1,721,061 research outputs found
Polystomoides bourgati (Monogenea: Polystomatidae) infecting Pelusios castaneus in southern Nigeria
No full textThe study of endoparasites (helminths and coccidians) in the Algerian (Atelerix algirus) and desert (Paraechinus aethiopicus) hedgehogs was performed between July 2008 and October 2009. The helminth species found included two cestodes, Mathevotaenia erinacei (Anoplocephalidae) and an unidentified cestode larva in the mesentery, eight species of nematode: Aonchotheca erinacei (Capillaridae) in the intestine, spirurids (Spiruridae) in the intestine, Crenosoma striatum (Crenosomatidae) in the lungs, Gongylonema mucronatum (Gongylonematidae) in the oesophagus, Physaloptera clausa (Physalopteridae) in the stomach, Physaloptera sp. larvae (Physalopteridae) in the mesentery, Pterygodermatites plagiostoma (Rictularidae) in the stomach, Spirura rytipleurites seurati (Spiruridae) in the intestine; and 2 acanthocephalans, Moniliformis moniliformis (Monoliformidae) in the intestine and larvae of an unknown acanthocephalan species in the mesentery. The general prevalence was high in both hosts, 92% in Atelerix algirus and 94.12% in Paraechinus aethiopicus. Physaloptera clausa was the most prevalent species (64.0% in Atelerix algirus and 64.7% in Paraechinus aethiopicus). Polyparasitism of helminths was 68% in Atelerix algirus and 52.9% in Paraechinus aethiopicus. Two coccidian species were detected in both hedgehogs, Isospora sp. and Eimeria sp. We provide the first complete parasitological data from Africa of these two hedgehogs
Resolving the confusion: Amietia vertebralis and A. umbraculata tadpole morphology
Get PDFMorphological similarities between the tadpoles of Amietia umbraculata and A. vertebralis have led to confusion and incorrect descriptions and identifications in the literature. Based on 33 body measurements and ratios we revised the morphological descriptions of the tadpoles of the two species. Tadpole identification was verified through DNA sequencing using mitochondrial (16S) gene fragments. A combination of four morphological characters proved to be informative and consistent in distinguishing between tadpoles of the two species. Tadpoles of A. umbraculata are characterised by having four labial tooth rows in the lower jaw, extensive tail mottling, a dorsal fin that originates well behind the body reaching a maximum depth at 50% of the tail length, and an average tail length of 1.9 times body length. Amietia vertebralis tadpoles on the other hand are characterised by having five or more labial tooth rows in the lower jaw, tail mottling that is confined to the upper half of the tail musculature, a dorsal fin that originates at the body-tail junction but retains a low profile, rising abruptly to reach a maximum depth at about 40% of the tail length, and an average tail length of 1.5 times body length. These four characters identify the two species without ambiguity
Correlating early evolution of parasitic platyhelminths to Gondwana breakup
Get PDFInvestigating patterns and processes of parasite diversification over ancient geological periods should involve comparisons of host and parasite phylogenies in a biogeographic context. It has been shown previously that the geographical distribution of host-specific parasites of sarcopterygians was guided, from Palaeozoic to Cainozoic times, mostly by evolution and diversification of their freshwater hosts. Here, we propose phylogenies of neobatrachian frogs and their specific parasites (Platyhelminthes, Monogenea) to investigate coevolutionary processes and historical biogeography of polystomes and further discuss all the possible assumptions that may account for the early evolution of these parasites. Phylogenetic analyses of concatenated rRNA nuclear genes (18S and partial 28S) supplemented by cophylogenetic and biogeographic vicariance analyses reveal four main parasite lineages that can be ascribed to centers of diversity, namely Australia, India, Africa, and South America. In addition, the relationships among these biogeographical monophyletic groups, substantiated by molecular dating, reflect sequential origins during the breakup of Gondwana. The Australian polystome lineage may have been isolated during the first stages of the breakup, whereas the Indian lineage would have arisen after the complete separation of western and eastern Gondwanan components. Next, polystomes would have codiverged with hyloid sensu stricto and ranoid frog lineages before the completion of South American and African plate separation. Ultimately, they would have undergone an extensive diversification in South America when their ancestral host families diversified. Therefore, the presence of polystome parasites in specific anuran host clades and in discrete geographic areas reveals the importance of biogeographic vicariance in diversification processes and supports the occurrence and radiation of amphibians over ancient and recent geological periods.http://dx.doi.org/10.1093/sysbio/syr078http://sysbio.oxfordjournals.org/content/60/6/762.full.pdf+htm
