea are known from a wide host range. Several of the encountered parasites occurred at a very low prevalence (<10%), indicating that the studied deep-sea fishes are most probably not instrumental to complete the parasite life cycles in the area of investigation. It is suggested that the lack of nutrients in the meso- and bathypelagial limits the abundance of potential first intermediate hosts of nematodes and cestodes, resulting in low infestation rates even of widely distributed, non-specific species. In contrast, the higher biomass in the benthic deep-sea environment increases the availability of potential intermediate hosts, such as molluscs for the digeneans, resulting in increased parasite diversity. Because many deep-sea fish have a generalistic feeding behavior, the observed different parasite diversity reflects a different depth range of the fish and not necessarily a specific fish feeding ecology.

  19. Morphological and molecular characterization of the metacercaria of Paragonimus caliensis, as a separate species from P. mexicanus in Costa Rica.

    Science.gov (United States)

    Hernández-Chea, Roderico; Jiménez-Rocha, Ana Eugenia; Castro, Ruth; Blair, David; Dolz, Gaby

    2017-04-01

    The trematode Paragonimus mexicanus is the etiological agent of paragonimiasis, a food-borne zoonotic disease in Latin America. This species, as well as Paragonimus caliensis, have been reported from Costa Rica, but it is not known if the two are synonymous. Two types of Paragonimus metacercariae from freshwater pseudothelphusid crabs from several localities in Costa Rica were recognized by light microscopy. Morphologically, these corresponded to descriptions of P. mexicanus and P. caliensis. Metacercariae of the former species lacked a membrane or cyst and their bodies were yellow in color. Those of P. caliensis were contained in a transparent thin cyst and were pink in color. Morphotypes of metacercariae were determined using scanning electron microscopy (SEM). Based on the number and distribution of papillae in the ventral sucker, three morphotypes were found for P. mexicanus and two for P. caliensis. Analysis of DNA sequences (nuclear ribosomal 28S and ITS2 genes, and partial mitochondrial cox1 gene) confirmed the presence of P. mexicanus and provided the first molecular data for P. caliensis. The two species are phylogenetically distinct from each other and distant from the Asian species. The confirmation of P. caliensis as a separate species from P. mexicanus raises several questions about the ecology, biological diversity, and epidemiology of the genus Paragonimus in Costa Rica.

  20. [Ciliary activity of cells of gill and leg glimmeral epithelium of Unionidae invaded by trematodes of Aspidogaster conchicola and Bucephalus polymorphus].

    Science.gov (United States)

    Chernomaz, T V

    2001-01-01

    The paper provides data concerning the influence of the parasitic worms Aspidogaster conchicola and Bucephalus polymorphus on the rate and duration of ciliary beating of gill and leg in 7 species of Unionidae (Unio conus borysthenicus, U. tumidus falcatulus, U. rostratus rostratus, U. limosus graniger, U. pictorum ponderosus, Colletopterum piscinale falcatum, C. ponderosum rumanicum). The high level of infection of molluscs with B. polymorphus oppresses the glimmeral epithelium activity of gill and leg (by 4.2-32.3%). The weak and moderate levels of infection of molluscs with B. polymorphus do not decrease the glimmeral epithelium activity and sometimes even rise it (by 3.4-8.1%). The presence of few A. conchicola (1-3 individuals) in the organism of mollusc does not change the functioning of glimmeral epithelium.

  1. A new species of Auriculostoma (Trematoda: Allocreadiidae) from the intestine of Brycon guatemalensis (Characiformes: Bryconidae) from the Usumacinta River Basin, Mexico, based on morphology and 28S rDNA sequences, with a key to species of the genus.

    Science.gov (United States)

    Hernández-Mena, David Iván; Lynggaard, Christina; Mendoza-Garfias, Berenit; DE León, Gerardo Pérez-Ponce

    2016-11-22

    We describe a new species of Auriculostoma Scholz, Aguirre-Macedo & Choudhury, 2004 based on several sources of information including morphology (light and scanning electron microscopy [SEM]), sequences of two nuclear genes, host association, and geographical distribution. Morphologically, the new species most closely resembles Auriculostoma astyanace Scholz, Aguirre-Macedo & Choudhury, 2004, but differs by having deeply lobated testes and cirrus-sac extending posteriorly to seminal receptacle level. Auriculostoma lobata n. sp. can be readily distinguished from all the other congeners by the combination of the following characters: testes located in tandem, testes deeply lobated, and larger body size. A phylogenetic analysis using 28S rDNA sequences along with those available for other allocreadiid trematodes, revealed that the new species is a sister taxon of A. astyanace, a species described from the banded astyanax, Astyanax fasciatus (Cuvier) in Nicaragua. Auriculostoma totonacapanensis Razo-Mendivil, Mendoza-Garfias, Pérez-Ponce de León & Rubio-Godoy, 2014 from the Mexican tetra, Astyanax mexicanus (De Filippi) in Mexico is the sister taxon of A. astyanace plus the new species. Genetic divergence levels for the 28S rDNA and ITS2 were estimated among the Middle-American species of Auriculostoma infecting characiforms. The validity of the new species is then established by reliable morphological differences, its host association to bryconids (Brycon guatemalensis Regan), restricted geographical distribution (Usumacinta and Lacantun River basins), and genetic divergence levels, albeit relatively low. A morphometric comparison between the new species and the other seven congeneric species was undertaken and, in addition, a taxonomic key to identify the species contained in the genus Auriculostoma, widely distributed across the Americas, is provided.

  2. Increased parasitism of limpets by a trematode metacercaria in fisheries management areas of central Chile: effects on host growth and reproduction : management areas and parasitism.

    Science.gov (United States)

    Aldana, Marcela; Pulgar, José M; Orellana, Nathalie; Patricio Ojeda, F; García-Huidobro, M Roberto

    2014-06-01

    The rapid increase in body size and abundance of most species inside Management and Exploitations Areas for Benthic Resources (MEABRs) has led to the proposal of these areas as a good complement for achieving the conservation objectives of Marine Protected Areas (MPAs). However, when evaluating MEABRs and MPAs as conservation and/or management tools, their impact upon parasite populations has rarely been considered, despite the fact that epidemiological theory suggests an increased susceptibility to parasitism under high population abundance. We evaluated the effects of MEABRs on the parasite abundance of Proctoeces lintoni and its impact on the growth of the host limpet Fissurella crassa in central Chile. Parasitic magnitude was higher inside MEABRs than in Open-Access Areas, and parasitized limpets showed a greater shell length, muscular foot biomass, and gonadosomatic index compared to non-parasitized limpets of the same age. Our results suggest that the life cycle of P. lintoni and, consequently, its trophic links have been strengthened inside MEABRs. The increased growth rate could reduce the time required to reach the minimum catch size and increase the reproductive and muscular output of the host population. Thus, parasitism should be considered in the conservation and management of economically important mollusk hosts.

  3. Macroparasite communities in European eels, Anguilla anguilla, from French Mediterranean lagoons, with special reference to the invasive species Anguillicola crassus and Pseudodactylogyrus spp.

    Directory of Open Access Journals (Sweden)

    G. Fazio

    2008-01-01

    Full Text Available European eel parasites, in particular invasive species, are suspected to play a role in the decline in the populations of their host. The aims of this work were to describe the parasitic fauna of eels in French Mediterranean lagoons and to study the epidemiological trends of the invasive helminth species, the nematode Anguillicola crassus and the monogenean Pseudodactylogyrus spp., in regard to spatio-temporal dynamics, host biological characteristics and parasite community. A total of 418 eels was sampled in eight lagoons between March 2003 and June 2005. Our results revealed a total macroparasite richness of 23 species: 1 Monogenea, 13 Digenea, 2 Cestoda, 3 Nematoda, 2 Acantocephala and 2 Crustacea. We found no variation in A. crassus abundance in Salses-Leucate lagoon in the same month across years. However, the nematode abundance was higher in eels caught in summer than in those caught in winter. Pseudodactylogyrus sp. was not found in Salses-Leucate lagoon, except in July 2004. Comparisons between the lagoons on the same date showed that they could be separated into two groups for both species' abundance: Grau-du-Roi, Mauguio, Palavas and Vaccarès lagoons, where abundance was rather high, against Bages-Sigean, Pierre-Blanche, Salses-Leucate and Thau lagoons, where abundance was rather low or nil. We found significant negative relationships between A. crassus abundance and the length and age of eels. We also found a significant positive relationship between A. crassus and Pseudodactylogyrus sp. abundance. Finally, our results showed significant positive relationships between both A. crassus and Pseudodactylogyrus sp. abundance and the abundance of the digeneans Prosorhynchus aculeatus and Lecithochirium gravidum. We discuss the results in regard to the dynamics of invasions, the characteristics of the parasite life cycles and the ecology of eels.

  4. Macroparasite communities in European eels, Anguilla anguilla, from French Mediterranean lagoons, with special reference to the invasive species Anguillicola crassus and Pseudodactylogyrus spp.

    Directory of Open Access Journals (Sweden)

    Fazio G.

    2009-04-01

    Full Text Available European eel parasites, in particular invasive species, are suspected to play a role in the decline in the populations of their host. The aims of this work were to describe the parasitic fauna of eels in French Mediterranean lagoons and to study the epidemiological trends of the invasive helminth species, the nematode Anguillicola crassus and the monogenean Pseudodactylogyrus spp., in regard to spatio-temporal dynamics, host biological characteristics and parasite community. A total of 418 eels was sampled in eight lagoons between March 2003 and June 2005. Our results revealed a total macroparasite richness of 23 species: 1 Monogenea, 13 Digenea, 2 Cestoda, 3 Nematoda, 2 Acantocephala and 2 Crustacea. We found no variation in A. crassus abundance in Salses-Leucate lagoon in the same month across years. However, the nematode abundance was higher in eels caught in summer than in those caught in winter. Pseudodactylogyrus sp. was not found in Salses-Leucate lagoon, except in July 2004. Comparisons between the lagoons on the same date showed that they could be separated into two groups for both species' abundance: Grau-du-Roi, Mauguio, Palavas and Vaccarès lagoons, where abundance was rather high, against Bages-Sigean, Pierre-Blanche, Salses-Leucate and Thau lagoons, where abundance was rather low or nil. We found significant negative relationships between A. crassus abundance and the length and age of eels. We also found a significant positive relationship between A. crassus and Pseudodactylogyrus sp. abundance. Finally, our results showed significant positive relationships between both A. crassus and Pseudodactylogyrus sp. abundance and the abundance of the digeneans Prosorhynchus aculeatus and Lecithochirium gravidum. We discuss the results in regard to the dynamics of invasions, the characteristics of the parasite life cycles and the ecology of eels.

  5. Influência do parasitismo por monogeas no desenvolvimento de tilápias-do-Nilo (Oreochromis niloticus (Linnaeus, 1757 criadas em sistemas de tanques-rede na represa de Capivara, PR The influence of branchial parasitism by monogenoid trematodes on the development of Nile tilapia(Oreochromis niloticus Linnaeus, 1757 bred in net-pond systems in Capivara Dam, PR

    Directory of Open Access Journals (Sweden)

    Rodrigo Zanolo

    2009-03-01

    Full Text Available Neste trabalho foi avaliada a influência do parasitismo branquial por monogenóideos no desenvolvimento de tilápias-do-nilo criadas em 4 tanques-rede, com volume de 4 m3 cada, durante aproximadamente 5 meses. Os peixes juvenis, apresentando peso médio inicial de 37,65 g provenientes de outras pisciculturas, foram estocados na densidade de 250 animais.m-3 e monitorados mensalmente até sua comercialização com peso médio final de 485,4 g. A prevalência desses ectoparasitas apresentou-se alta, entre 90 e 100% em todos os meses. Os maiores valores de intensidade média de infestação - IMI e abundância média de infestação - AM ocorreram durante os 2 primeiros meses de cativeiro, apresentando um novo aumento no último mês de criação. Os únicos parasitos da classe Monogenoidea presentes nas brânquias dos animais examinados foram da família Dactylogyridae. Os valores de oxigênio dissolvido, temperatura, pH, nitrito e amônia estiveram dentro da normalidade. Nessas condições, não houve diferenças significativas entre o fator de condição relativo - Kn médio entre os animais parasitados e não parasitados e também nos diferentes níveis de infestação. Assim mostrou que, dentro dessas condições de criação, a relação parasito-hospedeiro-ambiente apresentou- se em equilíbrio sem causar grandes prejuízos aos animais.Tilapias are fish originally from Africa which nowadays are commercially bred in almost 100 countries, being one of the most commercially bred species in the world. In this work the trematode population of the monogenoidea group present in the branchiae of Nile tilapias bred in 4 net-ponds with volume of 4 m3 each, was monitored during 5 months. The juvenile fish, presenting initial average weight of 37.65 g originated from other piscicultures, were stocked in the density of 250 animals.m-3 and monthly monitored until their commercialization, with final average weight of 485.4 g. The prevalence of these

  6. Infection, specificity and host manipulation of Australapatemon sp. (Trematoda, Strigeidae) in two sympatric species of leeches (Hirudinea).

    Science.gov (United States)

    Karvonen, Anssi; Faltýnková, Anna; Choo, Jocelyn Mah; Valtonen, E Tellervo

    2017-09-01

    Factors that drive parasite specificity and differences in infection dynamics among alternative host species are important for ecology and evolution of host-parasite interactions, but still often poorly known in natural systems. Here, we investigated spatiotemporal dynamics of infection, host susceptibility and parasite-induced changes in host phenotype in a rarely explored host-parasite system, the Australapatemon sp. trematode infecting two sympatric species of freshwater leeches, Erpobdella octoculata and Helobdella stagnalis. We show significant variation in infection abundance between the host species in both space and time. Using experimental infections, we also show that most of this variation likely comes from interspecific differences in exposure rather than susceptibility. Moreover, we demonstrate that the hiding behaviour of E. octoculata, but not that of H. stagnalis, was impaired by the infection irrespective of the parasite abundance. This may increase susceptibility of E. octoculata to predation by the final avian host. We conclude that differences in patterns of infection and in behavioural alterations among alternative sympatric host species may arise in narrow spatial scales, which emphasises the importance of local infection and transmission dynamics for parasite life cycles.

  7. Marine protected areas facilitate parasite populations among four fished host species of central Chile.

    Science.gov (United States)

    Wood, Chelsea L; Micheli, Fiorenza; Fernández, Miriam; Gelcich, Stefan; Castilla, Juan Carlos; Carvajal, Juan

    2013-11-01

    1. Parasites comprise a substantial proportion of global biodiversity and exert important ecological influences on hosts, communities and ecosystems, but our knowledge of how parasite populations respond to human impacts is in its infancy. 2. Here, we present the results of a natural experiment in which we used a system of highly successful marine protected areas and matched open-access areas in central Chile to assess the influence of fishing-driven biodiversity loss on parasites of exploited fish and invertebrate hosts. We measured the burden of gill parasites for two reef fishes (Cheilodactylus variegatus and Aplodactylus punctatus), trematode parasites for a keyhole limpet (Fissurella latimarginata), and pinnotherid pea crab parasites for a sea urchin (Loxechinus albus). We also measured host density for all four hosts. 3. We found that nearly all parasite species exhibited substantially greater density (# parasites m(-2)) in protected than in open-access areas, but only one parasite species (a gill monogenean of C. variegatus) was more abundant within hosts collected from protected relative to open-access areas. 4. These data indicate that fishing can drive declines in parasite abundance at the parasite population level by reducing the availability of habitat and resources for parasites, but less commonly affects the abundance of parasites at the infrapopulation level (within individual hosts). 5. Considering the substantial ecological role that many parasites play in marine communities, fishing and other human impacts could exert cryptic but important effects on marine community structure and ecosystem functioning via reductions in parasite abundance.

  8. Molecular identification of Austrobilharzia species parasitizing Cerithidea cingulata (Gastropoda: Potamididae) from Kuwait Bay.

    Science.gov (United States)

    Al-Kandari, W Y; Al-Bustan, S A; Isaac, A M; George, B A; Chandy, B S

    2012-12-01

    Avian schistosomes belonging to the genus Austrobilharzia (Digenea: Schistosomatidae) are among the causative agents of cercarial dermatitis in humans. In this paper, ribosomal and mitochondrial DNA sequences were used to study schistosome cercariae from Kuwait Bay that have been identified morphologically as Austrobilharzia sp. Sequence comparison of the ribosomal DNA (rDNA) 28S and 18S regions of the collected schistosome cercariae with corresponding sequences of other schistosomes in GenBank revealed high sequence similarity. This confirmed the morphological identification of schistosome cercariae from Kuwait Bay as belonging to the genus Austrobilharzia. The finding was further supported by the phylogenetic tree that was constructed based on the combined data set 18S-28S-mitochondrial cytochrome oxidase I (mtCO1) sequences in which Austrobilharzia sp. clustered with A. terrigalensis and A. variglandis. Sequence comparison of the Austrobilharzia sp. from Kuwait Bay with A. variglandis and A. terrigalensis based on mtCO1 showed a variation of 10% and 11%, respectively. Since the sequence variation in the mtCO1 was within the interspecific range among trematodes, it seems that the Austrobilharzia species from Kuwait Bay is different from the two species reported in GenBank, A. terrigalensis and A. variglandis.

  9. Canine schistosomiasis In North America: an underdiagnosed disease with an expanding distribution.

    Science.gov (United States)

    Johnson, Eileen M

    2010-03-01

    Heterobilharzia americana, a digenean trematode in the family Schistosomatidae, is the etiologic agent of canine schistosomiasis in the southeastern United States. A few cases of canine schistosomiasis have been reported in Florida, Louisiana, North Carolina, Texas, and, recently, Kansas. The natural definitive host for the fluke is the raccoon; however, infections have been detected in nutrias, bobcats, mountain lions, opossums, white-tailed deer, swamp rabbits, armadillos, coyotes, red wolves, red wolf-coyote crosses, Brazilian tapirs, minks, and beavers.

  10. Transversotrema Witenberg, 1944 (Trematoda: Transversotrematidae) from inshore fishes of Australia: description of a new species and significant range extensions for three congeners.

    Science.gov (United States)

    Cutmore, Scott C; Diggles, Ben K; Cribb, Thomas H

    2016-09-01

    Four transversotrematid trematodes are reported from commercial teleost species in Australian waters. Transversotrema hunterae n. sp. is described from three species of Sillago Cuvier (Sillaginidae) from Moreton Bay, south-east Queensland. Molecular characterisation using ITS2 rDNA confirmed this stenoxenic specificity of Transversotrema hunterae n. sp., with identical sequence data from Sillago maculata Quoy & Gaimard, S. analis Whitley and S. ciliata Cuvier. Phylogenetic analysis, based on 28S rDNA data, demonstrates that T. hunterae n. sp. belongs to the 'Transversotrema licinum clade' and is most closely related to Transversotrema licinum Manter, 1970 and T. polynesiae Cribb, Adlard, Bray, Sasal & Cutmore, 2014, with the three species forming a well-supported clade in all analyses. We extend the known host and geographical ranges of three previously described Transversotrema species, T. licinum, T. elegans Hunter, Ingram, Adlard, Bray & Cribb, 2010 and T. espanola Hunter & Cribb, 2012. The new records represent significant range extensions for the three species and permit further examination of the patterns of biogeographical distribution in Australian waters. Host-specificity of Transversotrema species is examined, and the degree to which morphological analysis can inform taxonomic studies of this group is discussed.

  11. Monitoring of Fasciola Species Contamination in Water Dropwort by cox1 Mitochondrial and ITS-2 rDNA Sequencing Analysis.

    Science.gov (United States)

    Choi, In-Wook; Kim, Hwang-Yong; Quan, Juan-Hua; Ryu, Jae-Gee; Sun, Rubing; Lee, Young-Ha

    2015-10-01

    Fascioliasis, a food-borne trematode zoonosis, is a disease primarily in cattle and sheep and occasionally in humans. Water dropwort (Oenanthe javanica), an aquatic perennial herb, is a common second intermediate host of Fasciola, and the fresh stems and leaves are widely used as a seasoning in the Korean diet. However, no information regarding Fasciola species contamination in water dropwort is available. Here, we collected 500 samples of water dropwort in 3 areas in Korea during February and March 2015, and the water dropwort contamination of Fasciola species was monitored by DNA sequencing analysis of the Fasciola hepatica and Fasciola gigantica specific mitochondrial cytochrome c oxidase subunit 1 (cox1) and nuclear ribosomal internal transcribed spacer 2 (ITS-2). Among the 500 samples assessed, the presence of F. hepatica cox1 and 1TS-2 markers were detected in 2 samples, and F. hepatica contamination was confirmed by sequencing analysis. The nucleotide sequences of cox1 PCR products from the 2 F. hepatica-contaminated samples were 96.5% identical to the F. hepatica cox1 sequences in GenBank, whereas F. gigantica cox1 sequences were 46.8% similar with the sequence detected from the cox1 positive samples. However, F. gigantica cox1 and ITS-2 markers were not detected by PCR in the 500 samples of water dropwort. Collectively, in this survey of the water dropwort contamination with Fasciola species, very low prevalence of F. hepatica contamination was detected in the samples.

  12. Secondary structure analysis of ITS2 in the rDNA of three Indian paramphistomid species found in local livestock.

    Science.gov (United States)

    Shylla, Jollin A; Ghatani, Sudeep; Chatterjee, Anupam; Tandon, Veena

    2011-04-01

    Of paramphistomid trematodes, three species viz., Homalogaster paloniae, Calicophoron calicophorum and Orthocoelium streptocoelium are commonly prevalent in bovine hosts in Northeast India. The aim of the present study was to genetically characterise these species using rDNA second internal transcribed spacer (ITS2) so as to supplement the morphological criteria substantiated by molecular findings. The annotated ITS2 region from H. paloniae, C. calicophorum and O. streptocoelium were found to be 289 bp, 288 bp and 288 bp long, respectively. On comparison, the Indian isolates of the three species were observed to have a maximum identity of 99% with each of their respective counterparts from Japan. The secondary structure models were inferred using minimum free energy modelling algorithms. The paramphistomes displayed the typical four helix ITS2 secondary structure and differed from each other due to minor nucleotide differences. The consensus ITS2 secondary structure model revealed the presence of conservative motifs GACGAGGGUG and GCGGUAGAGUC in helix III. Monophyly is well supported for a clade consisting of the Japanese and Indian paramphistomes with significant bootstrap values.

  13. Species accounts. Chapter 4

    Science.gov (United States)

    Margaret K. Trani; W. Mark Ford; Brian R., eds. Chapman

    2007-01-01

    Narrative accounts for each species are presented by several authors in a consistent format to convey specific information relative to that mammal. The orders are arranged phylogenetically; families and species are arranged alphabetically to facilitate finding a particular species.

  14. Six new species of Lepidapedon Stafford, 1904 (Digenea: Lepocreadiidae) from deep-sea macrourid fishes from the Gulf of Mexico and Caribbean Sea, with revised keys to the species of the genus.

    Science.gov (United States)

    Blend, C K; Dronen, N O; Armstrong, H W

    2000-01-01

    . cascadensis and L. genge in having a smaller egg size, a shorter prepharynx and oesophagus than pharynx, and vitelline fields that are intertesticular but only slightly encroach between the ovary and anterior testis. L. sammari and L. spiniferi are designated as incertae sedis, and L. quiloni and L. stromateusi are designated as species inquirendae. New parasite keys and host records for Coelorinchus coelorhincus. C. caribbaeus and Nezumia cyrano are offered. Support is given to Lepidapedon probably being the dominant digenean genus in deep water.

  15. Richness and diversity of helminth species in eels from a hypersaline coastal lagoon, Mar Menor, south-east Spain.

    Science.gov (United States)

    Mayo-Hernández, E; Peñalver, J; García-Ayala, A; Serrano, E; Muñoz, P; Ruiz de Ybáñez, R

    2015-05-01

    The composition and diversity of parasite communities and intestinal components, as well as infra-community structure, were assessed in eels Anguilla anguilla, from Mar Menor, a permanent Mediterranean hypersaline coastal lagoon. Data were used to determine whether this helminth community differs in composition and structure from that of eels in lagoons with lower salinity regimes and higher freshwater inputs. A total prevalence of 93% was detected. Specifically, parasites were identified as Deropristis inflata, Bucephalus anguillae, Contracaecum sp., Anguillicoloides crassus and two plerocercoid larvae belonging to the order Proteocephalidae, the marine species representing 91% of the isolated helminths. In the total community, digenetic trematodes were the dominant group of helminths, and D. inflata, an eel specialist, dominated both the component community and the infra-community. Richness and diversity were low but similar to those reported in other saline lagoons, and maximum species per eel did not exceed four. At the infra-community level, higher abundance than in other brackish or marine Mediterranean environments was detected. The findings provide further evidence of the similarity in composition and structure of helminth communities in eels from various Mediterranean coastal lagoons. Moreover, salinity-dependent specificities are well supported and reflect the life history of individual eels.

  16. Dicrocoelium chinensis and Dicrocoelium dendriticum (Trematoda: Digenea) are distinct lancet fluke species based on mitochondrial and nuclear ribosomal DNA sequences.

    Science.gov (United States)

    Liu, Guo-Hua; Yan, Hong-Bin; Otranto, Domenico; Wang, Xing-Ye; Zhao, Guang-Hui; Jia, Wan-Zhong; Zhu, Xing-Quan

    2014-10-01

    Lancet flukes parasitize the bile ducts and gall bladder of a range of mammals, including humans, causing dicrocoeliosis. In the present study, we sequenced and characterized the complete mitochondrial (mt) genomes as well as the first and second internal transcribed spacers (ITS-1 and ITS-2=ITS) of nuclear ribosomal DNA (rDNA) of two lancet flukes, Dicrocoelium chinensis and D. dendriticum. Sequence comparison of a conserved mt gene and nuclear rDNA sequences among multiple individual lancet flukes revealed substantial nucleotide differences between the species but limited sequence variation within each of them. Phylogenetic analysis of the concatenated amino acid and multiple mt rrnS sequences using Bayesian inference supported the separation of D. chinensis and D. dendriticum into two distinct species-specific clades. Results of the present study support the proposal that D. dendriticum and D. chinensis represent two distinct lancet flukes. While providing the first mt genomes from members of the superfamily Plagiorchioidea, the novel mt markers described herein will be useful for further studies of the diagnosis, epidemiology and systematics of the lancet flukes and other trematodes of human and animal health significance.

  17. Phylogenetic analysis reveals cryptic species diversity within minute intestinal fluke, Stellantchasmus falcatus Onji and Nishio, 1916 (Trematoda, Heterophyidae).

    Science.gov (United States)

    Wongsawad, Chalobol; Nantarat, Nattawadee; Wongsawad, Pheravut

    2017-02-01

    To examine the taxonomic boundaries in the Stellantchasmus populations in different hosts and reveal the cryptic speciation of the Stellantchasmus in Thailand based on both morphological and molecular approaches. Stellantchasmus falcatus (S. falcatus) s.l. was collected from different hosts throughout Thailand. The worms were examined and measured. The nuclear ITS2 gene and the mitochondrial COI gene were used to investigate the S. falcatus s.l. from Dermogenus pusillus and Liza subviridis. Stellantchasmus was one of food-borne trematode that widely distribute throughout Thailand. The comparison of S. falcatus s.l. from Dermogenus pusillus and Liza subviridis indicated a genetic divergence of nuDNA with 3.6% and mtDNA with 19.3%, respectively. Morphological characteristics were fairly different in the ratio of body size, length of prepharynx, and ratio of organ size. Our results provide initial evidence that S. falcatus s.l. from different hosts tend to be a different species based on both molecular and morphological characters. Cryptic species complexes are generally found among parasites that tend to have large populations and/or rapid evolution. The degree of genetic diversity existing would suggest the practice of targeted regimes to design and minimize these lections of anthelmintic resistance in the future. Copyright © 2017 Hainan Medical University. Production and hosting by Elsevier B.V. All rights reserved.

  18. Agroforestry Species Switchboard

    DEFF Research Database (Denmark)

    Kindt, R.; John, I.; Ordonez, J.;

    2016-01-01

    The current version of the Agroforestry Species Switchboard documents the presence of a total of 26,135 plant species (33,813 species including synonyms) across 19 web-based databases. When available, hyperlinks to information on the selected species in particular databases are provided. In total...

  19. Agroforestry Species Switchboard

    DEFF Research Database (Denmark)

    Kindt, R.; John, I.; Ordonez, J.

    2016-01-01

    The current version of the Agroforestry Species Switchboard documents the presence of a total of 26,135 plant species (33,813 species including synonyms) across 19 web-based databases. When available, hyperlinks to information on the selected species in particular databases are provided. In total...

  20. Descriptions of diplostomid metacercariae (Digenea: Diplostomidae from freshwater fishes in the Tshwane area

    Directory of Open Access Journals (Sweden)

    Esmey B.E. Moema

    2013-03-01

    Full Text Available The metacercarial (larval stages of diplostomid digeneans are known to inhabit freshwater fish, causing tissue damage in the process. Due to their widespread diversity, little is known about their life cycle. The classification of these parasitic stages to the species level using only the morphology is very challenging due to the lack of genitalia; they are regarded to be the most important structures in the identification of these organisms. In this study, additional morphological information through light and scanning electron microscopy is given for two different diplostomids found in the cranial cavity of Clarias gariepinus and the vitreous chambers of Tilapia sparrmanii and Pseudocrenilabrus philander. The diplostomid metacercaria inhabiting the cranial cavity of Clarias gariepinus was morphologically identified as Diplostomulum (Tylodelphys mashonenseand an unknown metacercaria of the genus Diplostomumwas found in the vitreous chambers of Pseudocrenilabrus philander and Tilapia sparrmanii. Both parasitic species’ 28S recombinant deoxyribonucleic acid genomic regions were successfully amplified using Dig 125/1500R primer pairs. The assay yielded a product of approximately 1300 base pairs as seen on the gel images. There were 14 nucleotide differences over the entire analysed sequences resulting in a 1.1% (14/1273 nucleotide difference. In line with the morphological characteristics of these parasites, there seemed to be a slight difference in their genetic makeup. The application of molecular techniques on digenetic trematodes seems very promising and may yield great potential in future descriptions of morphologically similar parasitic species.

  1. Rodent hosts of Maritrema sp. (Digenea, Microphallidae in Sardinia Island

    Directory of Open Access Journals (Sweden)

    Juan Carlos Casanova

    2003-10-01

    Full Text Available Prospections on helminth fauna of rodents were carried out in the Cedrino river (Eastern of Sardinia island. Twelve Rattus rattus (L., 1758 and eight Mus domesticus (Schwarz & Schwarz, 1943 were captured by Sherman traps. Parasitological study revealed in R. rattus the presence of an intestinal helminth belonging to the genus Maritrema (family Microphallidae. The transmission of this Digenetic Trematode among vertebrates involves the participation of aquatic invertebrate organisms, molluscs and crustacea, acting as intermediate hosts. Dissection of 117 individuals of the Amphipod Crustacea Gammarus italicus, collected in the same biotope, allowed the detection of encysted metacercariae. These larvae constitute the infesting stage of the parasite for vertebrates, acting these as definitive hosts ingesting parasitized crustacea as preys. Adults of Maritrema sp. were also obtained experimentally in the laboratory mice (Mus domesticus CD1 strain. These were infested by inoculating them, using gastric probe, metacercarial cysts isolated from G. italicus. Post-infection mice dissection was performed at different intervals of time getting adults in various maturity stages. Experimental facts confirm that Maritrema sp., as it occurs in other trematodes, do not present strict specificity to the definitive host, being able to develop as well in Mus. In nature, the presence or absence of this digenean in mammals species will be dependent of host ethological factors, mainly related to feeding habitats. This study was partially supported by the ?Comissionat per Recerca i Universitats de la Generalitat de Catalunya? 2001SGR00088.

  2. Morphology and molecules reveal the alien Posthodiplostomum centrarchi Hoffman, 1958 as the third species of Posthodiplostomum Dubois, 1936 (Digenea: Diplostomidae) in Europe.

    Science.gov (United States)

    Stoyanov, Borislav; Georgieva, Simona; Pankov, Plamen; Kudlai, Olena; Kostadinova, Aneta; Georgiev, Boyko B

    2017-01-01

    Metacercariae of two species of Posthodiplostomum Dubois, 1936 (Digenea: Diplostomidae) were subjected to morphological and molecular studies: P. brevicaudatum (von Nordmann, 1832) from Gasterosteus aculeatus (L.) (Gasterosteiformes: Gasterosteidae), Bulgaria (morphology, cox1 and ITS1-5.8S-ITS2) and Perca fluviatilis L. (Perciformes: Percidae), Czech Republic (morphology, cox1, ITS1-5.8S-ITS2 and 28S); and P. centrarchi Hoffman, 1958 from Lepomis gibbosus (L.) (Perciformes: Centrarchidae), Bulgaria (morphology, cox1 and ITS1-5.8S-ITS2) and Slovakia (cox1 and ITS1-5.8S-ITS2). In addition, cercariae of P. cuticola (von Nordmann, 1832) from Planorbis planorbis (L.) (Mollusca: Planorbidae), Lithuania (morphology and cox1) and metacercariae of Ornithodiplostomum scardinii (Schulman in Dubinin, 1952) from Scardinius erythrophthalmus (L.) (Cypriniformes: Cyprinidae), Czech Republic, were examined (morphology, cox1, ITS1-5.8S-ITS2 and 28S). These represent the first molecular data for species of Posthodiplostomum and Ornithodiplostomum Dubois, 1936 from the Palaearctic. Phylogenetic analyses based on cox1 and ITS1-5.8S-ITS2, using O. scardinii as the outgroup and including the three newly-sequenced Posthodiplostomum spp. from Europe and eight published unidentified (presumably species-level) lineages of Posthodiplostomum from Canada confirmed the distinct status of the three European species (contrary to the generally accepted opinion that only P. brevicaudatum and P. cuticola occur in the Palaearctic). The subspecies Posthodiplostomum minimum centrarchi Hoffmann, 1958, originally described from North America, is elevated to the species level as Posthodiplostomum centrarchi Hoffman, 1958. The undescribed "Posthodiplostomum sp. 3" of Locke et al. (2010) from centrarchid fishes in Canada has identical sequences with the European isolates of P. centrarchi and is recognised as belonging to the same species. The latter parasite, occurring in the alien pumpkinseed sunfish

  3. Seasonal variation in parasite infection patterns of marine fish species from the Northern Wadden Sea in relation to interannual temperature fluctuations

    Science.gov (United States)

    Schade, Franziska M.; Raupach, Michael J.; Mathias Wegner, K.

    2016-07-01

    Marine environmental conditions are naturally changing throughout the year, affecting life cycles of hosts as well as parasites. In particular, water temperature is positively correlated with the development of many parasites and pathogenic bacteria, increasing the risk of infection and diseases during summer. Interannual temperature fluctuations are likely to alter host-parasite interactions, which may result in profound impacts on sensitive ecosystems. In this context we investigated the parasite and bacterial Vibrionaceae communities of four common small fish species (three-spined stickleback Gasterosteus aculeatus, Atlantic herring Clupea harengus, European sprat Sprattus sprattus and lesser sand eel Ammodytes tobianus) in the Northern Wadden Sea over a period of two years. Overall, we found significantly increased relative diversities of infectious species at higher temperature differentials. On the taxon-specific level some macroparasite species (trematodes, nematodes) showed a shift in infection peaks that followed the water temperatures of preceding months, whereas other parasite groups showed no effects of temperature differentials on infection parameters. Our results show that even subtle changes in seasonal temperatures may shift and modify the phenology of parasites as well as opportunistic pathogens that can have far reaching consequences for sensitive ecosystems.

  4. Endangered Species Act

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The purpose of the Endangered Species Act (ESA) is to protect and recover imperiled species and the ecosystems upon which they depend. The U.S. Fish and Wildlife...

  5. Invasive forest species

    Science.gov (United States)

    Barbara L. Illman

    2006-01-01

    Nonnative organisms that cause a major change to native ecosystems-once called foreign species, biological invasions, alien invasives, exotics, or biohazards–are now generally referred to as invasive species or invasives. invasive species of insects, fungi, plants, fish, and other organisms present a rising threat to natural forest ecosystems worldwide. Invasive...

  6. Species choice, provenance and species trials among native Brazilian species

    Energy Technology Data Exchange (ETDEWEB)

    Drumond, M.A.

    1982-01-01

    Six papers from the conference are presented. Drumond, M.A., Potential of species native to the semi-arid tropics, 766-781, (Refs. 18), reports on Anadenanthera macrocarpa, Mimosa species, Schinopsis brasiliensis, Spondias tuberosa, Ziziphus joazeiro, Cnidoscolus phyllacanthus, Bursera leptophleos (leptophloeos), Tabebuia impetiginosa, Astronium urundeuva, and Mimosa caesalpinia. Monteiro, R.F.R., Speltz, R.M., Gurgel, J.T. do A.; Silvicultural performance of 24 provenances of Araucaria angustifolia in Parana, 814-824, (Refs. 8). Pires, C.L. da S., Kalil Filho, A.N., Rosa, P.R.F. da, Parente, P.R., Zanatto, A.C.S.; Provenance trials of Cordia alliodora in the State of Sao Paulo, 988-995, (Refs. 9). Nogueira, J.C.B., Siqueira, A.C.M.F., Garrido, M.A.O., Gurgel Garrido, L.M. do A., Rosa, P.R.F., Moraes, J.L. de, Zandarin, M.A., Gurgel Filho, O.A., Trials of some native species in various regions of the State of Sao Paulo, 1051-1063, (Refs. 9) describes Centrolobium tomentosum, Peltophorum dubium, Tabebuia vellosoi, Cariniana legalis, and Balfourodendron riedelianum. Batista, M.P., Borges, J.F., Franco, M.A.B.; Early growth of a native species in comparison with exotics in northeastern Para, Brazil, 1105-1110, (Refs. 3). Jacaranda copaia is compared with Gmelina arborea, Pinus caribaea various hondurensis, Eucalyptus deglupta, and E. urophylla. Lima, P.C.F., Souza, S.M. de, Drumond, M.A.; Trials of native forest species at Petrolina, Pernambuco, 1139-1148, (Refs. 8), deals with Anadenanthera macrocarpa, Piptadenia obliqua, Pithecellobium foliolosum, Astronium urundeuva, Schinopsis brasiliensis, Cassia excelsa, Caesalpinia pyramidalis, Parkia platycephala, Pseudobombax simplicifolium, Tabebuia impetiginosa, Caesalpinia ferrea, and Aspidosperma pyrifolium. 18 references.

  7. Susceptibility of 7 freshwater gastropod species in Zimbabwe to infection with Gastrodiscus aegyptiacus (Cobbold, 1876 Looss, 1896 : short communication

    Directory of Open Access Journals (Sweden)

    S. Mukaratirwa

    2004-06-01

    Full Text Available Gastrodiscosis outbreaks due to Gastrodiscus aegyptiacus were recorded in horses in the vicinity of Harare, Zimbabwe, in the absence of Bulinus forskalii, B. senegalensis and Cleopatra sp. which are considered to be the only intermediate host snails. This suggested the possibility of other snail species acting as intermediate hosts in the life cycle of the trematode. A study was carried out to determine the susceptibility of 7 freshwater snail species to infection with G. aegyptiacus. First generation (F-1 of 5 freshwater pulmonate snail species, Bulinus tropicus, Bulinus globosus, Biomphalaria pfeifferi, Helisoma dyuri and Physa acuta that were bred in the laboratory, and 2 prosobranch snail species, Melanoides tuberculata and Cleopatra sp. that were collected from the field were used in this study. Data pertaining to mortalities and cercariae shedding were recorded throughout the experimental period. The prosobranch snails, M. tuberculata and Cleopatra sp. were susceptible to G. aegyptiacus with a minimum prepatent period of 45 days and 54 days, respectively. Bulinus tropicus, P. acuta and H. duryi were susceptible as evidenced by the presence of different generations of rediae and mature cercariae on dissection at 59 days post-infection although attempts to induce the snails to shed from 28 days post-infection did not produce cercariae. Bulinus globosus and Bio. Pfeifferi were refractory to infection. The results revealed the ability of G. aegyptiacus to infect M. tuberculata, Cleopatara sp., B. tropicus, P. acuta and H. duryi under experimental conditions and this may explain the recorded outbreaks of gastrodiscosis in equine populations in Zimbabwe in the absence of the known intermediate hosts. Bulinus tropicus is considered as the most likely major intermediate host of G. aegyptiacus because of its wide distribution in Zimbabwe and is well adapted to a wide variety of environments.

  8. Histological survey of symbionts and other conditions of pod razor clam Ensis siliqua (Linnaeus, 1758) in Galicia (NW Spain).

    Science.gov (United States)

    Ruiz, Maite; Darriba, Susana; Rodríguez, Rosana; López, Carmen

    2013-01-01

    The aim of the present study was to carry out a survey of parasites and other conditions affecting pod razor clam populations, Ensis siliqua, in two beds from Galicia (NW Spain). In Galicia, the production of E. siliqua has increased in recent years due to the development of specific plans for its exploitation, however few and quite recent pathological studies have been carried out in this species. The results of this study showed the presence of different protozoa as the more prevalent group, especially Nematopsis sp. gregarines, unidentified branchial protozoa, renal coccidia and Trichodina sp. ciliates. Larval stages of trematodes and neoplastic disorders were also observed with lower prevalences. Furthermore, an ultrastructural analysis of two types of unidentified basophilic inclusions, both found in the digestive gland, revealed the presence of icosahedral viral particles and prokaryotic organisms, respectively. None of the parasites detected in E. siliqua from this study was notifiable to the World Organisation for Animal Health (OIE) and the majority of the symbionts and conditions observed in their tissues did not cause host damage. Nevertheless, parasites like bucephalid digenean sporocysts, viral inclusions, prokaryotic infections, disseminated neoplasm or germinoma detected in some samples could cause moderate or severe damage to the host depending on the intensity of infection.

  9. Fine structure and cellular responses at the host-parasite interface in a range of fish-helminth systems.

    Science.gov (United States)

    Dezfuli, B S; Bo, T; Lorenzoni, M; Shinn, A P; Giari, L

    2015-03-15

    A series of ultrastructural-based studies were conducted on the interface region in different fish-helminth systems: (a) an intestinal infection of the cestode Monobothrium wageneri in tench, Tinca tinca; (b) an extensive intestinal submucosa and mucosal infection in tench by metacercariae of an unidentified digenean trematode; (c) an intestinal infection in brown trout, Salmo trutta, by the acanthocephalan Dentitruncus truttae; (d) an extraintestinal infection by larvae of the acanthocephalan, Pomphorhynchus laevis in three-spined sticklebacks, Gasterosteus aculeatus; and (e) an infection in the livers of Eurasian minnow, Phoxinus phoxinus, by larvae of the nematode Raphidascaris acus. Endoparasitic helminths frequently cause inflammation of the digestive tract and associated organs, inducing the recruitment of various immune cells to the site of infection. In each of the fish-helminth systems that were studied, a massive hyperplastic granulocyte response involving mast cells (MCs) and neutrophils in close proximity to the helminths was documented. The current study presents data on the interface region in each fish-helminth system and documents the penetration of mast cells granules within the tegument of P. laevis larvae. No extracellular vesicles containing tegumental secretions from any of the four different taxa of endoparasitic helminths species at the host-parasite interface region were seen.

  10. Two-year intervention trial to control of fish-borne zoonotic trematodes in giant gourami (Osphronemus goramy) and striped catfish (Pangasianodon hypophthalmus) in nursery ponds in the Mekong Delta, Vietnam

    DEFF Research Database (Denmark)

    Madsen, Henry; Thien, P. C.; Nga, H. T. N.

    2015-01-01

    ponds prior to fish stocking, and various other measures in reducing FZT infection in juvenile striped catfish (Pangasianodon hypophthalmus) and giant gourami (Osphronemus goramy). Interventions were implemented on 5 farms for each fish species during production cycles in 2009 and 2010 while 5 similar...... farms for each species served as control. For both fish species, both prevalence and intensity of infection did not differ significantly between intervention and non-intervention farms prior to the interventions. The interventions significantly reduced both prevalence and intensity of FZT infection...... in the juvenile fish compared to control ponds. For giant gourami, odds of infection in intervention ponds was 0.13 (95% CL: 0.09-0.20; p

  11. Support your local species

    DEFF Research Database (Denmark)

    Stärk, Johanna

    Nearly a quarter of all animal species within the European Union are threatened with extinction. Protecting many of these species will require the full spectrum of conservation actions from in-situ to ex-situ management. Holding an estimated 44% of EU Red Listed terrestrial vertebrates, zoos hereby...