Polystoma okomuensis n. sp. (Monogenea: Polystomatidae) from Boulenger's striped frog, phlyctimantis boulengeri (Perret, 1986) in Nigeria
No full textPolystoma okomuensis is described as a new species of the Polystomatidae parasitic in the urinary bladder of Boulenger's striped frog Phlyctimantis boulengeri in the Okomu National Park, Edo State, Nigeria. Although other African polystomes have been reported from Nigeria, this is the first to be described from the country and the first from Phlyctimantis. It is distinguished from other African Polystoma species by a combination of characters, including the body size, size and shape of the hamuli, size and shape of marginal hooklets and intestinal location. Phlyctimantis boulengeri was found to be infected in two of four seasonal lakes where specimens were caught with prevalences and mean intensities ranging from 14.3 to 22% and 1.0 to 1.5, respectively. Of the total number of 45 frogs examined, the prevalence was 15.6% and mean intensity 1.4
Invasive species threat: parasite phylogenetics reveals patterns and processes of host-switching between non-native and native captive freshwater turtles
No full textSpecial Issue 13 (Systematics as a cornerstone of parasitology)One of the major threats to biodiversity involves biological invasions with direct consequences on the stability of ecosystems. In this context, the role of parasites is not negligible as it may enhance the success of invaders. The red-eared slider, Trachemys scripta elegans, has been globally considered among the worst invasive species. Since its introduction through the pet trade, T. s. elegans is now widespread and represents a threat for indigenous species. Because T. s. elegans coexists with Emys orbicularis and Mauremys leprosa in Europe, it has been suggested it may compete with the native turtle species and transmit pathogens. We examined parasite transfer from American captive to the two native species that co-exist in artificial pools of a Turtle Farm in France. As model parasite species we used platyhelminth worms of the family Polystomatidae (Monogenea) because polystomes have been described from American turtles in their native range. Phylogenetic relationships among polystomes parasitizing chelonian host species that are geographically widespread show patterns of diversification more complex than expected. Using DNA barcoding to identify species from adult and/or polystome eggs, several cases of host switching from exotic to indigenous individuals were illustrated, corroborating that parasite transmission is important when considering the pet trade and in reintroduction programmes to reinforce wild populations of indigenous species.http://dx.doi.org/10.1017/S003118201100033
First monogenean flatworm from a microhylid frog host: Kankana, a new polystome genus from Madagascar
No full textKankana manampoka n. gen., n. sp. (Monogenea, Polystomatidae), is described from the urinary bladder of the narrow-mouthed frog Platypelis pollicaris. This is the first record of a polystome from the Microhylidae and the third polystome genus from Madagascar, next to Metapolystoma and Madapolystoma. The extensive uterus and presence of hamuli resemble Metapolystoma but the vitellarium confined to the lateral fields in Kankana is different. Madapolystoma also has an extensive uterus but contain only up to 32 advanced developed larvae. Based on the extensive uterus filling the body proper and the vitellarium confined to two lateral fields posterior in the body this new polystome resembles Eupolystoma known from Africa and India. However, unlike Eupolystoma, the gonads are in the middle of the body, vaginae are lacking and a pair of hamuli is present. A molecular phylogenetic analysis of concatenated 18S and 28S ribosomal RNA gene sequences supplemented by genetic distances inferred from 28S and COI sequences showed that this new genus is more related to Madapolystoma, a genus only reported from Madagascar, than to Eupolystoma known from Africa and India and Metapolystoma known from Africa and Madagascar
Seasonal pattern of chytridiomycosis in common river frog (Amietia angolensis) tadpoles in the South African Grassland Biome