  12. The Origin of Species

    NARCIS (Netherlands)

    Darwin, Charles

    2005-01-01

    In The Origin of Species Darwin outlined his theory of evolution, which proposed that species had been evolving and differentiating over time under the influence of natural selection. On its publication it became hugely influential, bringing about a seismic shift in the scientific view of humanitys

  13. The Origin of Species

    NARCIS (Netherlands)

    Darwin, Charles

    2005-01-01

    In The Origin of Species Darwin outlined his theory of evolution, which proposed that species had been evolving and differentiating over time under the influence of natural selection. On its publication it became hugely influential, bringing about a seismic shift in the scientific view of humanitys

  14. Biofilms of Clostridium species.

    Science.gov (United States)

    Pantaléon, Véronique; Bouttier, Sylvie; Soavelomandroso, Anna Philibertine; Janoir, Claire; Candela, Thomas

    2014-12-01

    The biofilm is a microbial community embedded in a synthesized matrix and is the main bacterial way of life. A biofilm adheres on surfaces or is found on interfaces. It protects bacteria from the environment, toxic molecules and may have a role in virulence. Clostridium species are spread throughout both environments and hosts, but their biofilms have not been extensively described in comparison with other bacterial species. In this review we describe all biofilms formed by Clostridium species during both industrial processes and in mammals where biofilms may be formed either during infections or associated to microbiota in the gut. We have specifically focussed on Clostridium difficile and Clostridium perfringens biofilms, which have been studied in vitro. Regulatory processes including sporulation and germination highlight how these Clostridium species live in biofilms. Furthermore, biofilms may have a role in the survival and spreading of Clostridium species. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Extragastric Helicobacter species

    DEFF Research Database (Denmark)

    On, Stephen L.W.; Hynes, S.; Wadstrom, T.

    2002-01-01

    The genus Helicobacter has expanded at a rapid pace and no fewer than 31 species have been named since the proposal of the genus in 1989. Of these 31 species, 22 are principally associated with extragastric niches and there is increasing interest in the role of these taxa in diseases of humans...... and animals. Substantial evidence attests to certain species playing a role in the pathogenesis of enteric, hepatic and biliary disorders and some taxa demonstrate zoonotic potential. The importance of extragastric Helicobacters is likely to be an important topic for research in the near future. Here...

  16. Threatened & Endangered Species Occurrences

    Data.gov (United States)

    Kansas Data Access and Support Center — The database consists of a single statewide coverage of location records for 54 species contained in the Kansas Natural Heritage Inventory database of the Kansas...

  17. DENTURE WEARER: ALCALIGENES SPECIES

    African Journals Online (AJOL)

    associated with Alcaligenes species infection in a patient using an upper single ... patient was HIV negative and VDRL screening for syphilis was also negative. ... status of denture and the underlying oral mucosal, to prevent opportunistic.

  18. Arctic species resilience

    DEFF Research Database (Denmark)

    Mortensen, Lars O.; Forchhammer, Mads C.; Jeppesen, Erik

    and precipitation. Concurrently, phenological change has been recorded in a wide range of plants and animals, with climate change seemingly being the primary driver of these changes. A major concern is whether species and biological systems embrace the plasticity in their phenological responses needed for tracking...... the predicted increase in climate variability. Whereas species may show relatively high phenological resilience to climate change per se, the resilience of systems may be more constrained by the inherent dependence through consumer-resource interactions across trophic levels. During the last 15 years...... Zackenberg Basic, a newly initiated project is focusing on how the changes and variability in the physical environment affects the species phenology and composition, population dynamics and how species specific responses at different trophic levels are carried on to the inter-trophic dynamics of consumers...

  19. Fire Management Species Profiles

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The objective of the Fire Management Species Profile project is to identify habitat management objectives that are specific, measurable, achievable, clearly...

  20. Sub specie aeternitatis

    Directory of Open Access Journals (Sweden)

    Laura Gioeni

    2012-10-01

    Full Text Available Per delineare il rapporto tra etica ed estetica nell'architettura e rispondere alla domanda principale «che cosa è o dovrebbe essere un buon architetto?», il saggio discute la tesi di Wittgenstein secondo cui «l'opera d'arte è l'oggetto visto sub specie aeternitatis e la vita buona è il mondo visto sub specie aeternitatis. Questa è la connessione tra arte ed etica».

  1. Utility of divergent domains of 28S ribosomal RNA in species discrimination of paramphistomes (Trematoda: Digenea: Paramphistomoidea).

    Science.gov (United States)

    Shylla, Jollin A; Ghatani, Sudeep; Tandon, Veena

    2013-12-01

    Among the digenetic trematodes, paramphistomes are known to be the causative agent of "amphistomiasis" or the stomach fluke disease of domestic and wild animals, mainly ruminants. The use of 28S (divergent domains) and 18S rRNA for phylogenetic inference is significantly warranted for these flukes since it is as yet limited to merely the exploration of the second internal transcribed spacer (ITS2) region. The present study intended to explore the divergent domains (D1-D3) of 28S rRNA and simultaneously equate the phylogenetic information with 18S rRNA in paramphistomes. Divergence of the 28S rRNA domains was evident amongst the divergent (D) domains, where D1 domain emerged as the most variable and D2, the most robust domain, since the latter could provide a higher resolution of the species. D2 was the only domain that comprised compensatory mutations in the helices of its structural constraints; this domain is thus well suited for species distinction and may be considered a potential DNA barcode complementary to mitochondrial DNA. 28S (D1 + D2 + D3) rRNA provided a significant resolution of the taxa corroborating with the taxonomy of these flukes and thus proved to be more robust as a phylogenetic marker for lower levels than 18S rRNA. Phylogenetic inferences of paramphitomes are still scarcely explored; additional data from other taxa belonging to this family may estimate better the biodiversity of these flukes.

  2. Two new species of Creptotrema (Digenea: Allocreadiidae from South America Dos especies nuevas de Creptotrema (Digenea: Allocreadiidae de América del Sur

    Directory of Open Access Journals (Sweden)

    Stephen S. Curran

    2008-08-01

    Full Text Available Two new digenean species belonging in Creptotrema Travassos, Artigas and Pereira, 1928 are described from specimens stored in the invertebrate collection at the Museum of Natural History, Geneva, Switzerland. Creptotrema lamothei n. sp. is described from Ageneiosus brevifilis Valenciennes in Cuvier and Valenciennes, 1840 (Siluriformes: Ageneiosidae, Auchenipterus nuchalis (Spix and Agassiz, 1829 (Siluriformes: Auchenipteridae, and Bryconops melanurus (Bloch, 1794 (Characiformes: Characidae in the Paraguay River, Paraguay. Creptotrema sucumbiosa n. sp. is described from Tetragonopterus argenteus Cuvier, 1816 (Characiformes: Characidae in Río Aquarico, Ecuador. Creptotrema lamothei differs from its congeners by having testes with irregular rather than entire outlines. Creptotrema sucumbiosa differs from its congeners by having a bilobed rather than entire ovary. Both C. lamothei and C. sucumbiosa differ from their other congeners by having relatively longer posttesticular spaces in their bodies, representing 25-30% and 24-28% of body length respectively, compared with approximately 6-19% in other species.Dos especies nuevas de digéneos pertenecientes a Creptotrema Travassos, Artigas y Pereira, 1928 fueron descritas de ejemplares depositados en la colección de invertebrados del Museo de Historia Natural de Ginebra, Suiza. Creptotrema lamothei n. sp. fue descrita en Ageneiosus brevifilis Valenciennes in Cuvier y Valenciennes, 1840 (Siluriformes: Ageneiosidae, Auchenipterus nuchalis (Spix y Agassiz, 1829 (Siluriformes: Auchenipteridae, y Bryconops melanurus (Bloch, 1794 (Characiformes: Characidae en el río Paraguay, Paraguay. Creptotrema sucumbiosa n. sp. fue descrita de Tetragonopterus argenteus, Cuvier 1816 (Characiformes: Characidae en el río Aquarico, Ecuador. Creptotrema lamothei difiere de sus congéneres por tener testículos con contornos irregulares en contraste con los que presentan contornos enteros. Creptotrema sucumbiosa difiere de

  3. Concepts of keystone species and species importance in ecology

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper discussed the keystone species concept and introduced the typical characteristics of keystone species and their identification in communities or ecosystems. Based on the research of the keystone species, the concept of species importance (SI) was first advanced in this paper. The species importance can be simply understood as the important value of species in the ecosystem, which consists of three indexes: species structural important value (SIV), functional important value (FIV) and dynamical important value (DIV). With the indexes, the evaluation was also made on species importance of arbor trees in the Three-Hardwood forests (Fraxinus mandshurica, Juglans mandshurica, and Phellodendron amurense) ecosystem.

  4. Bounding species distribution models

    Directory of Open Access Journals (Sweden)

    Thomas J. STOHLGREN, Catherine S. JARNEVICH, Wayne E. ESAIAS,Jeffrey T. MORISETTE

    2011-10-01

    Full Text Available Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern. Many investigators now recognize that extrapolations of these models with geographic information systems (GIS might be sensitive to the environmental bounds of the data used in their development, yet there is no recommended best practice for “clamping” model extrapolations. We relied on two commonly used modeling approaches: classification and regression tree (CART and maximum entropy (Maxent models, and we tested a simple alteration of the model extrapolations, bounding extrapolations to the maximum and minimum values of primary environmental predictors, to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States. Findings suggest that multiple models of bounding, and the most conservative bounding of species distribution models, like those presented here, should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 (5: 642–647, 2011].

  5. Management of invasive species

    DEFF Research Database (Denmark)

    Schou, Jesper Sølver; Jensen, Frank

    In this paper, we conduct a number of cost-benefit analyses to clarify whether the establishment of invasive species should be prevented or the damage of such species should be mitigated after introduction. We use the potential establishment of ragweed in Denmark as an empirical case. The main...... impact of the establishment of this invasive species is a substantial increase in the number of allergy cases, which we use as a measure of the physical damage. As valuation methods, we use both the cost-of-illness method and the benefit transfer method to quantify the total gross benefits of the two...... policy actions. Based on the idea of an invasion function, we identify the total and average net benefit under both prevention and mitigation. For both policy actions, the total and average net benefits are significantly positive irrespective of the valuation method used; therefore, both prevention...

  6. Bounding Species Distribution Models

    Science.gov (United States)

    Stohlgren, Thomas J.; Jarnevich, Cahterine S.; Morisette, Jeffrey T.; Esaias, Wayne E.

    2011-01-01

    Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern. Many investigators now recognize that extrapolations of these models with geographic information systems (GIS) might be sensitive to the environmental bounds of the data used in their development, yet there is no recommended best practice for "clamping" model extrapolations. We relied on two commonly used modeling approaches: classification and regression tree (CART) and maximum entropy (Maxent) models, and we tested a simple alteration of the model extrapolations, bounding extrapolations to the maximum and minimum values of primary environmental predictors, to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States. Findings suggest that multiple models of bounding, and the most conservative bounding of species distribution models, like those presented here, should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 (5): 642-647, 2011].

  7. Non-native gobies facilitate the transmission of Bucephalus polymorphus (Trematoda)

    National Research Council Canada - National Science Library

    Ondračková, Markéta; Hudcová, Iveta; Dávidová, Martina; Adámek, Zdeněk; Kašný, Martin; Jurajda, Pavel

    2015-01-01

    .... Recently infection by the trematode Bucephalus polymorphus has increased in several European rivers, being attributed to the introduction of intermediate host species from the Ponto-Caspian region...

  8. A new species of Curvularia

    NARCIS (Netherlands)

    Aa, van der H.A.

    1967-01-01

    Curvularia papendorfii, isolated from South African soil, is described as a new species. This species is characterized by greater overall dimensions than in any of the known species, and a hilum to the spore that is not protuberant at all.

  9. Prices and species diversity

    DEFF Research Database (Denmark)

    Sauer, Johannes

    of biodiversity and the appropriate incorporation in stochastic fron-tier models to achieve more realistic measures of production efficiency. We use the empirical example of tobacco production drawing from as well as affecting species diversity in the surrounding forests. We apply a shadow profit distance....... Based on a biologically defined species diver-sity index we incorporate biodiversity either as a desirable output or biodiversity loss as a detrimental input. Beside quantitative shadow price measures the main contribu-tion of the work is the evidence that parametric scores of environmental efficiency...

  10. Prices and species diversity

    DEFF Research Database (Denmark)

    Sauer, Johannes

    . Based on a biologically defined species diver-sity index we incorporate biodiversity either as a desirable output or biodiversity loss as a detrimental input. Beside quantitative shadow price measures the main contribu-tion of the work is the evidence that parametric scores of environmental efficiency...... of biodiversity and the appropriate incorporation in stochastic fron-tier models to achieve more realistic measures of production efficiency. We use the empirical example of tobacco production drawing from as well as affecting species diversity in the surrounding forests. We apply a shadow profit distance...

  11. Bioterrorism and invasive species.

    Science.gov (United States)

    Chomel, B B; Sun, B

    2010-08-01

    The risk of dispersing invasive species, especially human pathogens, through acts of bioterrorism, cannot be neglected. However, that risk appears quite low in comparison with the risk of dispersing animal pathogens that could dramatically burden the agricultural economy of food animal producing countries, such as Australia and countries in Europe and North and South America. Although it is not directly related to bioterrorism, the intentional release of non-native species, particularly undesired companion animals or wildlife, may also have a major economic impact on the environment and, possibly, on animal and human health, in the case of accidental release of zoonotic agents.

  12. Coevolution of Symbiotic Species

    CERN Document Server

    Leok, B T M

    1996-01-01

    This paper will consider the coevolution of species which are symbiotic in their interaction. In particular, we shall analyse the interaction of squirrels and oak trees, and develop a mathematical framework for determining the coevolutionary equilibrium for consumption and production patterns.

  13. Brachylaima ezohelicis sp. nov. (Trematoda: Brachylaimidae) found from the land snail Ezohelix gainesi, with a note of an unidentified Brachylaima species in Hokkaido, Japan.

    Science.gov (United States)

    Nakao, Minoru; Waki, Tsukasa; Sasaki, Mizuki; Anders, Jason L; Koga, Daisuke; Asakawa, Mitsuhiko

    2017-06-01

    In the Japanese Archipelago, Ezohelix gainesi, a member of bradybaenid land snails, is endemic mainly to the island of Hokkaido. During July to August of 2016, a survey to detect trematode infections from E. gainesi was carried out at a forest city park in Asahikawa, Hokkaido. Systemic infections of the snails with sporocysts containing short-tailed cercariae were found in 5.3% of 94 individuals examined. Furthermore, most of them (90.4%) harbored non-encysted metacercariae within their kidneys. A DNA sequence identification revealed that both of the sporocyst and the metacercaria belong to an unknown species of the family Brachylaimidae. The metacercariae showed a genetic diversity with 6 haplotypes of mitochondrial DNA (mtDNA) even in the limited sampling area. A definitive host of the unknown species could not be determined, although 34 field mice (Apodemus speciosus) and 21 voles (Myodes rufocanus) from the city park were examined for intestinal parasites. To examine the adult stage, the metacercariae were perorally administrated to mice, together with anti-inflammatory treatment with methylprednisolone. Fully matured adult worms were recovered from the intestinal ileum 8 and 14days postinfection. The gravid adults showed typical features of the genus Brachylaima. A morphological and biogeographical evaluation prompted us to propose Brachylaima ezohelicis sp. nov. for the parasite from E. gainesi. The autochthony of the first intermediate host and the spatial heterogeneity of mtDNA suggest that the new species found in the city park is not a recently expanded population of immigrant origin. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Positive feedback in species communities

    NARCIS (Netherlands)

    Gerla, D.J.

    2012-01-01

    Sometimes the eventual population densities in a species community depend on the initial densities or the arrival times of species. If arrival times determine species composition, a priority effect has occurred. Priority effects may occur if the species community exhibits alternative stable states (

  15. The functional biogeography of species

    DEFF Research Database (Denmark)

    Carstensen, D.W.; Dalsgaard, B.; Svenning, J.-C.

    2013-01-01

    between species traits and large-scale species distribution patterns in archipelagos, we use a network approach to classify birds as one of four biogeographical species roles: peripherals, connectors, module hubs, and network hubs. These roles are based upon the position of species within the modular...

  16. Identification of Malassezia species.

    Science.gov (United States)

    Kindo, A J; Sophia, S K C; Kalyani, J; Anandan, S

    2004-01-01

    Malassezia spp. are lipophilic unipolar yeasts recognized as commensals of skin that may be pathogenic under certain conditions. The genus Malassezia now comprises of seven species. This study was aimed at using a simple practical approach to speciate Malassezia yeasts from clinical material. Seventy skin scrapings from patients with pityriasis versicolor infection, positive in 10% potassium hydroxide (KOH), were cultured onto modified Dixon's agar (mDixon's agar) and Sabouraud dextrose agar (SDA) and incubated at 32 degrees C. Speciation was done on the basis of Gram stain morphology, catalase test, and utilization of Tweens. Out of 70 scrapings 48 (68.75%) showed growth on mDixon's agar. The commonest isolate was M. sympodialis (28, 58%) followed by M. globosa (19, 40%) and one isolate was (2%) of M. restricta. M. sympodialis was the commonest species affecting our population and there was no isolation of M. obtusa, M. slooffiae, M. pachydermatis and M. furfur.

  17. Arctic species resilience

    DEFF Research Database (Denmark)

    Mortensen, Lars O.; Forchhammer, Mads C.; Jeppesen, Erik

    and precipitation. Concurrently, phenological change has been recorded in a wide range of plants and animals, with climate change seemingly being the primary driver of these changes. A major concern is whether species and biological systems embrace the plasticity in their phenological responses needed for tracking......The peak of biological activities in Arctic ecosystems is characterized by a relative short and intense period between the start of snowmelt until the onset of frost. Recent climate changes have induced larger seasonal variation in both timing of snowmelt as well as changes mean temperatures...... the predicted increase in climate variability. Whereas species may show relatively high phenological resilience to climate change per se, the resilience of systems may be more constrained by the inherent dependence through consumer-resource interactions across trophic levels. During the last 15 years...

  18. Trichoderma species from China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chu-long; XU Tong

    2004-01-01

    @@ Seventeen species of Trichoderma, isolated from soil or tree bark from China are identified based on morphological and physiological characters, and from their phylogenetic position inferred from parsimony analyses of nucleotide sequences of the internal transcribed spacer regions of the rDNA cluster (ITS1 and 2) and partial sequences of translation elongation factor 1-alpha (tef1) . There were T. citrinoviride, T. longibrachiatum, T. sinensis in section Longibrachiatum, T. atroviride, T.koningii, T. viride, T. asperellum, T. hamatum, T. erinaceum in section Trichoderma, T.harzianum (H.lixii) , T. inhamatum, T. velutinum , T. cerinum , T. strictipile , T. spirale ,T. virens, H. nigrovirens (Trichoderma sp.) in section Pachybasium. Among them four species:T. asperellum , T. velutinum , T. cerinum , T. spirale were reported firstly in China. In addition, two suspected new taxa (Trichoderma spp.) in Trichoderma section were proposed:Trichoderma sp. 1 (ZAUT261, 4, 4A, 15A, 2C), Trichoderma sp. 2 (2B, 5, 7A, 7B, 9A).Trichoderma sp. 1 was similar to T. hamatum , but the temperature optimum for mycelial growth was lower than that of T. hamatum and the species tended to form hemisphaerical pustule with Telatively larger conidia (average length 4.6 μm × 2.8 μm). Trichoderma sp. 2 was distinguished morphologically from related species T. strigosum, T. pubescens, T. erinaceum, T. hamatum and Trichoderma sp. 1 in pustules on CMD without fertile or sterile conidiophore elongation and distinctive phialide shape, the conidiophore branches similar to T. koningii, but the conidia similar to T. viride, subglobose, conspicuously tuberculate.

  19. Introduced Terrestrial Species Richness

    Science.gov (United States)

    These data represent predicted current distributions of all introduced mammals, birds, reptiles, amphibians and butterflies in the Middle-Atlantic region. These data are available for both 8-digit HUCs and EMAP hexagons. The data are species counts for each spatial unit. More information about these resources, including the variables used in this study, may be found here: https://edg.epa.gov/data/Public/ORD/NERL/ReVA/ReVA_Data.zip.

  20. Bounding species distribution models

    Institute of Scientific and Technical Information of China (English)

    Thomas J. STOHLGREN; Catherine S. JARNEVICH; Wayne E. ESAIAS; Jeffrey T. MORISETTE

    2011-01-01

    Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern.Many investigators now recognize that extrapolations of these models with geographic information systems (GIS) might be sensitive to the environmental bounds of the data used in their development,yet there is no recommended best practice for “clamping” model extrapolations.We relied on two commonly used modeling approaches:classification and regression tree (CART) and maximum entropy (Maxent) models,and we tested a simple alteration of the model extrapolations,bounding extrapolations to the maximum and minimum values of primary environmental predictors,to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States.Findings suggest that multiple models of bounding,and the most conservative bounding of species distribution models,like those presented here,should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 (5):642-647,2011].

  1. A first insight into the barcodes for African diplostomids (Digenea: Diplostomidae): brain parasites in Clarias gariepinus (Siluriformes: Clariidae).

    Science.gov (United States)

    Chibwana, Fred D; Blasco-Costa, Isabel; Georgieva, Simona; Hosea, Kenneth M; Nkwengulila, Gamba; Scholz, Tomáš; Kostadinova, Aneta

    2013-07-01

    Diplostomid trematodes comprise a large and diverse group of widespread digeneans whose larval stages are important parasitic pathogens that may exert serious impacts in wild and cultured freshwater fish. However, our understanding of their diversity remains incomplete especially in the tropics. Our study is the first application of a DNA-based approach to diplostomid diversity in the African continent by generating a database linking sequences for the mitochondrial cytochrome c oxidase subunit 1 (cox1) barcode region and ITS1-5.8S-ITS2 rRNA gene cluster for brain-infecting diplostomid metacercariae from the catfish Clarias gariepinus. Analyses of newly-generated partial cox1 sequences for 34 larval isolates of Tylodelphys spp. from Tanzania and Diplostomum spp. from Tanzania and Nigeria revealed three strongly supported reciprocally monophyletic lineages of Tylodelphys spp. and one of an unknown species of Diplostomum. The average intraspecific divergence for the cox1 sequences for each recognised novel lineage was distinctly lower compared with interspecific divergence (0.46-0.75% vs 11.7-14.8%). The phylogenetic hypotheses estimated from Bayesian inference and maximum likelihood analyses of ITS1-5.8S-ITS2 data exhibited congruent strong support for the cox1-derived lineages. Our study thus provides molecular-based evidence for the existence of three distinct brain-infecting species co-occurring in natural populations of C. gariepinus. Based on phylogenetic analyses, we re-allocated Diplostomum mashonenseBeverley-Burton (1963) to the genus Tylodelphys as a new combination. We also generated cox1 and ITS1-5.8S-ITS2 sequences for an unknown species of Diplostomum from another African fish host, Synodontis nigrita.

  2. Platynosomum illiciens (Trematoda: Dicrocoeliidae) in Captive Black-Tufted Marmoset Callithrix penicillata (Primates: Cebidae) from Brazil: A Morphometric Analyses with Taxonomic Comments on Species of Platynosomum from Nonhuman Primates.

    Science.gov (United States)

    Pinto, Hudson A; Mati, Vitor L T; Pujoni, Diego G F; Melo, Alan L

    2017-02-01

    The trematodes belonging to the genus Platynosomum are biliary parasites of birds and mammals (domestic and wildlife) in tropical and subtropical areas of the globe. Despite several reports on platynosomosis in captive nonhuman primates, mainly in South America, the taxonomy of species of Platynosomum that infect these hosts remains confused, and it is not clear whether the species found in cats is the same that infects nonhuman primates. Because a detailed morphological study of Platynosomum from nonhuman primates is lacking, in this study we analyzed specimens of Platynosomum recovered from the biliary system of Callithrix penicillata kept in captivity in an animal facility. The helminths were submitted to morphological and morphometric analyses in a light microscope and measurements of 16 morphological traits were taken. A kernel density estimation (KDE) was used to estimate density distributions of the measurements obtained as well as the occurrence of overlap with the ranges of the measurements known to 2 other species of Platynosomum previously described from South American marmosets, Platynosomum amazonensis and Platynosomum marmoseti. A principal component analysis (PCA) was also performed in order to evaluate the position of each of the 3 species in the multivariate gradient of morphometric measurements. The occurrence of a growth gradient was also evaluated by analysis of correlation between the measurements. Besides a great morphological variability, all specimens obtained from marmosets in this study were identified as Platynosomum illiciens (Braun, 1901). In addition, the published ranges of the measurements of P. amazonensis and P. marmoseti were completely contained within the ranges found in this study as revealed by KDE. The PCA did not show the formation of groups, and the 3 species were distributed along a growth continuum, also corroborated by correlation analysis. Therefore, P. amazonensis and P. marmoseti are here synonymized with P. illiciens

  3. Genomics of Bacillus Species

    Science.gov (United States)

    Økstad, Ole Andreas; Kolstø, Anne-Brit

    Members of the genus Bacillus are rod-shaped spore-forming bacteria belonging to the Firmicutes, the low G+C gram-positive bacteria. The Bacillus genus was first described and classified by Ferdinand Cohn in Cohn (1872), and Bacillus subtilis was defined as the type species (Soule, 1932). Several Bacilli may be linked to opportunistic infections. However, pathogenicity among Bacillus spp. is mainly a feature of bacteria belonging to the Bacillus cereus group, including B. cereus, Bacillus anthracis, and Bacillus thuringiensis. Here we review the genomics of B. cereus group bacteria in relation to their roles as etiological agents of two food poisoning syndromes (emetic and diarrhoeal).

  4. Identification of malassezia species

    Directory of Open Access Journals (Sweden)

    Kindo A

    2004-01-01

    Full Text Available Malassezia spp. are lipophilic unipolar yeasts recognized as commensals of skin that may be pathogenic under certain conditions. The genus Malassezia now comprises of seven species. This study was aimed at using a simple practical approach to speciate Malassezia yeasts from clinical material. Seventy skin scrapings from patients with pityriasis versicolor infection, positive in 10% potassium hydroxide (KOH, were cultured onto modified Dixon′s agar (mDixon′s agar and Sabouraud dextrose agar (SDA and incubated at 32ºC. Speciation was done on the basis of Gram stain morphology, catalase test, and utilization of Tweens. Out of 70 scrapings 48 (68.75% showed growth on mDixon′s agar. The commonest isolate was M. sympodialis (28, 58% followed by M. globosa (19, 40% and one isolate was (2% of M. restricta. M. sympodialis was the commonest species affecting our population and there was no isolation of M. obtusa, M. slooffiae, M. pachydermatis and M. furfur.

  5. Save Our Species: Protecting Endangered Species from Pesticides.

    Science.gov (United States)

    Environmental Protection Agency, Washington, DC.

    This full-size poster profiles 11 wildlife species that are endangered. Color illustrations of animals and plants are accompanied by narrative describing their habitats and reasons for endangerment. The reverse side of the poster contains information on the Endangered Species Act, why protecting endangered and threatened species is important, how…

  6. Endangered Species Act Critical Habitat

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Critical habitat (CH) is designated for the survival and recovery of species listed as threatened or endangered under the Endangered Species Act (ESA). Critical...

  7. New species of Malaysian ferns

    NARCIS (Netherlands)

    Holttum, R.E.

    1962-01-01

    The present paper includes descriptions of several new species of ferns found among recent collections from various parts of Malaysia; also two new combinations of names of species which are of interest on account of their taxonomic history.

  8. The functional biogeography of species

    DEFF Research Database (Denmark)

    Carstensen, D.W.; Dalsgaard, B.; Svenning, J.-C.

    2013-01-01

    Biogeographical systems can be analyzed as networks of species and geographical units. Within such a biogeographical network, individual species may differ fundamentally in their linkage pattern, and therefore hold different topological roles. To advance our understanding of the relationship betw...

  9. Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates South Florida, Ladyfish and Tarpon

    Science.gov (United States)

    1989-07-01

    Fish. 24:321-428. * 15 Manter, H.W. 1947. Digenetic Timbers Conf. Ecol. Anim . Control trematodes of marine fishes. Am. Habitat Manage. 5:5-17. Midl...Contribucion a la morfologia tional Fish. 2:105-112. y organogenesis de los leptocefalos del sabalo Megalops atlanticus Rebins, C.R., R.M. Bailey, C.E. Bond

  10. Timeless standards for species delimitation.

    Science.gov (United States)

    Amorim, Dalton S; Santos, Charles Morphy D; Krell, Frank-Thorsten; Dubois, Alain; Nihei, Silvio S; Oliveira, Otto M P; Pont, Adrian; Song, Hojun; Verdade, Vanessa K; Fachin, Diego A; Klassa, Bruna; Lamas, Carlos José E; Oliveira, Sarah S; Carvalho, Claudio J B De; Mello-Patiu, Cátia A; Hajdu, Eduardo; Couri, Márcia S; Silva, Vera C; Capellari, Renato S; Falaschi, Rafaela L; Feitosa, Rodrigo M; Prendini, Lorenzo; Pombal, José P Jr; Fernández, Fernando; Rocha, Rosana M; Lattke, John E; Caramaschi, Ulisses; Duarte, Marcelo; Marques, Antonio Carlos; Reis, Roberto E; Kurina, Olavi; Takiya, Daniela M; Tavares, Marcos; Fernandes, Daniel Silva; Franco, Francisco Luís; Cuezzo, Fabiana; Paulson, Dennis; Guénard, Benoit; Schlick-Steiner, Birgit C; Arthofer, Wolfgang; Steiner, Florian M; Fisher, Brian L; Johnson, Robert A; Delsinne, Thibaut Dominique; Donoso, David A; Mulieri, Pablo Ricardo; Patitucci, Luciano Damián; Carpenter, James M; Herman, Lee; Grimaldi, David

    2016-07-08

    Recently a new species of bombyliid fly, Marleyimyia xylocopae, was described by Marshall & Evenhuis (2015) based on two photographs taken during fieldwork in the Republic of South Africa. This species has no preserved holotype. The paper generated some buzz, especially among dipterists, because in most cases photographs taken in the field provide insufficient information for properly diagnosing and documenting species of Diptera.

  11. Electrosmog and species conservation

    Energy Technology Data Exchange (ETDEWEB)

    Balmori, Alfonso, E-mail: abalmorimartinez@gmail.com

    2014-10-15

    Despite the widespread use of wireless telephone networks around the world, authorities and researchers have paid little attention to the potential harmful effects of mobile phone radiation on wildlife. This paper briefly reviews the available scientific information on this topic and recommends further studies and specific lines of research to confirm or refute the experimental results to date. Controls must be introduced and technology rendered safe for the environment, particularly, threatened species. - Highlights: • Studies have shown effects in both animals and plants. • Two thirds of the studies reported ecological effects. • There is little research in this area and further research is needed. • The technology must be safe. • Controls should be introduced to mitigate the possible effects.

  12. Insular species swarm goes underground

    DEFF Research Database (Denmark)

    P. S. Reboleira, Ana Sofia; Enghoff, Henrik

    2014-01-01

    Two new species of the genus Cylindroiulus Verhoeff, 1894, C. julesvernei and C. oromii, are described from the subterranean ecosystem of Madeira Island, Portugal. Species are illustrated with photographs and diagrammatic drawings. The new species belong to the Cylindroiulus madeirae......-group, an insular species swarm distributed in the archipelagos of Madeira and the Canary Islands. We discuss the differences between the new species and their relatives and present information on the subterranean environment of Madeira. An updated overview of the subterranean biodiversity of millipedes...

  13. Hebeloma species associated with Cistus.

    Science.gov (United States)

    Eberhardt, Ursula; Beker, Henry J; Vila, Jordi; Vesterholt, Jan; Llimona, Xavier; Gadjieva, Rena

    2009-01-01

    The genus Hebeloma has a number of species highly specific to Cistus and others that occur with several host genera. This paper discusses the species of Hebeloma that appear to be ectomycorrhizal with Cistus, judging from their occurrence when Cistus is the only available host. The previously unknown species H. plesiocistum spec. nov. is described. We also provide a key to the known Hebeloma associates of Cistus. Molecular analyses based on ITS sequence data further illustrate the distinctness of the newly described species and difficulties in the species delimitation with view to H. erumpens. Specific associations with Cistus may have evolved more than once within the genus Hebeloma.

  14. Species of Wadicosa (Araneae, Lycosidae): a new species from Madagascar.

    Science.gov (United States)

    Kronestedt, Torbjörn

    2017-05-10

    Since establishing the wolf spider genus Wadicosa Zyuzin, 1985 (Zyuzin 1985), eleven species have been accepted in it, either by transfer from Lycosa Latreille, 1804 or Pardosa C.L. Koch, 1847 or by original designation (WSC 2017). However, according to Kronestedt (1987), additional species wait to be formally transferred to Wadicosa. The genus is restricted to the Old World, with one species, Wadicosa jocquei Kronestedt, 2015, recently described from Madagascar and surrounding islands.

  15. Native species that can replace exotic species in landscaping

    Directory of Open Access Journals (Sweden)

    Elisabeth Regina Tempel Stumpf

    2015-08-01

    Full Text Available Beyond aesthetics, the contemporary landscaping intends to provide other benefits for humans and environment, especially related to the environmental quality of urban spaces and conservation of the species. A trend in this direction is the reduction in the use of exotic plants in their designs, since, over time, they can become agents of replacement of native flora, as it has occurred in Rio Grande do Sul with many species introduced by settlers. However, the use of exotic species is unjustifiable, because the flora diversity of the Bioma Pampa offers many native species with appropriate features to the ornamental use. The commercial cultivation and the implantation of native species in landscaped areas constitute innovations for plant nurseries and landscapers and can provide a positive reduction in extractivism, contributing to dissemination, exploitation and preservation of native flora, and also decrease the impact of chemical products on environment. So, this work intends to identify native species of Bioma Pampa with features and uses similar to the most used exotic species at Brazilian landscaping. The species were selected from consulting books about native plants of Bioma Pampa and plants used at Brazilian landscaping, considering the similarity on habit and architecture, as well as characteristics of leafs, flowers and/or fruits and environmental conditions of occurrence and cultivation. There were identified 34 native species able to properly replace exotic species commonly used. The results show that many native species of Bioma Pampa have interesting ornamental features to landscape gardening, allowing them to replace exotic species that are traditionally cultivated.

  16. New mite species associated with certain plant species from Guam

    Directory of Open Access Journals (Sweden)

    Gadi V.P. Reddy

    2011-04-01

    Full Text Available Several new mite species have been reported from certain plants from Guam. Most remarkably, the spider mite, Tetranychus marianae (Prostigmata: Tetranychidae and the predatory mite Phytoseius horridus (Mesostigmata: Phytoseiidae (Solanum melongena have been found on eggplant. The noneconomically important species of Brevipalpus californicus(Banks Prostigmata: Tenuipalpidae,Eupodes sp. (Acarina: Eupodidae and predator Cunaxa sp. (Prostigmata: Cunaxidae have been reported on guava (Psidium guajava L.. Also, the non-economically important species Brevipalpus californicus Prostigmata: Tenuipalpidae, Lepidoglyphus destructor (Astigmata: Glycyphagidae and a predator Amblyseius obtusus, species group Amblyseius near lentiginosus (Mesostigmata: Phytoseiidae, have been recorded on cycad (Cycas micronesica.

  17. Ring species as demonstrations of the continuum of species formation

    DEFF Research Database (Denmark)

    Pereira, Ricardo José Do Nascimento; Wake, David B.

    2015-01-01

    In the mid-20th century, Ernst Mayr (1942) and Theodosius Dobzhansky (1958) championed the significance of 'circular overlaps' or 'ring species' as the perfect demonstration of the gradual nature of species formation. As an ancestral species expands its range, wrapping around a geographic barrier...... resulted in restrictive gene flow relative to that observed around the ring, their results suggest that circular overlaps might be more common in nature than currently recognized in the literature. Most importantly, this work shows that the continuum of species formation that Mayr and Dobzhansky praised...

  18. Confronting species distribution model predictions with species functional traits.

    Science.gov (United States)

    Wittmann, Marion E; Barnes, Matthew A; Jerde, Christopher L; Jones, Lisa A; Lodge, David M

    2016-02-01

    Species distribution models are valuable tools in studies of biogeography, ecology, and climate change and have been used to inform conservation and ecosystem management. However, species distribution models typically incorporate only climatic variables and species presence data. Model development or validation rarely considers functional components of species traits or other types of biological data. We implemented a species distribution model (Maxent) to predict global climate habitat suitability for Grass Carp (Ctenopharyngodon idella). We then tested the relationship between the degree of climate habitat suitability predicted by Maxent and the individual growth rates of both wild (N = 17) and stocked (N = 51) Grass Carp populations using correlation analysis. The Grass Carp Maxent model accurately reflected the global occurrence data (AUC = 0.904). Observations of Grass Carp growth rate covered six continents and ranged from 0.19 to 20.1 g day(-1). Species distribution model predictions were correlated (r = 0.5, 95% CI (0.03, 0.79)) with observed growth rates for wild Grass Carp populations but were not correlated (r = -0.26, 95% CI (-0.5, 0.012)) with stocked populations. Further, a review of the literature indicates that the few studies for other species that have previously assessed the relationship between the degree of predicted climate habitat suitability and species functional traits have also discovered significant relationships. Thus, species distribution models may provide inferences beyond just where a species may occur, providing a useful tool to understand the linkage between species distributions and underlying biological mechanisms.

  19. Uncommon Species and Other Features

    Data.gov (United States)

    Vermont Center for Geographic Information — The Vermont Fish and Wildlife Department's Natural Heritage Inventory (NHI) maintains a database of uncommon, rare, threatened and endangered species and natural...

  20. Incorporating Context Dependency of Species Interactions in Species Distribution Models.

    Science.gov (United States)

    Lany, Nina K; Zarnetske, Phoebe L; Gouhier, Tarik C; Menge, Bruce A

    2017-07-01

    Species distribution models typically use correlative approaches that characterize the species-environment relationship using occurrence or abundance data for a single species. However, species distributions are determined by both abiotic conditions and biotic interactions with other species in the community. Therefore, climate change is expected to impact species through direct effects on their physiology and indirect effects propagated through their resources, predators, competitors, or mutualists. Furthermore, the sign and strength of species interactions can change according to abiotic conditions, resulting in context-dependent species interactions that may change across space or with climate change. Here, we incorporated the context dependency of species interactions into a dynamic species distribution model. We developed a multi-species model that uses a time-series of observational survey data to evaluate how abiotic conditions and species interactions affect the dynamics of three rocky intertidal species. The model further distinguishes between the direct effects of abiotic conditions on abundance and the indirect effects propagated through interactions with other species. We apply the model to keystone predation by the sea star Pisaster ochraceus on the mussel Mytilus californianus and the barnacle Balanus glandula in the rocky intertidal zone of the Pacific coast, USA. Our method indicated that biotic interactions between P. ochraceus and B. glandula affected B. glandula dynamics across >1000 km of coastline. Consistent with patterns from keystone predation, the growth rate of B. glandula varied according to the abundance of P. ochraceus in the previous year. The data and the model did not indicate that the strength of keystone predation by P. ochraceus varied with a mean annual upwelling index. Balanus glandula cover increased following years with high phytoplankton abundance measured as mean annual chlorophyll-a. M. californianus exhibited the same

  1. Trematode infections reduce clearance rates and condition in blue mussels

    NARCIS (Netherlands)

    Stier, T.; Drent, J.; Thieltges, D.W.

    2015-01-01

    Suspension feeders are important players in coastal food webs: by filtering particles suspended in the water column and depositing faeces and pseudofaeces in sediments, they mediate the coupling of pelagic primary and benthic secondary production. However, the potential interference of parasite

  2. Inventory of organisms interfering with transmission of a marine trematode

    NARCIS (Netherlands)

    Welsh, J.E.; van der Meer, J.; Brussaard, C.P.D.; Thieltges, D.W.

    2014-01-01

    It has increasingly been recognized that organisms can interfere with parasitic free-living stages, preventing them from infecting their specified host and thus reducing infection levels. This common phenomenon in freshwater and terrestrial systems has been termed the ‘dilution effect’ and, so far,

  3. Inventory of organisms interfering with transmission of a marine trematode

    NARCIS (Netherlands)

    Welsh, J.E.; van der Meer, J.; Brussaard, C.P.D.; Thieltges, D.W.

    2014-01-01

    It has increasingly been recognized that organisms can interfere with parasitic free-living stages, preventing them from infecting their specified host and thus reducing infection levels. This common phenomenon in freshwater and terrestrial systems has been termed the ‘dilution effect’ and, so far,

  4. Intrapopulational distribution of Meiogymnophallus minutus (Digenea, Gymnophallidae) infections in its first and second intermediate host.

    Science.gov (United States)

    Fermer, Jan; Culloty, Sarah C; Kelly, Thomas C; O'Riordan, Ruth M

    2009-10-01

    Host size and age are generally assumed to play a pivotal role in digenean trematode infection patterns, accounting for much of the variation found within intermediate host populations. However, knowledge is based on a limited number of studied host-parasite systems. We investigated the shell length class distribution of Meiogymnophallus minutus infections within populations of the first intermediate host Scrobicularia plana and second intermediate host Cerastoderma edule. Infections occurred very early in the life of the two intermediate hosts. Both prevalence and intensity of infections increased with host shell length and displayed extremely high values amongst large individuals. Whilst metacercarial infection patterns in juvenile C. edule could be best explained by differences in host shell length, in adult cockles, the effect of host age on infection levels prevailed. The microsporidian hyperparasite Unikaryon legeri, occurring in the metacercarial stage of M. minutus, was particularly abundant in aged cockles, strongly influencing infection patterns of the gymnophallid. Our results are consistent with the intrapopulational distribution reported from other digenean trematode parasites. The relative influence of both host size and age and the underlying mechanisms as well as the impact of hyperparasitism on M. minutus infection patterns are discussed.

  5. Contribuição ao conhecimento das espécies do subgênero Lepidapedon (Lepidapedoides Yamaguti 1970: (Trematoda, Lepidapedinae Contribution to the knowledge of the species under the subgenus Lepidapedon (Lepidapedoides Yamaguti, 1970, (Trematoda, Lepidapedinae

    Directory of Open Access Journals (Sweden)

    Sueli P. de Fabio

    1974-01-01

    Full Text Available Os autores, no presente trabalho, fazem um estudo da posição sistemática das espécies do subgênero Lepidapedon (Lepidapedoides Yamaguti, 1970, sendo o mesmo referido pela primeira vez no Brasil. Transferem para este subgênero: L. hancocki Manter, 1940; L. longevesiculum Hafeezullah, 1970 e L. manteri Hafeezullah, 1970. Consideram L. ghanensis Fischthal & Thomas, 1970 sinônimo de L. holocentri Siddiqi & Cable, 1960. Apresentam uma chave de classificação para as espécies pertencentes á Lepidapedon (Lepidapedoides Yamaguti, 1970. Descrevem e figuram L. (L. epinepheli Bravo-Hollis & Manter, 1957 em novo hospedeiro.In this paper the authors discuss the systematical position of the species under Lepidapedon (Lepidapedoides Yamaguti, 1970, as well as refer it for the first time in Brasil. They transfer to this subgenus L. hancocki manter, 1940; L. longevesiculum hafeezullah, 1970 and L. manteri Hafeezullah, 1970. L. (L. ghanensis Fischthal & Thomas, 1970 is considered a synomim of L. (L. holocentri Siddiqi & Cable, 1960. They present a classification key for the species under Lepidapedon (Lepidapedoides Yamaguti, 1970 and a complete description and original drawings of L. (L. epinepheli Bravo-Hollis & Manter, 1957, also refering a new host record for it. The authors disagree about the proposition of the type species of the subgenus, L. (L. holocentri Siddiqi & Cable, 1960, for L. (L. levenseni (Linton, 1907 Manter, 1947 is the former one and has all the representing characters of Lepidapedon (Lepidapedoides. The trematodes were recovered from intestine of Lutjanus jocu (Bloch & Schneider commonly named "Vermelho", from Cabo Frio, Rio de Janeiro State.

  6. Fuzzy species among recombinogenic bacteria

    Directory of Open Access Journals (Sweden)

    Fraser Christophe

    2005-03-01

    Full Text Available Abstract Background It is a matter of ongoing debate whether a universal species concept is possible for bacteria. Indeed, it is not clear whether closely related isolates of bacteria typically form discrete genotypic clusters that can be assigned as species. The most challenging test of whether species can be clearly delineated is provided by analysis of large populations of closely-related, highly recombinogenic, bacteria that colonise the same body site. We have used concatenated sequences of seven house-keeping loci from 770 strains of 11 named Neisseria species, and phylogenetic trees, to investigate whether genotypic clusters can be resolved among these recombinogenic bacteria and, if so, the extent to which they correspond to named species. Results Alleles at individual loci were widely distributed among the named species but this distorting effect of recombination was largely buffered by using concatenated sequences, which resolved clusters corresponding to the three species most numerous in the sample, N. meningitidis, N. lactamica and N. gonorrhoeae. A few isolates arose from the branch that separated N. meningitidis from N. lactamica leading us to describe these species as 'fuzzy'. Conclusion A multilocus approach using large samples of closely related isolates delineates species even in the highly recombinogenic human Neisseria where individual loci are inadequate for the task. This approach should be applied by taxonomists to large samples of other groups of closely-related bacteria, and especially to those where species delineation has historically been difficult, to determine whether genotypic clusters can be delineated, and to guide the definition of species.

  7. Antifungal compounds from Piper species

    Science.gov (United States)

    Piper is a big genus of the plant family Piperaceae, with more than 700 species widely distributed in the tropical and subtropical regions of the world. Some species are used in folk medicine as analgesics, antiseptics, insecticides, and antimicrobials or for the treatment of toothache, haemorrhoid...

  8. Hebeloma species associated with Cistus

    NARCIS (Netherlands)

    Eberhardt, U.; Beker, H.J.; Vila, J.; Vesterholt, J.; Llimona, X.; Gadjieva, R.

    2009-01-01

    The genus Hebeloma has a number of species highly specific to Cistus and others that occur with several host genera. This paper discusses the species of Hebeloma that appear to be ectomycorrhizal with Cistus, judging from their occurrence when Cistus is the only available host. The previously

  9. The Colletotrichum gigasporum species complex

    NARCIS (Netherlands)

    Liu, F.; Cai, L.; Crous, P.W.; Damm, U.

    2014-01-01

    In a preliminary analysis, 21 Colletotrichum strains with large conidia preserved in the CBS culture collection clustered with a recently described species, C. gigasporum, forming a clade distinct from other currently known Colletotrichum species complexes. Multi-locus phylogenetic analyses (ITS,

  10. A new species of Arius

    NARCIS (Netherlands)

    Popta, C.M.L.

    1900-01-01

    Among some fishes, forwarded by the late Dr. Bleeker to the Leyden Museum, I came across four specimens evidently belonging to the genus Arius, differing however from all known species of that genus. They therefore represent a new species, which I now describe under the name of Arius Bleekeri in hon

  11. Humans as a Hyperkeystone Species.

    Science.gov (United States)

    Worm, Boris; Paine, Robert T

    2016-08-01

    Ecologists have identified numerous keystone species, defined as organisms that have outsized ecological impacts relative to their biomass. Here we identify human beings as a higher-order or 'hyperkeystone' species that drives complex interaction chains by affecting other keystone actors across different habitats. Strong indirect effects and a global reach further characterize these interactions and amplify the impacts of human activities on diverse ecosystems, from oceans to forests. We require better understanding of hyperkeystone interaction chains most urgently, especially for marine species and terrestrial large carnivores, which experience relatively higher exploitation rates than other species. This requires innovative approaches that integrate the study of human behavior with food-web theory, and which might provide surprising new insights into the complex ecology of our own species.

  12. IDENTIFICATION OF RESPIRATORY AND GASTROINTESTINAL PARASITES OF THREE SPECIES OF PINNIPEDS (ARCTOCEPHALUS AUSTRALIS, ARCTOCEPHALUS GAZELLA, AND OTARIA FLAVESCENS) IN SOUTHERN BRAZIL.

    Science.gov (United States)

    Jacobus, Kristy; Marigo, Juliana; Gastal, Silvia Bainy; Taniwaki, Sueli Akemi; Ruoppolo, Valeria; Catão-Dias, José Luiz; Tseng, Florina

    2016-03-01

    In order to improve understanding of parasitism in South American pinnipeds, respiratory and gastrointestinal samples were collected from 12 Arctocephalus australis (South American fur seal), one Arctocephalus gazella (Antarctic fur seal), and one Otaria flavescens (South American sea lion). Ova and larvae were microscopically identified from fecal samples and respiratory secretions collected from live A. australis undergoing rehabilitation at Centro de Recuperação de Animais Marinhos (CRAM-FURG) in Rio Grande, Rio Grande do Sul, Brazil during June-July 2012. Adult parasites were collected from the lungs and gastrointestinal tracts of animals that died while undergoing treatment or were found dead along the southern Brazil coast. Parasites were identified by polymerase chain reaction and DNA sequencing, microscopic examination, comparison with keys, and histologic examination of tissues. Lung parasites of the Parafilaroides genus (Metastrongyloidea, Filaroididae) were identified at necropsy in both A. australis and A. gazella and gastrointestinal parasites were found in all three species of pinniped studied. Gastrointestinal parasites identified in A. australis included the nematodes Contracaecum sp. and Pseudoterranova cattani, the cestodes Adenocephalus pacificus (previously Diphyllobothrium pacificum), one from the Tetrabothridae family and one undetermined, and the acanthocephalans Corynosoma sp. and Bolbosoma sp.; from A. gazella the nematode Contracaecum sp. and the acanthocephalan Corynosoma sp.; and from O. flavescens the acanthocephalan Corynosoma sp. Ova from fecal samples from A. australis represent ascarid nematodes, Parafilaroides sp., Adenocephalus pacificus, acanthocephalans, and an egg determined either to be a trematode or pseuophyllidean cestode. With limited information surrounding parasitism, these findings are an important contribution to knowledge of the health of Southern Hemisphere pinnipeds.

  13. Species delimitation and global biosecurity.

    Science.gov (United States)

    Boykin, Laura M; Armstrong, Karen F; Kubatko, Laura; De Barro, Paul

    2012-01-01

    Species delimitation directly impacts on global biosecurity. It is a critical element in the decisions made by national governments in regard to the flow of trade and to the biosecurity measures imposed to protect countries from the threat of invasive species. Here we outline a novel approach to species delimitation, "tip to root", for two highly invasive insect pests, Bemisia tabaci (sweetpotato whitefly) and Lymantria dispar (Asian gypsy moth). Both species are of concern to biosecurity, but illustrate the extremes of phylogenetic resolution that present the most complex delimitation issues for biosecurity; B. tabaci having extremely high intra-specific genetic variability and L. dispar composed of relatively indistinct subspecies. This study tests a series of analytical options to determine their applicability as tools to provide more rigorous species delimitation measures and consequently more defensible species assignments and identification of unknowns for biosecurity. Data from established DNA barcode datasets (COI), which are becoming increasingly considered for adoption in biosecurity, were used here as an example. The analytical approaches included the commonly used Kimura two-parameter (K2P) inter-species distance plus four more stringent measures of taxon distinctiveness, (1) Rosenberg's reciprocal monophyly, (P(AB)),1 (2) Rodrigo's (P(randomly distinct)),2 (3) genealogical sorting index, (gsi),3 and (4) General mixed Yule-coalescent (GMYC).4,5 For both insect datasets, a comparative analysis of the methods revealed that the K2P distance method does not capture the same level of species distinctiveness revealed by the other three measures; in B. tabaci there are more distinct groups than previously identified using the K2P distances and for L. dipsar far less variation is apparent within the predefined subspecies. A consensus for the results from P(AB), P(randomly distinct) and gsi offers greater statistical confidence as to where genetic limits might

  14. Meiofaunal cryptic species challenge species delimitation: the case of the Monocelis lineata (Platyhelminthes: Proseriata) species complex

    NARCIS (Netherlands)

    Scarpa, F.; Cossu, P.; Lai, T.; Sanna, D.; Curini-Galletti, M.; Casu, M.

    2016-01-01

    Given the pending biodiversity crisis, species delimitation is a critically important task in conservation biology, but its efficacy based on single lines of evidence has been questioned as it may not accurately reflect species limits and relationships. Hence, the use of multiple lines of evidence

  15. Species recognition and cryptic species in the Tuber indicum complex.

    Directory of Open Access Journals (Sweden)

    Juan Chen

    Full Text Available Morphological delimitation of Asian black truffles, including Tuber himalayense, T. indicum, T. sinense, T. pseudohimalayense, T. formosanum and T. pseudoexcavatum, has remained problematic and even phylogenetic analyses have been controversial. In this study, we combined five years of field investigation in China with morphological study and DNA sequences analyses (ITS, LSU and β-tubulin of 131 Tuber specimens to show that T. pseudohimalayense and T. pseudoexcavatum are the same species. T. formosanum is a separate species based on its host plants and geographic distribution, combined with minor morphological difference from T. indicum. T. sinense should be treated as a synonym of T. indicum. Our results demonstrate that the present T. indicum, a single described morphological species, should include at least two separate phylogenetic species. These findings are of high importance for truffle taxonomy and reveal and preserve the richness of truffle diversity.

  16. Molecular characterisation of Brucella species.

    Science.gov (United States)

    Scholz, H C; Vergnaud, G

    2013-04-01

    The genus Brucella (Mayer and Shaw, 1920) currently consists often species with validly published names. Within most species further differentiation into biovars exists. Genetically, all Brucella species are highly related to each other, exhibiting sequence similarity values of 98% to 100% in aligned regions (core genome). The population structure is clonal. Despite this close genetic relatedness, the various species can be clearly distinguished from each other by application of high-resolution molecular typing tools, in addition to assessment of phenotype and host preference. Accurate species delineation can be achieved by conventional multiplex polymerase chain reaction (PCR), single nucleotide polymorphism (SNP) analysis and multilocus sequence typing (MLST) or multilocus sequence analysis (MLSA). The last is also suitable for phylogenetic reconstructions, owing to the highly clonal evolution of the different species. Highly discriminatory multilocus variable number of tandem repeats (VNTR) analysis (MLVA) allows both species delineation and differentiation of individual isolates and thus represents a perfect first-line toolfor molecular epidemiological studies within outbreak investigations. More recently,whole genome sequencing (WGS)and the resulting global genome-wide SNP analysis have become available. These novel approaches should help in further understanding the evolution, host specificity and pathogenicity of the genus Brucella.

  17. Trichoderma species collected from Iran

    Institute of Scientific and Technical Information of China (English)

    Doostmorad Zafari

    2004-01-01

    @@ In order to identify Trichoderma species isolated from Iran, Trichoderma selective media and malt extract agar (MEA) were used to isolate Trichoderma species from the soil samples. All the cultures were purified on 2% water agar by hyphal tip method prior to morphological examination.Morphological observations were carried out on the cultures grown on 2% MEA and oat meal agar at 20℃ under ambient laboratory conditions. Macroscopic features of colony and microscopic features of conidiophore, phialid and conidium including position of phialids on conidiophore and shape and size of phialids and conidia were studied and recorded 3-5 days after inoculation. Out of 36 tested isolates, using morphological features and molecular data obtained from ITS1, ITS2 and 5.8S regions fourteen species were identified as follow: T. atroviride, T. ghanense, T. spirale, T. erinaceum, T. citrinoviride, T. saturnisporum,T. longibrachiatum , T. hamatum , T. harzianum, T. inhamatum , T. tomentosum , T.virens, T. asperellum, T. koningii. Among the species T. harzianum and T. virens isolates were the most frequent species. In addition of the mentioned species two Tichoderma sp. were collected from walnut rhizospher that they are not fit to any described species so far. Although one of them are T. brevicumpactum introduced informally.

  18. Molecular Typing of Nocardia Species

    Directory of Open Access Journals (Sweden)

    Seyyed Saeed Eshraghi

    2012-03-01

    Full Text Available Identification of clinically significant Nocardia species is essential for the definitive diagnosis, predict antimicrobial susceptibility, epidemiological purposes, and for an effective treatment. Conventional identification of Nocardia species in routine medical laboratories which is based on phenotypic (cellular morphology, colonial characteristics, biochemical and enzymatic profiles, and chemotaxonomic characteristics is often laborious, and time-consuming. The procedure requires expertise, and newer species can be difficult to differentiate with accuracy from other related species. Alternative methods of identification, such as high performance liquid chromatography (HPLC and molecular biology techniques allow a better characterization of species. The taxonomy of the genus Nocardia has been dramatically been revised during the last decade and more than 30 valid human clinical significance species of Nocardia have been reported. The use of molecular approaches, including 16S rRNA gene sequencing, restriction fragment length polymorphism (RFLP or PCR restriction endonuclease analysis has been the focus of recent investigations to distinguish the isolates of Nocardia from other actinomycetes genera. The methods have revolutionized the characterization of the Nocardiae by providing rapid, sensitive, and accurate identification procedures. The present review describes the currently known medically important pathogenic species of Nocardia.

  19. Cluster Analysis of Ranunculus Species

    Directory of Open Access Journals (Sweden)

    SURANTO

    2002-01-01

    Full Text Available The aim of the experiment was to examine whether the morphological characters of eleven species of Ranunculus collected from a number of populations were in agreement with the genetic data (isozyme. The method used in this study was polyacrilamide gel electrophoresis using peroxides, estarase, malate dehydrogenase, and acid phosphatase enzymes. The results showed that cluster analysis based on isozyme data have given a good support to classification of eleven species based on morphological groups. This study concluded that in certain species each morphological variation was profit to be genetically based.

  20. Species concepts in Calonectria (Cylindrocladium)

    NARCIS (Netherlands)

    Lombard, L.; Crous, P.W.; Wingfield, B.D.; Wingfield, M.J.

    2010-01-01

    Species of Calonectria and their Cylindrocladium anamorphs are important plant pathogens worldwide. At present 52 Cylindrocladium spp. and 37 Calonectria spp. are recognised based on sexual compatibility, morphology and phylogenetic inference. The polyphasic approach of integrating Biological, Morph

  1. Evolution of mutualism between species

    Energy Technology Data Exchange (ETDEWEB)

    Post, W.M.; Travis, C.C.; DeAngelis, D.L.

    1980-01-01

    Recent theoretical work on mutualism, the interaction between species populations that is mutually beneficial, is reviewed. Several ecological facts that should be addressed in the construction of dynamic models for mutualism are examined. Basic terminology is clarified. (PSB)

  2. Achromobacter species in cystic fibrosis

    DEFF Research Database (Denmark)

    Hansen, C R; Pressler, T; Ridderberg, W;

    2013-01-01

    Achromobacter species leads to chronic infection in an increasing number of CF patients. We report 2 cases of Achromobacter ruhlandii cross-infection between patients after well-described indirect contact....

  3. Malassezia Species and Pityriasis Versicolor

    National Research Council Canada - National Science Library

    Rodoplu, Gulin

    2016-01-01

    Malassezia species are found in part of the normal human cutaneous commensal flora, however it has been known for many years that the Malassezia yeasts are associated with a number of different human...

  4. Phenotypic Plasticity and Species Coexistence.

    Science.gov (United States)

    Turcotte, Martin M; Levine, Jonathan M

    2016-10-01

    Ecologists are increasingly interested in predicting how intraspecific variation and changing trait values impact species interactions and community composition. For many traits, much of this variation is caused by phenotypic plasticity, and thus the impact of plasticity on species coexistence deserves robust quantification. Partly due to a lack of sound theoretical expectations, empirical studies make contradictory claims regarding plasticity effects on coexistence. Our critical review of this literature, framed in modern coexistence theory, reveals that plasticity affects species interactions in ways that could impact stabilizing niche differences and competitive asymmetries. However, almost no study integrates these measures to quantify the net effect of plasticity on species coexistence. To address this challenge, we outline novel empirical approaches grounded in modern theory.

  5. Phase Two Protected Species Valuation

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Nonmarket valuation research has produced economic value estimates for a variety of threatened, endangered, and rare species around the world. Although over 40 value...

  6. Phase One Protected Species Valuation

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Nonmarket valuation research has produced economic value estimates for a variety of threatened, endangered, and rare species around the world. Although over 40 value...

  7. Some species tolerate ocean acidification

    Science.gov (United States)

    Balcerak, Ernie

    2011-12-01

    Increasing carbon dioxide levels lead to rising ocean acidity, which can harm corals and many other species of ocean life. Acidification causes calcium carbonate, which corals usually need to build skeletons, to dissolve. “Every day, ocean acidification is taking up the weight of 6 million midsize cars' worth of carbon, said Nina Keul, a graduate student at the Alfred Wegener Institute for Polar and Marine Research in Germany during a 7 December press conference at the AGU Fall Meeting. Somewhat surprising, though, is that some species are more tolerant of acidic conditions than scientists had expected. For instance, Keul exposed a species of foraminifera, Ammonia tepida, to seawater with varying acidity and varying carbonate ion concentrations. Previous studies had found that foraminifera growth declined with decreasing carbonate levels, but Keul's foraminifera continued to grow in the acidic conditions. She said that the mechanism that allows this species to tolerate the low carbonate conditions is as yet unknown.

  8. The Candida Pathogenic Species Complex

    Science.gov (United States)

    Turner, Siobhán A.; Butler, Geraldine

    2014-01-01

    Candida species are the most common causes of fungal infection. Approximately 90% of infections are caused by five species: Candida albicans, Candida glabrata, Candida tropicalis, Candida parapsilosis, and Candida krusei. Three (C. albicans, C. tropicalis, and C. parapsilosis) belong to the CTG clade, in which the CTG codon is translated as serine and not leucine. C. albicans remains the most commonly isolated but is decreasing relative to the other species. The increasing incidence of C. glabrata is related to its reduced susceptibility to azole drugs. Genome analysis suggests that virulence in the CTG clade is associated with expansion of gene families, particularly of cell wall genes. Similar independent processes took place in the C. glabrata species group. Gene loss and expansion in an ancestor of C. glabrata may have resulted in preadaptations that enabled pathogenicity. PMID:25183855

  9. Infrared spectra of mineral species

    CERN Document Server

    Chukanov, Nikita V

    2014-01-01

    This book details more than 3,000 IR spectra of more than 2,000 mineral species collected during last 30 years. It features full descriptions and analytical data of each sample for which IR spectrum was obtained.

  10. The atlas of endangered species

    National Research Council Canada - National Science Library

    Mackay, R

    2009-01-01

    Vividly illustrated with full-color maps and detailed graphics, The Atlas of Endangered Species catalogs the inhabitants of a wide variety of ecosystems, including forests, mangroves, and coral reefs...

  11. Charcoal anatomy of forest species

    OpenAIRE

    Graciela Inés Bolzon de Muñiz; Silvana Nisgoski; Felipe Zatt Shardosin; Ramiro Faria França

    2012-01-01

    Vegetal charcoal retains the anatomical structure of the wood and may permit its botanical identification, which depends on species characteristics, the charcoal fragments size and preservation state. Anatomical characterization of ten forest species charcoal was done envisaging the identification and control of illegal charcoal. Differences between gymnosperms and angiosperms are evident in carbonized wood. Vessel diameter was statistically different between wood and charcoal in Vatairea gui...

  12. Echinacea species of medicinal use

    Directory of Open Access Journals (Sweden)

    Leon Sorin MUNTEAN

    1998-08-01

    Full Text Available Echinacea species come from North America. Preparations of Echinacea pallida Nutt. and Echinacea purpurea (L. Moench are used in healing many diseases owing to their immunostimulative, antivirus and bacteria, scarifying and anti-inflammatory properties. Echinacea pallida Nutt. displays tap root, linear spear-shaped leaves. Seedling plantation with both species is performed in May and spacing of 50 cm between rows and 30 cm between plants per row. Harvest takes place in the 2-nd year of flowering.

  13. Collective behaviour across animal species

    Science.gov (United States)

    Delellis, Pietro; Polverino, Giovanni; Ustuner, Gozde; Abaid, Nicole; Macrì, Simone; Bollt, Erik M.; Porfiri, Maurizio

    2014-01-01

    We posit a new geometric perspective to define, detect, and classify inherent patterns of collective behaviour across a variety of animal species. We show that machine learning techniques, and specifically the isometric mapping algorithm, allow the identification and interpretation of different types of collective behaviour in five social animal species. These results offer a first glimpse at the transformative potential of machine learning for ethology, similar to its impact on robotics, where it enabled robots to recognize objects and navigate the environment.

  14. Survey protocol for invasive species

    OpenAIRE

    Menza, Charles

    2009-01-01

    This protocol was developed by the Biogeography Branch of NOAA’s Center for Coastal Monitoring and Assessment to support invasive species research by the Papahānaumokuākea Marine National Monument. The protocol’s objective is to detect Carijoa riisei and Hypnea musciformis in deepwater habitats using visual surveys by technical divers. Note: This protocol is designed to detect the presence or absence of invasive species. A distinct protocol is required to collect information on abundance ...

  15. Detecting brucella species in Ecuador

    OpenAIRE

    Luna Jarrín, Ligia Elizabeth

    2015-01-01

    Brucelosis is an emerging zoonotic disease in many countries around the world. There are some reports of Brucella abortus infections in cattle and humans in Ecuador, nevertheless, other Brucella species have not been identified. This study was designed to identify circulating Brucella species in 300 goat samples and one canine fetus from 8 different provinces of the highland Andes of the country. The results showed isolates from Brucella melitensis, Brucella suis, Brucella abortus y Brucella ...

  16. Species Egalitarianism and the Environment

    Directory of Open Access Journals (Sweden)

    Kristin Tiili

    2014-06-01

    Full Text Available A general anthropocentric view of the human species affects the environment and is a major contributing factor in the environmental crisis we are currently facing. A species egalitarian society would have positive effects on the crisis, and particularly in regards to short term goals of decreasing greenhouse gases in the atmosphere. Additionally it would increase the quality of life and alleviate the suffering of countless beings, nonhuman animals and humans alike.

  17. Collective behaviour across animal species.

    Science.gov (United States)

    DeLellis, Pietro; Polverino, Giovanni; Ustuner, Gozde; Abaid, Nicole; Macrì, Simone; Bollt, Erik M; Porfiri, Maurizio

    2014-01-16

    We posit a new geometric perspective to define, detect, and classify inherent patterns of collective behaviour across a variety of animal species. We show that machine learning techniques, and specifically the isometric mapping algorithm, allow the identification and interpretation of different types of collective behaviour in five social animal species. These results offer a first glimpse at the transformative potential of machine learning for ethology, similar to its impact on robotics, where it enabled robots to recognize objects and navigate the environment.

  18. Thromboelastography in Selected Avian Species.

    Science.gov (United States)

    Strindberg, Sophie; Nielsen, Tenna W; Ribeiro, Ângela M; Wiinberg, Bo; Kristensen, Annemarie T; Bertelsen, Mads F

    2015-12-01

    Currently available assay methods and reagents are not optimized for evaluating avian hemostasis; therefore, assessing avian coagulopathies is challenging. Recently, thromboelastography (TEG), which measures the viscoelastic properties of blood, has been used clinically in mammalian species to diagnose and characterize hemostatic disorders. To evaluate TEG in healthy individuals of 6 avian species, we modified existing mammalian TEG protocols to allow analysis of citrated, avian whole-blood samples collected from scarlet ibis (Eudocimus ruber) (n = 13), American flamingos ( Phoenicopterus ruber ) (n = 13), helmeted Guinea fowl ( Numida meleagris ) (n = 12), Amazon parrots (Amazona species) (n = 9), Humboldt penguins ( Spheniscus humboldti ) (n = 6), and domestic chickens (n = 16). Activated partial thromboplastin time, prothrombin time, and fibrinogen were measured as a means of comparison. Regardless of the mode of activation, clot formation in the species studied was markedly delayed compared with mammals. Because of prolonged reaction time (14.7-52.7 minutes) with kaolin and diluted tissue factor, undiluted human tissue factor was used in all avian samples because it provided the shortest reaction time. Species differed significantly in reaction time (P = .007), clotting rate (P < .001), rate of clot formation (α angle; P < .001), and maximum amplitude (P < .001) values, indicating that species-specific reference intervals are necessary. Based on these results, TEG with specific reference intervals could prove useful in evaluating avian hemostatic disorders.

  19. Terrestrial animals as invasive species and as species at risk from invasions

    Science.gov (United States)

    Deborah M. Finch; Dean Pearson; Joseph Wunderle; Wayne Arendt

    2010-01-01

    Including terrestrial animal species in the invasive species strategy plan is an important step in invasive species management. Invasions by nonindigenous species threaten nearly 50 percent of imperiled native species in the United States and are the Nation's second leading cause of species endangerment. Invasion and conversion of native habitats by exotic species...

  20. New Helicobacter species in humans.

    Science.gov (United States)

    Andersen, L P

    2001-01-01

    During the last decade several new Helicobacter species have been isolated from human gastric mucosa, fecal samples, liver, and gallbladder. Gastric corkscrew-shaped Helicobacter species: H. heilmannii is usually seen in the gastric foveolae in 0.2-0.6% of histological sections from the gastric mucosa of patients with dyspepsia in Western Europe, but it has only been cultured once. It is genetically and morphologically closely related to H. bizzozeronii and H. salmonis which are common in dogs and cats. It causes constantly active chronic gastritis and is regularly associated with peptic ulcer. Intestinal Helicobacter species: H. cinaedi, H. fennelliae, H. pullorum, H. westmeadii, H. canadensis, and 'H. rappini' have been isolated from patients with enteritis and proctitis. H. fennelliae, H. cinaedi, H. westmeadii, and 'H. rappini' have been isolated also from patients with septicemia. Studies indicate that H. cinaedi is transmitted from hamsters and that H. pullorum is common in chickens. 'H. rappini' has been isolated from sheep, dogs, and mice, whereas no animal reservoir has been found for H. fennelliae. Except for the cases of septicemia, none of these Helicobacter species have yet been proven to cause human disease, but they are suspected to play a role in inflammatory bowel diseases. Hepatobiliary Helicobacter species include several Helicobacter species isolated from bile and liver of animals, but only H. bilis has been isolated from the human gallbladder and H. pylori from the human liver. H. bilis has been isolated from dogs, cats, mice, and rats. Nonpylori Helicobacter species are usually difficult to culture and may be more frequently causes of human disease than realized today.

  1. Xiphinema krugi, Species Complex or Complex of Cryptic Species?

    Science.gov (United States)

    Oliveira, Claudio M G; Ferraz, Luiz C C B; Neilson, Roy

    2006-12-01

    Fourteen morphologically putative populations of X. krugi were clearly separated into four different profiles by RFLP analysis (Alu I and Hinf I), sequencing of the ITS-1 region, and subsequent Maximum Likelihood phylogenetic analyses. These four profiles were further supported by a principal component analysis of morphometric characters that yielded four taxonomic clusters matching those produced by the molecular data. Sequence homology was greater amongst populations that represented the same RFLP profile than between profiles and similar both between representative populations of the RFLP profiles and putative closely related Xiphinema species. This study suggests that X. krugi is a potential species complex comprised of at least four distinct genotypes.

  2. Malassezia Species and Pityriasis Versicolor

    Directory of Open Access Journals (Sweden)

    Gulin Rodoplu

    2016-01-01

    Full Text Available Malassezia species are found in part of the normal human cutaneous commensal flora, however it has been known for many years that the Malassezia yeasts are associated with a number of different human diseases ranging from pityriasis versicolor to seborrhoeic dermatitis. In addition, since the 1980s, they have been reported as causing opportunistic systemic infections. The taxonomy of Malassezia spp. has recently been modified to include 13 obligatorily lipophilic species, plus one non-obligatorily lipophilic species, which only rarely colonizes human hosts and currently the genus consist 14 species as M. furfur, M. pachydermatis, M. sympodialis, M. globosa, M. obtusa, M. slooffiae, M. restricta, M. dermatis, M. japonica, M. nana, M. yamatoensis, M. caprae, M. equina, M. cuniculi. Fastidious growth requirements of Malassezia yeasts defied the initial attempts to culture these organisms and their true identification and the relationship between different species only became apparent with the application of modern molecular techniques. The causative fungus is seen especially in such seborrheic areas as the scalp, face, trunk and upper back. Under the influence of various exogenous or endogenous predisposing factors, these yeasts change from the blastospore form to the mycelial form and become pathogenic. Diagnosis of pityriasis versicolor which is caused by Malassezia species is generally easy and lies on the basis of its clinical appearance and can be confirmed by mycological examination. The diagnosisis is mainly based on direct examination with potassium hydroxide (KOH and demonstration that represents pseudohyphae and blastoconidia as the typical %u201Cspaghetti and meatballs%u201D pattern. Characteristic features of the genus Malassezia include a distinctive morphology and an affinity for lipids in culture. Culture is necessary to recover the infecting strain, especially for epidemiologic purposes and also to test its antifungal susceptibility

  3. Microphallus fonti sp. n. (Digenea: Microphaliidae from the red swamp crawfish in southern United States

    Directory of Open Access Journals (Sweden)

    Robin M. Overstreet

    1992-01-01

    Full Text Available A new species of digenean, Microphallus fonti, is described from the red swamp crawfish in Lousiania, U.S.A. It has a small pharynx and a rudimentary gut like M. opacus and a possibly related species from crayfishes, but it differs from them by its relatively large male copulatory papilla and a conspicuous metraterm.

  4. Molecular epidemiology of Fonsecaea species.

    Science.gov (United States)

    Najafzadeh, Mohammad Javad; Sun, Jiufeng; Vicente, Vania A; Klaassen, Corne H W; Bonifaz, Alexandro; Gerrits van den Ende, A H G; Menken, Steph B J; de Hoog, G Sybren

    2011-03-01

    To assess population diversities among 81 strains of fungi in the genus Fonsecaea that had been identified down to species level, we applied amplified fragment-length polymorphism (AFLP) technology and sequenced the internal transcribed spacer regions and the partial cell division cycle, beta-tubulin, and actin genes. Many species of the genus Fonsecaea cause human chromoblastomycosis. Strains originated from a global sampling of clinical and environmental sources in the Western Hemisphere, Asia, Africa, and Europe. According to AFLP fingerprinting, Fonsecaea isolates clustered in 5 groups corresponding with F. pedrosoi, F. monophora, and F. nubica: the latter 2 species each comprised 2 groups, and F. pedrosoi appeared to be of monophyletic origin. F. pedrosoi was found nearly exclusively in Central and South America. F. monophora and F. nubica were distributed worldwide, but both showed substantial geographic structuring. Clinical cases outside areas where Fonsecaea is endemic were probably distributed by human migration.

  5. Habitat association of Klebsiella species.

    Science.gov (United States)

    Bagley, S T

    1985-02-01

    The genus Klebsiella is seemingly ubiquitous in terms of its habitat associations. Klebsiella is a common opportunistic pathogen for humans and other animals, as well as being resident or transient flora (particularly in the gastrointestinal tract). Other habitats include sewage, drinking water, soils, surface waters, industrial effluents, and vegetation. Until recently, almost all these Klebsiella have been identified as one species, ie, K. pneumoniae. However, phenotypic and genotypic studies have shown that "K. pneumoniae" actually consists of at least four species, all with distinct characteristics and habitats. General habitat associations of Klebsiella species are as follows: K. pneumoniae--humans, animals, sewage, and polluted waters and soils; K. oxytoca--frequent association with most habitats; K. terrigena--unpolluted surface waters and soils, drinking water, and vegetation; K. planticola--sewage, polluted surface waters, soils, and vegetation; and K. ozaenae/K. rhinoscleromatis--infrequently detected (primarily with humans).

  6. Tiarosporella species: Distribution and significance

    Directory of Open Access Journals (Sweden)

    Karadžić Dragan

    2003-01-01

    Full Text Available The genus Tiarosporella consists of eight species of which four occur on conifers. These fungi differ in conidial size and in the form of appendages that occur on the distal end of the conidia (pycnospore. In Europe only the two species have been recorded. T. parca occurs on the species of the genus Picea (P. abies and P. omorika, while T. durmitorensis infests fir (Abies alba. T. parca can be considered, as an endophyte, and it sporulates only when the needles die due to a stress or old age. T. durmitorensis is a very aggressive pathogen colonizing fir needles of all ages. Together with other fungi, it leads to tree death. So far, T. durmitotensis has been found only in European silver fir stands in the National Park "Durmitor" and in the National Park "Biogradska Gora".

  7. Molecular Epidemiology of Fonsecaea Species

    Science.gov (United States)

    Najafzadeh, Mohammad Javad; Sun, Jiufeng; Vicente, Vania A.; Klaassen, Corne H.W.; Bonifaz, Alexandro; van den Ende, A.H.G. Gerrits; Menken, Steph B.J.

    2011-01-01

    To assess population diversities among 81 strains of fungi in the genus Fonsecaea that had been identified down to species level, we applied amplified fragment-length polymorphism (AFLP) technology and sequenced the internal transcribed spacer regions and the partial cell division cycle, β-tubulin, and actin genes. Many species of the genus Fonsecaea cause human chromoblastomycosis. Strains originated from a global sampling of clinical and environmental sources in the Western Hemisphere, Asia, Africa, and Europe. According to AFLP fingerprinting, Fonsecaea isolates clustered in 5 groups corresponding with F. pedrosoi, F. monophora, and F. nubica: the latter 2 species each comprised 2 groups, and F. pedrosoi appeared to be of monophyletic origin. F. pedrosoi was found nearly exclusively in Central and South America. F. monophora and F. nubica were distributed worldwide, but both showed substantial geographic structuring. Clinical cases outside areas where Fonsecaea is endemic were probably distributed by human migration. PMID:21392438

  8. Scandinavian Oncophorus (Bryopsida, Oncophoraceae: species, cryptic species, and intraspecific variation

    Directory of Open Access Journals (Sweden)

    Lars Hedenäs

    2017-05-01

    Full Text Available Scandinavian members of the acrocarpous moss genus Oncophorus were revised after field observations had suggested unrecognized diversity. Based on molecular (nuclear: internal transcribed spacers 1 and 2, ITS; plastid: trnGUCC G2 intron, trnG, rps4 gene + trnS-rps4 spacer, rps4 and morphological evidence, four morphologically distinguishable species are recognized, Oncophorus elongatus (I.Hagen Hedenäs, O. integerrimus Hedenäs sp. nov. (syn. O. virens var. elongatus Limpr., O. virens (Hedw. Brid., and O. wahlenbergii Brid. (O. sardous Herzog, syn. nov.. Oncophorus elongatus was earlier recognized, but much of its variation was hidden within O. wahlenbergii. Its circumscription is here expanded to include plants with long leaves having mostly denticulate or sharply denticulate upper margins and with long and narrow marginal cells in the basal portion of the sheathing leaf lamina. The new species O. integerrimus sp. nov. differs from O. virens in having more loosely incurved leaves and entire or almost entire upper leaf margins. Besides these characters, the species in the respective pairs differ in quantitative features of the leaf lamina cells. Several cryptic entities were found, in several cases as molecularly distinct as some of the morphologically recognizable species, and phylogeographic structure is present within O. elongatus and O. virens.

  9. Community composition and species richness of parasitoids infesting Yponomeuta species in the Netherlands

    NARCIS (Netherlands)

    Cleary, Daniel F.R.

    2004-01-01

    Parasitoid assemblages infesting Yponomeuta species in the Netherlands were investigated. Parasitoid species richness and community composition were related to host species, habitat, temporal and spatial variation. Both community structure and species richness did not differ among habitats. There

  10. Species and speciation in the fossil record

    National Research Council Canada - National Science Library

    Allmon, Warren D; Yacobucci, Margaret M

    2016-01-01

    "Although the species is one of the fundamental units of biological classification, there is remarkably little consensus among biologists about what defines a species, even within distinct subdisciplines...

  11. Seven new Malesian species of Ficus (Moraceae)

    NARCIS (Netherlands)

    Berg, C.C.

    2012-01-01

    Descriptions of seven new species, Ficus buntaensis, F. flavistipulata, F. jambiensis, F. porata, F. samarana, F. sorongensis and F. temburongensis are presented and the related species briefly discussed.

  12. Molecular Epidemiology of Fonsecaea Species

    NARCIS (Netherlands)

    Najafzadeh, M.J.; Sun, J.; Vicente, V.A.; Klaassen, C.H.W.; Bonifaz, A.; Gerrits van den Ende, A.H.G.; Menken, S.B.J.; de Hoog, G.S.

    2011-01-01

    To assess population diversities among 81 strains of fungi in the genus Fonsecaea that had been identified down to species level, we applied amplified fragment-length polymorphism (AFLP) technology and sequenced the internal transcribed spacer regions and the partial cell division cycle, β-tubulin,

  13. Chromosome synteny in cucumis species

    Science.gov (United States)

    Cucumber, Cucumis sativus L. (2n = 2x = 14) and melon, C. melo L. (2n = 2x = 24) are two important vegetable species in the genus Cucumis (family Cucurbitaceae). Two inter-fertile botanical varieties with 14 chromosomes, the cultivated C. sativus var. sativus L. and the wild C. sativus var. hardwick...

  14. Phylogenetic relationships among Maloideae species

    Science.gov (United States)

    The Maloideae is a highly diverse sub-family of the Rosaceae containing several agronomically important species (Malus sp. and Pyrus sp.) and their wild relatives. Previous phylogenetic work within the group has revealed extensive intergeneric hybridization and polyploidization. In order to develop...

  15. Thromboelastography in Selected Avian Species

    DEFF Research Database (Denmark)

    Andersen, Sophie Susanna Strindberg; Nielsen, Tenna W; Ribeiro, Ângela M

    2015-01-01

    . Regardless of the mode of activation, clot formation in the species studied was markedly delayed compared with mammals. Because of prolonged reaction time (14.7-52.7 minutes) with kaolin and diluted tissue factor, undiluted human tissue factor was used in all avian samples because it provided the shortest...

  16. Nickel Homeostasis in Helicobacter Species

    NARCIS (Netherlands)

    J. Stoof (Jeroen)

    2011-01-01

    textabstractGastric Helicobacter species are adapted to colonize the acidic environment of the stomach. Colonization with H pylori is life long if untreated, and can lead to gastritis, peptic ulcer disease and eventually to gastric cancer. Although H pylori is sensitive to many antibiotics in vitro,

  17. Botrytis species on bulb crops

    NARCIS (Netherlands)

    Lorbeer, J.W.; Seyb, A.M.; Boer, de M.; Ende, van den J.E.

    2007-01-01

    Abstract. A number of Botrytis species are pathogens of bulb crops. Botrytis squamosa (teleomorph= Botrytotinia squamosa) causal agent of botrytis leaf blight and B. allii the causal agent of botrytis neck rot are two of the most important fungal diseases of onion. The taxonomics of several of the n

  18. Man...An Endangered Species?

    Science.gov (United States)

    Department of the Interior, Washington, DC.

    The general theme of this 1968 yearbook is that man is a threatened species, facing overpopulation and unbridled technology - both self induced. The presentation is broad, relating to many aspects of conservation and natural resources in the United States in a descriptive, non-technical style. The yearbook is divided into major topics: Land…

  19. Man...An Endangered Species?

    Science.gov (United States)

    Department of the Interior, Washington, DC.

    The general theme of this 1968 yearbook is that man is a threatened species, facing overpopulation and unbridled technology - both self induced. The presentation is broad, relating to many aspects of conservation and natural resources in the United States in a descriptive, non-technical style. The yearbook is divided into major topics: Land…

  20. Fifteen new species of Penicillium

    NARCIS (Netherlands)

    Visagie, C.M.; Renaud, J.B.; Burgess, K.M.N.; Malloch, D.W.; Clark, D.; Ketch, L.; Urb, M.; Louis-Seize, G.; Assabgui, R.; Sumarah, M.W.; Seifert, K.A.

    2016-01-01

    We introduce 15 new species of Penicillium isolated from a diverse range of locations, including Canada, Costa Rica, Germany, Italy, New Zealand, Tanzania, USA and the Dry Valleys of Antarctica, from a variety of habitats, including leaf surfaces in tropical rain forests, soil eaten by chimpanzees,

  1. 76 FR 74778 - Endangered Species

    Science.gov (United States)

    2011-12-01

    ... National Oceanic and Atmospheric Administration RIN 0648-XA850 Endangered Species AGENCY: National Marine..., notice was published in the Federal Register (76 FR 33703) that a request for a scientific research... with passive integrated transponder (PIT) tags and Floy tags, if untagged; and sample genetic fin...

  2. The complete mitochondrial genome of Metorchis orientalis (Trematoda: Opisthorchiidae): Comparison with other closely related species and phylogenetic implications.

    Science.gov (United States)

    Na, Lu; Gao, Jun-Feng; Liu, Guo-Hua; Fu, Xue; Su, Xin; Yue, Dong-Mei; Gao, Yuan; Zhang, Yan; Wang, Chun-Ren

    2016-04-01

    Metorchis orientalis (Trematoda: Opisthorchiidae) is an important trematode infecting many animals and humans, causing metorchiasis. In the present study, the complete mitochondrial (mt) genome of M. orientalis was sequenced. The complete mt genome of M. orientalis is 13,834 bp circular DNA molecule and contains 12 protein-coding genes, 22 transfer RNA genes, and two ribosomal RNA genes. The gene content and arrangement of M. orientalis is the same as those of Opisthorchiidae trematodes (Opisthorchis viverrini, Opisthorchis felineus and Clonorchis sinensis), but distinct from Schistosoma spp. Phylogenetic analyses using concatenated amino acid sequences of 12 protein-coding genes with three different computational algorithms (Bayesian inference, maximum likelihood and maximum parsimony) revealed that M. orientalis and O. viverrini represent sister taxa. The mt genome provides a novel genetic marker for further studies of the identification, classification and molecular epidemiology of Opisthorchiidae trematodes, and should have implications for the diagnosis, prevention and control of metorchiasis in animals and humans. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Optimal conservation of migratory species.

    Directory of Open Access Journals (Sweden)

    Tara G Martin

    Full Text Available BACKGROUND: Migratory animals comprise a significant portion of biodiversity worldwide with annual investment for their conservation exceeding several billion dollars. Designing effective conservation plans presents enormous challenges. Migratory species are influenced by multiple events across land and sea-regions that are often separated by thousands of kilometres and span international borders. To date, conservation strategies for migratory species fail to take into account how migratory animals are spatially connected between different periods of the annual cycle (i.e. migratory connectivity bringing into question the utility and efficiency of current conservation efforts. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report the first framework for determining an optimal conservation strategy for a migratory species. Employing a decision theoretic approach using dynamic optimization, we address the problem of how to allocate resources for habitat conservation for a Neotropical-Nearctic migratory bird, the American redstart Setophaga ruticilla, whose winter habitat is under threat. Our first conservation strategy used the acquisition of winter habitat based on land cost, relative bird density, and the rate of habitat loss to maximize the abundance of birds on the wintering grounds. Our second strategy maximized bird abundance across the entire range of the species by adding the constraint of maintaining a minimum percentage of birds within each breeding region in North America using information on migratory connectivity as estimated from stable-hydrogen isotopes in feathers. We show that failure to take into account migratory connectivity may doom some regional populations to extinction, whereas including information on migratory connectivity results in the protection of the species across its entire range. CONCLUSIONS/SIGNIFICANCE: We demonstrate that conservation strategies for migratory animals depend critically upon two factors: knowledge of

  4. Species recovery in the United States: Increasing the effectiveness of the Endangered Species Act

    Science.gov (United States)

    Daniel M. Evans; Judy P. Che-Castaldo; Deborah Crouse; Frank W. Davis; Rebecca Epanchin-Niell; Curtis H. Flather; R. Kipp Frohlich; Dale D. Goble; Ya-Wei Li; Timothy D. Male; Lawrence L. Master; Matthew P. Moskwik; Maile C. Neel; Barry R. Noon; Camille Parmesan; Mark W. Schwartz; J. Michael Scott; Byron K. Williams

    2016-01-01

    The Endangered Species Act (ESA) has succeeded in shielding hundreds of species from extinction and improving species recovery over time. However, recovery for most species officially protected by the ESA - i.e., listed species - has been harder to achieve than initially envisioned. Threats to species are persistent and pervasive, funding has been insufficient...

  5. Modelling biological invasions: species traits, species interactions, and habitat heterogeneity.

    Science.gov (United States)

    Cannas, Sergio A; Marco, Diana E; Páez, Sergio A

    2003-05-01

    In this paper we explore the integration of different factors to understand, predict and control ecological invasions, through a general cellular automaton model especially developed. The model includes life history traits of several species in a modular structure interacting multiple cellular automata. We performed simulations using field values corresponding to the exotic Gleditsia triacanthos and native co-dominant trees in a montane area. Presence of G. triacanthos juvenile bank was a determinant condition for invasion success. Main parameters influencing invasion velocity were mean seed dispersal distance and minimum reproductive age. Seed production had a small influence on the invasion velocity. Velocities predicted by the model agreed well with estimations from field data. Values of population density predicted matched field values closely. The modular structure of the model, the explicit interaction between the invader and the native species, and the simplicity of parameters and transition rules are novel features of the model.

  6. Supplementary studies of Pleurogenoides medians (Digenea: Lecithodendriidae infecting the Marsh frog Rana Ridibunda (Amphibia: Ranidae in Egypt

    Directory of Open Access Journals (Sweden)

    Rewaida Abdel-Gaber

    2017-06-01

    Full Text Available Pleurogenoides medians, a digenean lecithodendriid trematode, parasitize numerous aquatic vertebrate species including frogs, freshwater fish, urodeles and anurans. In the present study, a total of 190 out of 300 (63.33% marsh frogs Rana Ridibunda were found to be infected with this digenean parasite. The highest percentage of infection was recorded in winter reaching 93.33%, and the lowest value was recorded to be 6.66% during summer. Prevalence and intensity of infection were positively correlated with the host size. Host sex showed no effect in this respect. Morphological studies based on light and scanning electron microscopy revealed that the adult worms characterized by small body size measured 1.980–2.430 (2.205 ± 0.1 mm long and 0.870–1.20 (9.87 ± 0.01 mm wide with spines of similar size distributed all over the body surface; oral sucker is sub-terminal and measured 0.180–0.230 (0.203 ± 0.01 mm long and 0.120–0.180 (0.150 ± 0.01 mm wide; ventral sucker is smaller than the oral sucker, post-ovarian located at 1/3 level from the anterior end and measured 0.080–0.102 (0.090 ± 0.001 mm long and 0.100–0140 (0.120 ± 0.001 mm wide; two symmetrical testes were located near the cecal termination on both sides of the ventral sucker, measured 0.153–0.193 (0.176 ± 0.01 mm long and 0.160–0.192 (0.175 ± 0.01 mm wide; pre-acetabular ovary was present and measured 0.130–0.150 (0.140 ± 0.01 mm long and 0.100–0.130 (0.120 ± 0.01 mm wide; vitellaria are extra-caecal and extended from the level of the pharynx to a level slightly beyond the ovary. By comparing the recovered parasite with different species of the same genus from different hosts having different localities, it was found that the present species morphometrically more or less different from the comparable species and the only similar species was P. medians described previously from the common toad Bufo bufo by having all similar

  7. Allelopathy of plant species of pharmaceutical importance to cultivated species

    Directory of Open Access Journals (Sweden)

    Álisson Sobrinho Maranho

    2012-11-01

    Full Text Available This study aimed to identify possible allelopathic effects of leaf aqueous extracts of Baccharis dracunculifolia DC., Pilocarpus pennatifolius Lem., Cyperus rotundus L., Morus rubra L., Casearia sylvestris Sw., and Plectranthus barbatus Andr. on the germination and initial growth of Lactuca sativa L., Brassica oleracea L. cv. capitata, B. oleracea L. cv. italica, B. pekinenses L., B. campestris L., Lycopersicum esculentum Miller, and Eruca sativa L. To obtain the aqueous extracts, leaves previously dried at a 1g.10mL-1 concentration were used, diluted in six solutions (10, 30, 50, 70, 90, and 100% and compared to control, distilled water, with five replications of 10 seeds for all vegetable species. The aqueous extracts of all species showed allelopathic potential for germination of seeds, the germination speed index, and the initial growth of shoots and roots of vegetable crops. The aqueous extracts of C. rotundus and P. barbatus promoted lower and higher allelopathic effects, respectively, and the vegetal structure mostly affected by the extracts was the primary root. The results indicate the existence of allelopathic potential in the species tested, so there’s a need for adopting care procedures when cultivating vegetables with them.

  8. ICRAF Species Switchboard. Version 1.2

    DEFF Research Database (Denmark)

    Kindt, R.; Ordonez, J.; Smith, E.;

    2015-01-01

    The current version of the Agroforestry Species Switchboard documents the presence of a total of 26,135 plant species (33,813 species including synonyms) across 19 web-based databases. When available, hyperlinks to information on the selected species in particular databases are provided. In total...

  9. The myth of plant species saturation

    Science.gov (United States)

    Thomas J. Stohlgren; David T. Barnett; Catherine S. Jarnevich; Curtis Flather; John Kartesz

    2008-01-01

    Plant species assemblages, communities or regional floras might be termed saturated when additional immigrant species are unsuccessful at establishing due to competitive exclusion or other inter-specific interactions, or when the immigration of species is off-set by extirpation of species. This is clearly not the case for state, regional or national floras in the USA...

  10. ICRAF Species Switchboard. Version 1.2

    DEFF Research Database (Denmark)

    Kindt, R.; Ordonez, J.; Smith, E.

    2015-01-01

    The current version of the Agroforestry Species Switchboard documents the presence of a total of 26,135 plant species (33,813 species including synonyms) across 19 web-based databases. When available, hyperlinks to information on the selected species in particular databases are provided. In total...

  11. A new species of Sporothrix from Kuwait

    NARCIS (Netherlands)

    Moustafa, A.F.

    1981-01-01

    During an ecological study of fungi of the tidal mudflats in Kuwait, a Sporothrix species has been recorded twice, in 1977 and 1980. It differs from other species of the genus (de Hoog, 1974, 1978) in several characters and is here described as a new species. A comparison with similar species of the

  12. Comparative genomics of Listeria species.

    Science.gov (United States)

    Glaser, P; Frangeul, L; Buchrieser, C; Rusniok, C; Amend, A; Baquero, F; Berche, P; Bloecker, H; Brandt, P; Chakraborty, T; Charbit, A; Chetouani, F; Couvé, E; de Daruvar, A; Dehoux, P; Domann, E; Domínguez-Bernal, G; Duchaud, E; Durant, L; Dussurget, O; Entian, K D; Fsihi, H; García-del Portillo, F; Garrido, P; Gautier, L; Goebel, W; Gómez-López, N; Hain, T; Hauf, J; Jackson, D; Jones, L M; Kaerst, U; Kreft, J; Kuhn, M; Kunst, F; Kurapkat, G; Madueno, E; Maitournam, A; Vicente, J M; Ng, E; Nedjari, H; Nordsiek, G; Novella, S; de Pablos, B; Pérez-Diaz, J C; Purcell, R; Remmel, B; Rose, M; Schlueter, T; Simoes, N; Tierrez, A; Vázquez-Boland, J A; Voss, H; Wehland, J; Cossart, P

    2001-10-26

    Listeria monocytogenes is a food-borne pathogen with a high mortality rate that has also emerged as a paradigm for intracellular parasitism. We present and compare the genome sequences of L. monocytogenes (2,944,528 base pairs) and a nonpathogenic species, L. innocua (3,011,209 base pairs). We found a large number of predicted genes encoding surface and secreted proteins, transporters, and transcriptional regulators, consistent with the ability of both species to adapt to diverse environments. The presence of 270 L. monocytogenes and 149 L. innocua strain-specific genes (clustered in 100 and 63 islets, respectively) suggests that virulence in Listeria results from multiple gene acquisition and deletion events.

  13. Fifteen new species of Penicillium.

    Science.gov (United States)

    Visagie, C M; Renaud, J B; Burgess, K M N; Malloch, D W; Clark, D; Ketch, L; Urb, M; Louis-Seize, G; Assabgui, R; Sumarah, M W; Seifert, K A

    2016-06-01

    We introduce 15 new species of Penicillium isolated from a diverse range of locations, including Canada, Costa Rica, Germany, Italy, New Zealand, Tanzania, USA and the Dry Valleys of Antarctica, from a variety of habitats, including leaf surfaces in tropical rain forests, soil eaten by chimpanzees, infrabuccal pockets of carpenter ants, intestinal contents of caterpillars and soil. The new species are classified in sections Aspergilloides (1), Canescentia (2), Charlesia (1), Exilicaulis (3), Lanata-Divaricata (7) and Stolkia (1). Each is characterised and described using classical morphology, LC-MS based extrolite analyses and multigene phylogenies based on ITS, BenA and CaM. Significant extrolites detected include andrastin, pulvilloric acid, penitrem A and citrinin amongst many others.

  14. Charcoal anatomy of forest species

    Directory of Open Access Journals (Sweden)

    Graciela Inés Bolzon de Muñiz1

    2012-09-01

    Full Text Available Vegetal charcoal retains the anatomical structure of the wood and may permit its botanical identification, which depends on species characteristics, the charcoal fragments size and preservation state. Anatomical characterization of ten forest species charcoal was done envisaging the identification and control of illegal charcoal. Differences between gymnosperms and angiosperms are evident in carbonized wood. Vessel diameter was statistically different between wood and charcoal in Vatairea guianensis, Mezilaurus itauba, Calophyllum brasiliense e Qualea cf. acuminata, and vessel frequency in Vatairea guianensis, Manilkara huberi, Qualea cf. acuminata e Simarouba amara. The anatomical structure from wood, in general aspects, is constant during carbonization process using temperature of 450°C, being possible to identify the material by using its cellular components.

  15. Two living species of coelacanths?

    OpenAIRE

    Holder, Mark T.; Erdmann, Mark V.; Wilcox, Thomas P; Caldwell, Roy L.; David M Hillis

    1999-01-01

    During the period of September 1997 through July 1998, two coelacanth fishes were captured off Manado Tua Island, Sulawesi, Indonesia. These specimens were caught almost 10,000 km from the only other known population of living coelacanths, Latimeria chalumnae, near the Comores. The Indonesian fish was described recently as a new species, Latimeria menadoensis, based on morphological differentiation and DNA sequence divergence in fragments of the cytochrome b and 12S rRNA genes. We have obtain...

  16. Native Terrestrial Animal Species Richness

    Science.gov (United States)

    These data represent predicted current distributions of all native mammals, birds, reptiles, amphibians and butterflies in the Middle-Atlantic region. The data are available for both 8-digit HUCs and EMAP hexagons and represent total species counts for each spatial unit. More information about these resources, including the variables used in this study, may be found here: https://edg.epa.gov/data/Public/ORD/NERL/ReVA/ReVA_Data.zip.

  17. Recognizing species, present and past.

    Science.gov (United States)

    Tattersall, Ian

    2014-01-01

    Nobody disputes that nature is meaningfully "packaged" in some way. But debate persists over exactly how (and even whether) the boundaries dividing taxa should (can) be drawn. At one end of the scale, some zealots abstrusely deny real existence to higher taxa.(1) At the other, laborers at the taxonomic rock-face confront genuine challenges in recognizing and delineating the species that systematists agree constitute the most fundamental unit of taxonomic analysis.

  18. Arsenic Species in Marine Samples

    OpenAIRE

    Francesconi, Kevin A.; Edmonds, John S.

    1998-01-01

    Arsenic occurs in seawater, in predominantly inorganic forms, at concentrations of about 1-2 μg/L. These concentrations are higher than those of most other potentially toxic metals and semimetals. Marine organisms have coped by exploiting the rich organic chemistry of arsenic to transform inorganic arsenic into a range of essentially non-toxic organoarsenic compounds. The resulting diversity of arsenic species found in marine samples is reviewed together with an overview of analytical meth...

  19. Cyanogenesis in Lotus and Trifolium species

    OpenAIRE

    Halina Blaim; Edmunt Nowacki

    2015-01-01

    The occurrence of cyanogenic plants was determined in 48 Trifolium species, 12 Lotus species, in wild population as well as in varieties of T. repens L. and Loins corniculatus L. species. In the genus Trifolium only T. nigrescens Viv. proved to be high-cyanogenic, all the remaining species are acyanogenic or low-cyanogenic. In the T. repens species varieties and wild populations include an insignificant per cent of cyanogenic plants.The genus Lotus comprises both high-cyanogenic and acyanogen...

  20. Bovine and ovine rumen fluke in Ireland-Prevalence, risk factors and species identity based on passive veterinary surveillance and abattoir findings.

    Science.gov (United States)

    Toolan, Dónal P; Mitchell, Gillian; Searle, Kate; Sheehan, Maresa; Skuce, Philip J; Zadoks, Ruth N

    2015-09-15

    The prevalence of rumen fluke, the incidence of clinical paramphistomosis and the trematode's species identity were studied in cattle and sheep in the Republic of Ireland using passive veterinary surveillance (faecal examination and necropsy results; 2010-2013) and abattoir data. Based on faecal examination, the prevalence of rumen fluke was higher in cattle than in sheep. Rumen fluke prevalence in cattle and sheep fluctuated over the year and in most years (2011-2013), prevalence was higher in winter (December-February) than in summer (June-August). For 3 of 4 years studied, there was no correlation between monthly prevalence of rumen fluke and prevalence of liver fluke as estimated by faecal examination. At sample level, joint occurrence of rumen fluke and liver fluke was 1.1-2.0 times more common than would be expected under the assumption of independence. Based on necropsy data, a spike in deaths attributed to paramphistomosis was observed in 2012, when rainfall was unusually high. This spike in mortality was not accompanied by a spike in faecal prevalence, emphasizing that the incidence of disease, which is due to high burdens of juvenile rumen fluke in the gut, is not correlated with prevalence of infection, which is measured by faecal examination and reflects presence of adult fluke in the rumen. At slaughter, 52% of 518 cattle from 101 herds were positive for rumen fluke, compared to 14% of 158 sheep. Prevalence in cattle was higher than reported in most studies from mainland Europe and varied by animal category, age, sex, abattoir visit and location (county) of farm from which the animal was submitted for slaughter, but in multivariate analysis, only sampling month and county were significantly associated with detection of rumen fluke. The identity of rumen fluke in cattle and sheep was confirmed as Calicophoron daubneyi. Although C. daubneyi is thought to share an intermediate host snail with Fasciola hepatica, the differences in prevalence between host

  1. Sequencing and characterization of the complete mitochondrial genome from the pancreatic fluke Eurytrema pancreaticum (Trematoda: Dicrocoeliidae).

    Science.gov (United States)

    Chang, Qiao-Cheng; Liu, Guo-Hua; Gao, Jun-Feng; Zheng, Xu; Zhang, Yan; Duan, Hong; Yue, Dong-Mei; Fu, Xue; Su, Xin; Gao, Yuan; Wang, Chun-Ren

    2016-01-15

    The trematode Eurytrema pancreaticum is a parasite of ruminant pancreatic and bile ducts, and also occasionally infects humans, causing eurytremiasis. In spite of it being a common fluke of cattle and sheep in endemic regions, little is known about the genomic resources of the parasite. We sequenced the complete mitochondrial (mt) genome of E. pancreaticum. It is 15,031 bp in size, and encodes 36 genes: 12 protein-coding genes, two ribosomal RNA genes, and 22 transfer RNA genes. The E. pancreaticum mt gene order is the same as that of Dicrocoelium chinensis and Dicrocoelium dendriticum, and all genes are transcribed in the same direction. Phylogenetic analysis based on the concatenated amino acid sequences of 12 protein-coding genes by Bayesian inference shows that E. pancreaticum is closely related to D. chinensis and other members of the family Dicrocoeliidae with strong posterior probability support. The E. pancreaticum mt genome should prove to be a useful resource for comparative mt genomic studies of digenetic trematodes, and will provide a rich source of DNA markers for studies into the systematics, epidemiology, and population genetics of this parasite and other digenean trematodes. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. In vitro manipulation of gene expression in larval Schistosoma: a model for postgenomic approaches in Trematoda

    Science.gov (United States)

    YOSHINO, TIMOTHY P.; DINGUIRARD, NATHALIE; DE MORAES MOURÃO, MARINA

    2013-01-01

    SUMMARY With rapid developments in DNA and protein sequencing technologies, combined with powerful bioinformatics tools, a continued acceleration of gene identification in parasitic helminths is predicted, potentially leading to discovery of new drug and vaccine targets, enhanced diagnostics and insights into the complex biology underlying host-parasite interactions. For the schistosome blood flukes, with the recent completion of genome sequencing and comprehensive transcriptomic datasets, there has accumulated massive amounts of gene sequence data, for which, in the vast majority of cases, little is known about actual functions within the intact organism. In this review we attempt to bring together traditional in vitro cultivation approaches and recent emergent technologies of molecular genomics, transcriptomics and genetic manipulation to illustrate the considerable progress made in our understanding of trematode gene expression and function during development of the intramolluscan larval stages. Using several prominent trematode families (Schistosomatidae, Fasciolidae, Echinostomatidae), we have focused on the current status of in vitro larval isolation/cultivation as a source of valuable raw material supporting gene discovery efforts in model digeneans that include whole genome sequencing, transcript and protein expression profiling during larval development, and progress made in the in vitro manipulation of genes and their expression in larval trematodes using transgenic and RNA interference (RNAi) approaches. PMID:19961646

  3. Floral reward in Ranunculaceae species

    Directory of Open Access Journals (Sweden)

    Bożena Denisow

    2016-04-01

    Full Text Available Floral reward is important in ecological and evolutionary perspectives and essential in pollination biology. For example, floral traits, nectar and pollen features are essential for understanding the functional ecology, the dynamics of pollen transport, competition for pollinator services, and patterns of specialization and generalization in plant–pollinator interactions. We believe to present a synthetic description in the field of floral reward in Ranunculaceae family important in pollination biology and indicating connections between ecological and evolutionary approaches. The links between insect visitors’ behaviour and floral reward type and characteristics exist. Ranunculaceae is a family of aboot 1700 species (aboot 60 genera, distributed worldwide, however the most abundant representatives are in temperate and cool regions of the northern and southern hemispheres. The flowers are usually radially symmetric (zygomorphic and bisexual, but in Aconitum, Aquilegia are bilaterally symmetric (zygomorphic. Most Ranunculaceae flowers offer no nectar, only pollen (e.g., Ranunculus, Adonis vernalis, Thalictrum, but numerous species create trophic niches for different wild pollinators (e.g. Osmia, Megachile, Bombus, Andrena (Denisow et al. 2008. Pollen is a source of protein, vitamins, mineral salts, organic acids and hormones, but the nutritional value varies greatly between different plant species. The pollen production can differ significantly between Ranunculacea species. The mass of pollen produced in anthers differ due to variations in the number of developed anthers. For example, interspecies differences are considerable, 49 anthers are noted in Aquilegia vulgaris, 70 anthers in Ranunculus lanuginosus, 120 in Adonis vernalis. A significant intra-species differences’ in the number of anthers are also noted (e.g. 41 to 61 in Aquilegia vulgaris, 23-45 in Ranunculus cassubicus. Pollen production can be up to 62 kg per ha for Ranunculus acer

  4. Alien species in the Finnish weed flora

    Directory of Open Access Journals (Sweden)

    T. HYVÖNEN

    2008-12-01

    Full Text Available The present study aimed at assessing the invasion of alien weed species in Finland based on a review of their occurrence in the Finnish weed flora. The evaluation was conducted for the three phases of the invasion process, i.e. introduction, naturalization and invasion. The literature review revealed that 815 alien weed species occur in Finland of which 314 are regarded as naturalized. Based on their occurrence in different climate zones, the risk of naturalization of new harmful alien weed species was deemed low for those species not currently found in Finland, but higher for species occurring as casual aliens in Finland. In the latter group, 10 species of concern were detected. Exploration of the distribution patterns of naturalized species within Finland revealed species occupancy to be dependent on the residence time of the species. Established neophytes can be expected to extend their ranges and to increase occupation of agricultural habitats in the future.;

  5. Natural Constraints to Species Diversification.

    Science.gov (United States)

    Lewitus, Eric; Morlon, Hélène

    2016-08-01

    Identifying modes of species diversification is fundamental to our understanding of how biodiversity changes over evolutionary time. Diversification modes are captured in species phylogenies, but characterizing the landscape of diversification has been limited by the analytical tools available for directly comparing phylogenetic trees of groups of organisms. Here, we use a novel, non-parametric approach and 214 family-level phylogenies of vertebrates representing over 500 million years of evolution to identify major diversification modes, to characterize phylogenetic space, and to evaluate the bounds and central tendencies of species diversification. We identify five principal patterns of diversification to which all vertebrate families hold. These patterns, mapped onto multidimensional space, constitute a phylogenetic space with distinct properties. Firstly, phylogenetic space occupies only a portion of all possible tree space, showing family-level phylogenies to be constrained to a limited range of diversification patterns. Secondly, the geometry of phylogenetic space is delimited by quantifiable trade-offs in tree size and the heterogeneity and stem-to-tip distribution of branching events. These trade-offs are indicative of the instability of certain diversification patterns and effectively bound speciation rates (for successful clades) within upper and lower limits. Finally, both the constrained range and geometry of phylogenetic space are established by the differential effects of macroevolutionary processes on patterns of diversification. Given these properties, we show that the average path through phylogenetic space over evolutionary time traverses several diversification stages, each of which is defined by a different principal pattern of diversification and directed by a different macroevolutionary process. The identification of universal patterns and natural constraints to diversification provides a foundation for understanding the deep-time evolution of

  6. The Invasive Species Forecasting System

    Science.gov (United States)

    Schnase, John; Most, Neal; Gill, Roger; Ma, Peter

    2011-01-01

    The Invasive Species Forecasting System (ISFS) provides computational support for the generic work processes found in many regional-scale ecosystem modeling applications. Decision support tools built using ISFS allow a user to load point occurrence field sample data for a plant species of interest and quickly generate habitat suitability maps for geographic regions of management concern, such as a national park, monument, forest, or refuge. This type of decision product helps resource managers plan invasive species protection, monitoring, and control strategies for the lands they manage. Until now, scientists and resource managers have lacked the data-assembly and computing capabilities to produce these maps quickly and cost efficiently. ISFS focuses on regional-scale habitat suitability modeling for invasive terrestrial plants. ISFS s component architecture emphasizes simplicity and adaptability. Its core services can be easily adapted to produce model-based decision support tools tailored to particular parks, monuments, forests, refuges, and related management units. ISFS can be used to build standalone run-time tools that require no connection to the Internet, as well as fully Internet-based decision support applications. ISFS provides the core data structures, operating system interfaces, network interfaces, and inter-component constraints comprising the canonical workflow for habitat suitability modeling. The predictors, analysis methods, and geographic extents involved in any particular model run are elements of the user space and arbitrarily configurable by the user. ISFS provides small, lightweight, readily hardened core components of general utility. These components can be adapted to unanticipated uses, are tailorable, and require at most a loosely coupled, nonproprietary connection to the Web. Users can invoke capabilities from a command line; programmers can integrate ISFS's core components into more complex systems and services. Taken together, these

  7. VIDAS Listeria species Xpress (LSX).

    Science.gov (United States)

    Johnson, Ronald; Mills, John

    2013-01-01

    The AOAC GovVal study compared the VIDAS Listeria species Xpress (LSX) to the Health Products and Food Branch MFHPB-30 reference method for detection of Listeria on stainless steel. The LSX method utilizes a novel and proprietary enrichment media, Listeria Xpress broth, enabling detection of Listeria species in environmental samples with the automated VIDAS in a minimum of 26 h. The LSX method also includes the use of the chromogenic media, chromID Ottaviani Agosti Agar (OAA) and chromID Lmono for confirmation of LSX presumptive results. In previous AOAC validation studies comparing VIDAS LSX to the U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA-BAM) and the U.S. Department of Agriculture-Food Safety and Inspection Service (USDA-FSIS) reference methods, the LSX method was approved as AOAC Official Method 2010.02 for the detection of Listeria species in dairy products, vegetables, seafood, raw meats and poultry, and processed meats and poultry, and as AOAC Performance Tested Method 100501 in a variety of foods and on environmental surfaces. The GovVal comparative study included 20 replicate test portions each at two contamination levels for stainless steel where fractionally positive results (5-15 positive results/20 replicate portions tested) were obtained by at least one method at one level. Five uncontaminated controls were included. In the stainless steel artificially contaminated surface study, there were 25 confirmed positives by the VIDAS LSX assay and 22 confirmed positives by the standard culture methods. Chi-square analysis indicated no statistical differences between the VIDAS LSX method and the MFHPB-30 standard methods at the 5% level of significance. Confirmation of presumptive LSX results with the chromogenic OAA and Lmono media was shown to be equivalent to the appropriate reference method agars. The data in this study demonstrate that the VIDAS LSX method is an acceptable alternative method to the MFHPB-30 standard

  8. Biodiversity conservation including uncharismatic species

    DEFF Research Database (Denmark)

    Muñoz, Joaquin

    2007-01-01

    Recent papers mention ideas on the topics of biodiversity conservation strategies and priorities (Redford et al. 2003; Lamoreux et al. 2006; Rodrı´guez et al. 2006), the current status of biodiversity (Loreau et al. 2006), the obligations of conservation biologists regarding management policies...... (Chapron 2006; Schwartz 2006), and the main threats to biodiversity (including invasive species) (Bawa 2006). I suggest, however, that these articles do not really deal with biodiversity. Rather, they all focus on a few obviously charismatic groups (mammals, birds, some plants, fishes, human culture...

  9. Two living species of coelacanths?

    Science.gov (United States)

    Holder, Mark T.; Erdmann, Mark V.; Wilcox, Thomas P.; Caldwell, Roy L.; Hillis, David M.

    1999-01-01

    During the period of September 1997 through July 1998, two coelacanth fishes were captured off Manado Tua Island, Sulawesi, Indonesia. These specimens were caught almost 10,000 km from the only other known population of living coelacanths, Latimeria chalumnae, near the Comores. The Indonesian fish was described recently as a new species, Latimeria menadoensis, based on morphological differentiation and DNA sequence divergence in fragments of the cytochrome b and 12S rRNA genes. We have obtained the sequence of 4,823 bp of mitochondrial DNA from the same specimen, including the entire genes for cytochrome b, 12S rRNA, 16S rRNA, four tRNAs, and the control region. The sequence is 4.1% different from the published sequence of an animal captured from the Comores, indicating substantial divergence between the Indonesian and Comorean populations. Nine morphological and meristic differences are purported to distinguish L. menadoensis and L. chalumnae, based on comparison of a single specimen of L. menadoensis to a description of five individuals of L. chalumnae from the Comores. A survey of the literature provided data on 4 of the characters used to distinguish L. menadoensis from L. chalumnae from an additional 16 African coelacanths; for all 4 characters, the Indonesian sample was within the range of variation reported for the African specimens. Nonetheless, L. chalumnae and L. menadoensis appear to be separate species based on divergence of mitochondrial DNA. PMID:10535971

  10. Automated bioacoustic identification of species

    Directory of Open Access Journals (Sweden)

    David Chesmore

    2004-06-01

    Full Text Available Research into the automated identification of animals by bioacoustics is becoming more widespread mainly due to difficulties in carrying out manual surveys. This paper describes automated recognition of insects (Orthoptera using time domain signal coding and artificial neural networks. Results of field recordings made in the UK in 2002 are presented which show that it is possible to accurately recognize 4 British Orthoptera species in natural conditions under high levels of interference. Work is under way to increase the number of species recognized.Pesquisas sobre a identificação automatizada de animais através da bioacústica estão se ampliando, principalmente em vista das dificuldades para realizar levantamentos diretos. Este artigo descreve o reconhecimento automático de insetos Orthoptera utilizando a codificação de sinal no domínio temporal e redes neurais artificiais. Resultados de registros sonoros feitos no campo no Reino Unido em 2002 são apresentados, mostrando ser possível reconhecer corretamente 4 espécies britânicas de Orthoptera em condições naturais com altos níveis de interferências. Estão em andamento trabalhos para aumentar o número de espécies identificadas.

  11. Why some plant species are rare.

    Science.gov (United States)

    Wieger Wamelink, G W; Wamelink, G W Weiger; Goedhart, Paul W; Frissel, Joep; Frissel, Josep Y

    2014-01-01

    Biodiversity, including plant species diversity, is threatened worldwide as a result of anthropogenic pressures such as an increase of pollutants and climate change. Rare species in particular are on the verge of becoming extinct. It is still unclear as to why some plant species are rare and others are not. Are they rare due to: intrinsic reasons, dispersal capacity, the effects of management or abiotic circumstances? Habitat preference of rare plant species may play an important role in determining why some species are rare. Based on an extensive data set of soil parameters we investigated if rarity is due to a narrow habitat preference for abiotic soil parameters. For 23 different abiotic soil parameters, of which the most influential were groundwater-table, soil-pH and nutrient-contents, we estimated species responses for common and rare species. Based on the responses per species we calculated the range of occurrence, the range between the 5 and 95 percentile of the response curve giving the habitat preference. Subsequently, we calculated the average response range for common and rare species. In addition, we designed a new graphic in order to provide a better means for presentation of the results. The habitat preferences of rare species for abiotic soil conditions are significantly narrower than for common species. Twenty of the twenty-three abiotic parameters showed on average significantly narrower habitat preferences for rare species than for common species; none of the abiotic parameters showed on average a narrower habitat preference for common species. The results have major implications for the conservation of rare plant species; accordingly management and nature development should be focussed on the maintenance and creation of a broad range of environmental conditions, so that the requirements of rare species are met. The conservation of (abiotic) gradients within ecosystems is particularly important for preserving rare species.

  12. Molecular Diagnosis of Pathogenic Sporothrix Species

    NARCIS (Netherlands)

    Rodrigues, Anderson Messias; de Hoog, G Sybren; de Camargo, Zoilo Pires

    2015-01-01

    BACKGROUND: Sporotrichosis is a chronic (sub)cutaneous infection caused by thermodimorphic fungi in the order, Ophiostomatales. These fungi are characterized by major differences in routes of transmission, host predilections, species virulence, and susceptibilities to antifungals. Sporothrix species

  13. Tetrameranthus (Annonaceae revisited including a new species

    Directory of Open Access Journals (Sweden)

    Lubbert Y.Th. Westra

    2012-04-01

    Full Text Available The taxonomic revision of the infrequently collected genus Tetrameranthus by Westra (1985 is updated. A new species is described from French Guiana and Amapá, Brazil, increasing the number of species in this genus to seven.

  14. Assessing Pesticides under the Endangered Species Act

    Science.gov (United States)

    EPA’s pesticide risk assessment and regulatory processes ensure that protections are in place for all populations of non-target species. We have developed risk assessment procedures to determine potential for harm to individuals of a listed species.

  15. SIS - Species and Stock Administrative Data Set

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Species and Stock Administrative data set within the Species Information System (SIS) defines entities within the database that serve as the basis for recording...

  16. Species concepts do matter in nematology.

    Science.gov (United States)

    Ferris, V R

    1999-06-01

    Nematology is a taxon-based science, and a correct understanding of species and their relationships is basic to all nematological research. Modern methods of systematic analysis have reshaped issues concerning species recognition.

  17. SPECIES DISTRBUTION WITHIN RIPARIAN LANDCAPE ALONG ...

    African Journals Online (AJOL)

    Osondu

    2011-12-30

    Dec 30, 2011 ... The study examines species density and diversity distribution in riparian landscape along 18km stretch of. Mayo Kam. ... Result of species distribution revealed mean densities and diversities in zones A ..... map-based models.

  18. Anaho Island: Mammalian species richness report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This study assessed the mammalian species richness on Anaho Island using live trapping between July 18th and July 23rd 2005. The last mammalian species richness...

  19. New insights into the species problem

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Historical opinions of the "species problem" are briefly reviewed, and four salient stages are recognized according to origin of species concepts. We propose that species is the unit preserving superior gene assembly and is maintained by specific mechanisms. Based on characteristics of plant evolution, we assume that understanding plant species may include three stages, i.e. morphological recognition stage, multidisciplinary verification stage, and illuminating mechanisms preserving superior gene assembly.

  20. New species of Cystolepiota from China

    Directory of Open Access Journals (Sweden)

    Meng-Lin Xu

    2016-10-01

    Full Text Available In this paper, a new species, Cystolepiota pseudofumosifolia, is introduced. C. pseudofumosifolia is characterized by granulose or powdery pileus with an anatomic structure that is loosely globose, as well as ellipsoid cells in chains in the pileus covering the cheilocystidia. This new species is compared to the related and similar Cystolepiota species in morphology and molecular phylogeny based on Internal transcribed spacer sequences. Both types of data support our specimens as a new species in the genus Cystolepiota.

  1. Linking Keystone Species and Functional Groups: A New Operational Definition of the Keystone Species Concept

    Directory of Open Access Journals (Sweden)

    Robert D. Davic

    2003-07-01

    Full Text Available The concept of the "keystone species" is redefined to allow for the a priori prediction of these species within ecosystems. A keystone species is held to be a strongly interacting species whose top-down effect on species diversity and competition is large relative to its biomass dominance within a functional group. This operational definition links the community importance of keystone species to a specific ecosystem process, e.g., the regulation of species diversity, within functional groups at lower trophic levels that are structured by competition for a limited resource. The a priori prediction of keystone species has applied value for the conservation of natural areas.

  2. The Gilbertiodendron ogoouense species complex (Leguminosae

    NARCIS (Netherlands)

    Burgt, van der X.M.; Mackinder, B.A.; Wieringa, J.J.; Estrella, de la Manuel

    2015-01-01

    The Gilbertiodendron ogoouense species complex consists of 14 tree species. Eight species are here newly described and one is here reinstated: G. bambolense Burgt; G. breteleri Burgt; G. ebo Burgt & Mackinder; G. ecoukense (Pellegr.) Burgt; G. maximum Burgt & Wieringa; G. minkebense Burgt

  3. The South African Species of Commiphora

    Directory of Open Access Journals (Sweden)

    J. J.A. van der Walt

    1973-09-01

    Full Text Available A revision of the South African species of Commiphora (Burseraceae is presented in which 2 keys are provided to the 18 species recognized. A comprehensive morphological study, including an anatomical study of the stems and leaves, was regarded as essential for an accurate delimitation of the different species. Maps, sketches and photographs serve for illustration.

  4. Options in dealing with marine alien species

    NARCIS (Netherlands)

    Pelt-Heerschap, van H.M.L.; Sneekes, A.C.; Foekema, E.M.

    2015-01-01

    Invasive species can have strong impact on the local ecosystem, not only substantial impact on the local ecosystem, but also on economy and human health. This review on marine alien species outlines aspects of prevention, eradication and control strategies. When managing invasive species, prevention

  5. Biology, speciation, and utilization of peanut species

    Science.gov (United States)

    The genus Arachis has a large number of highly diverse species. Large collections of cultivated peanut exist at multiple locations and several hundreds of wild species are maintained in germplasm banks. Many of the species have been characterized for agronomic traits, but much of the germplasm colle...

  6. Eremophilanes and Pyrrolizidine Alkaloids of Senecioneae Species

    OpenAIRE

    2014-01-01

    The chemical study of two species of the tribe Senecioneae afforded two eremophilanes and two pyrrolizidine alkaloids from Se - necio subauriculatus and four modified eremophilanes from Roldana oaxacana . The chemistry of these species is in accord with that re - ported for species of Senecio and Roldana studied so far, and therefore, with the already described for the tribe Senecioneae.

  7. Brachyspira Species and Gastroenteritis in Humans

    NARCIS (Netherlands)

    Westerman, L.J.; Boer, de R.F.; Roelfsema, J.H.; Friesema, I.H.M.; Kortbeek, L.M.; Wagenaar, J.A.; Bonten, M.J.M.; Kusters, J.G.

    2013-01-01

    Brachyspira species have been implicated as a potential cause of gastroenteritis in humans; this is, however, controversial. In 733 gastroenteritis cases and 464 controls, we found 29 samples positive for Brachyspira species (2.3% of cases and 2.6% of controls; P = 0.77). Brachyspira species were no

  8. Brachyspira Species and Gastroenteritis in Humans

    NARCIS (Netherlands)

    Westerman, L.J.; Boer, de R.F.; Roelfsema, J.H.; Friesema, I.H.M.; Kortbeek, L.M.; Wagenaar, J.A.; Bonten, M.J.M.; Kusters, J.G.

    2013-01-01

    Brachyspira species have been implicated as a potential cause of gastroenteritis in humans; this is, however, controversial. In 733 gastroenteritis cases and 464 controls, we found 29 samples positive for Brachyspira species (2.3% of cases and 2.6% of controls; P = 0.77). Brachyspira species were

  9. The Gilbertiodendron ogoouense species complex (Leguminosae

    NARCIS (Netherlands)

    Burgt, van der X.M.; Mackinder, B.A.; Wieringa, J.J.; Estrella, de la Manuel

    2015-01-01

    The Gilbertiodendron ogoouense species complex consists of 14 tree species. Eight species are here newly described and one is here reinstated: G. bambolense Burgt; G. breteleri Burgt; G. ebo Burgt & Mackinder; G. ecoukense (Pellegr.) Burgt; G. maximum Burgt & Wieringa; G. minkebense Burgt

  10. Endangered Species & Biodiversity: A Classroom Project & Theme

    Science.gov (United States)

    Lauro, Brook

    2012-01-01

    Students discover the factors contributing to species losses worldwide by conducting a project about endangered species as a component of a larger classroom theme of biodiversity. Groups conduct research using online endangered- species databases and present results to the class using PowerPoint. Students will improve computer research abilities…

  11. Endangered Species & Biodiversity: A Classroom Project & Theme

    Science.gov (United States)

    Lauro, Brook

    2012-01-01

    Students discover the factors contributing to species losses worldwide by conducting a project about endangered species as a component of a larger classroom theme of biodiversity. Groups conduct research using online endangered- species databases and present results to the class using PowerPoint. Students will improve computer research abilities…

  12. 75 FR 69698 - Invasive Species Advisory Committee

    Science.gov (United States)

    2010-11-15

    ... Doc No: 2010-28653] DEPARTMENT OF THE INTERIOR Office of the Secretary Invasive Species Advisory..., notice is hereby given of meetings of the Invasive Species Advisory Committee (ISAC). Comprised of 30 nonfederal invasive species experts and stakeholders from across the nation, the purpose of the Advisory...

  13. 77 FR 23740 - Invasive Species Advisory Committee

    Science.gov (United States)

    2012-04-20

    ... Office of the Secretary Invasive Species Advisory Committee AGENCY: Office of the Secretary, Interior. ACTION: Notice of Public Meetings of the Invasive Species Advisory Committee. SUMMARY: Pursuant to the provisions of the Federal Advisory Committee Act, notice is hereby given of meetings of the Invasive Species...

  14. 76 FR 68776 - Invasive Species Advisory Committee

    Science.gov (United States)

    2011-11-07

    ...] [FR Doc No: 2011-28743] DEPARTMENT OF THE INTERIOR Office of the Secretary Invasive Species Advisory..., notice is hereby given of meetings of the Invasive Species Advisory Committee (ISAC). Comprised of 29 nonfederal invasive species experts and stakeholders from across the nation, the purpose of the Advisory...

  15. Invasive Species Science Update (No. 9)

    Science.gov (United States)

    Justin Runyon

    2017-01-01

    This newsletter is designed to keep managers and other users up-to-date with recently completed and ongoing research by RMRS scientists, as well as to highlight breaking news related to invasive species issues. The newsletter is produced by the RMRS Invasive Species Working Group (ISWG), a core group of scientists who volunteer to disseminate RMRS invasive species...

  16. 77 FR 40375 - Receipt of Applications for Endangered Species Permits

    Science.gov (United States)

    2012-07-09

    ... species, 14 fish species, 34 fresh-water mussel species, 2 snail species, 1 insect species, and 2 plant... Ecology Center, Gainesville, Florida Applicant requests authorization to conduct scientific research on...

  17. Ecological impacts of non-native species

    Science.gov (United States)

    Wilkinson, John W.

    2012-01-01

    Non-native species are considered one of the greatest threats to freshwater biodiversity worldwide (Drake et al. 1989; Allen and Flecker 1993; Dudgeon et al. 2005). Some of the first hypotheses proposed to explain global patterns of amphibian declines included the effects of non-native species (Barinaga 1990; Blaustein and Wake 1990; Wake and Morowitz 1991). Evidence for the impact of non-native species on amphibians stems (1) from correlative research that relates the distribution or abundance of a species to that of a putative non-native species, and (2) from experimental tests of the effects of a non-native species on survival, growth, development or behaviour of a target species (Kats and Ferrer 2003). Over the past two decades, research on the effects of non-native species on amphibians has mostly focused on introduced aquatic predators, particularly fish. Recent research has shifted to more complex ecological relationships such as influences of sub-lethal stressors (e.g. contaminants) on the effects of non-native species (Linder et al. 2003; Sih et al. 2004), non-native species as vectors of disease (Daszak et al. 2004; Garner et al. 2006), hybridization between non-natives and native congeners (Riley et al. 2003; Storfer et al. 2004), and the alteration of food-webs by non-native species (Nystrom et al. 2001). Other research has examined the interaction of non-native species in terms of facilitation (i.e. one non-native enabling another to become established or spread) or the synergistic effects of multiple non-native species on native amphibians, the so-called invasional meltdown hypothesis (Simerloff and Von Holle 1999). Although there is evidence that some non-native species may interact (Ricciardi 2001), there has yet to be convincing evidence that such interactions have led to an accelerated increase in the number of non-native species and cumulative impacts are still uncertain (Simberloff 2006). Applied research on the control, eradication, and

  18. Novel gaseous transient species: generation and characterization

    Institute of Scientific and Technical Information of China (English)

    ZENG XiaoQing; WANG DianXun

    2007-01-01

    Due to special properties of transient species, such as short-lived, unstable, reactive, and even explosive, the generation and subsequent characterization is a great challenge for experimental chemists. In our laboratory, systematic researches have been carried out to investigate novel transient species:reactive halogen species (RHS), short-lived free radicals, and metastable pseudohalogen compounds,based on the successive technical improvements on the Hel Photoelectron spectroscopy (PES). In this review, the topic mainly focuses on innovative methods of generating novel transient species, and subsequent geometric and electronic structure characterizations of these species combined with quantum chemical calculations.

  19. Alien species on the coasts of Turkey

    Directory of Open Access Journals (Sweden)

    M.E. CINAR

    2005-12-01

    Full Text Available The compilation of data on alien species reported from the Turkish coasts yielded a total of 263 species belonging to 11 systematic groups, of which Mollusca had the highest number of species (85 species, followed by Crustacea (51, fishes (43 and phytobenthos (39. The Black Sea is represented by a total of 20 alien species, the Sea of Marmara by 48 species, the Aegean Sea by 98 species and the Levantine Sea by 202 species. The majority of aliens found in the Black Sea and the Sea of Marmara were transported via shipping, whereas the Levantine coast is extensively subjected to Lessepsian migration. Benthic habitats (soft and hard substrata comprise 76% of the total alien species and the pelagic environment is inhabited by thirty-nine species. Almost 50% of aliens collected from the Turkish coasts were found only at 0-10 m depth. Eight species occur at depths deeper than 100 m. The impacts of aliens on the benthic and pelagic ecosystems are presented.

  20. Alien species on the coasts of Turkey

    Directory of Open Access Journals (Sweden)

    M.E. CINAR

    2012-12-01

    Full Text Available The compilation of data on alien species reported from the Turkish coasts yielded a total of 263 species belonging to 11 systematic groups, of which Mollusca had the highest number of species (85 species, followed by Crustacea (51, fishes (43 and phytobenthos (39. The Black Sea is represented by a total of 20 alien species, the Sea of Marmara by 48 species, the Aegean Sea by 98 species and the Levantine Sea by 202 species. The majority of aliens found in the Black Sea and the Sea of Marmara were transported via shipping, whereas the Levantine coast is extensively subjected to Lessepsian migration. Benthic habitats (soft and hard substrata comprise 76% of the total alien species and the pelagic environment is inhabited by thirty-nine species. Almost 50% of aliens collected from the Turkish coasts were found only at 0-10 m depth. Eight species occur at depths deeper than 100 m. The impacts of aliens on the benthic and pelagic ecosystems are presented.