Get PDFEnvironmental parameters such as temperature and rainfall influence the biology of amphibians and are likely to similarly influence the growth and prevalence of associated pathogens. Amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), causes an infectious disease, chytridiomycosis, in amphibians worldwide. Field studies on post-metamorphic anurans from tropical Australia have correlated increased prevalence with cool winter temperatures, but similar studies are lacking from Africa. We monitored the seasonality of amphibian chytrid in the Highveld of South Africa through microscopic examination of common river frog (Amietia angolensis) tadpoles over 12 months.Within the study area Bd was found to be widespread, but largely limited to riverine systems. The seasonal infection pattern was inconsistent with the findings of past studies, which showed that prevalence usually peaks during the cooler months of the year. This study indicates that infection levels increased during spring in the Grassland Biome, when temperatures favoured optimum thermal growth of the fungus and when streams reached minimum flow levels
FIGURE 5 in A new genus of polystomatid parasitic flatworm (Monogenea: Polystomatidae) without free-swimming life stage from the Malagasy poison frogs
No full textFIGURE 5. Maximum Likelihood tree inferred from an analysis of 331 nucleotides of DNA sequences of the mitochondrial COI gene. Values along branches correspond to bootstrap proportions after 1,000 replicates. Letters [a] to [h] indicate different individuals of the same polystome candidate species.Published as part of Du, Louis H., Raharivololoniaina, Liliane, Verneau, Olivier & Vences, Miguel, 2010, A new genus of polystomatid parasitic flatworm (Monogenea: Polystomatidae) without free-swimming life stage from the Malagasy poison frogs, pp. 54-68 in Zootaxa 2722 on page 61, DOI: 10.5281/zenodo.19991
Multiple emergences of genetically diverse amphibian-infecting chytrids include a globalized hypervirulent recombinant lineage
Get PDFBatrachochytrium dendrobatidis (Bd) is a globally ubiquitous fungal infection that has emerged to become a primary driver of amphibian biodiversity loss. Despite widespread effort to understand the emergence of this panzootic, the origins of the infection, its patterns of global spread, and principle mode of evolution remain largely unknown. Using comparative population genomics, we discovered three deeply diverged lineages of Bd associated with amphibians. Two of these lineages were found in multiple continents and are associated with known introductions by the amphibian trade. We found that isolates belonging to one clade, the global panzootic lineage (BdGPL) have emerged across at least five continents during the 20th century and are associated with the onset of epizootics in North America, Central America, the Caribbean, Australia, and Europe. The two newly identified divergent lineages, Cape lineage (BdCAPE) and Swiss lineage (BdCH), were found to differ in morphological traits when compared against one another and BdGPL, and we show that BdGPL is hypervirulent. BdGPL uniquely bears the hallmarks of genomic recombination, manifested as extensive intergenomic phylogenetic conflict and patchily distributed heterozygosity. We postulate that contact between previously genetically isolated allopatric populations of Bd may have allowed recombination to occur, resulting in the generation, spread, and invasion of the hypervirulent BdGPL leading to contemporary disease-driven losses in amphibian biodiversity.http://dx.doi.org/10.1073/pnas.1111915108http://www.pnas.org/content/108/46/18732.full?sid=4f17ecfa-91ec-4d2f-add0-090003e332d
Like host, like parasite: intraspecific divergence in a polystomatid flatworm parasite across South Africa echoes that of its frog host
No full textABSTRACT The African Clawed Frog Xenopus laevis , a global invader, exhibits marked phylogeographic divergence among native populations in southern Africa, which enhances its invasive potential. The polystomatid flatworm Protopolystoma xenopodis , as the frog’s most frequently co-introduced metazoan parasite, may be the ideal biological tag for the frog’s movement, if corresponding divergence can be demonstrated. In an integrative approach, we utilised morphometrics and molecular markers to assess divergence in P. xenopodis in its native range. We measured twelve key morphological characters from 23 flatworms and compared these statistically between flatworms collected to the north and south of the Great Escarpment Mountain Range in South Africa. Phylogenetic analyses were based on three concatenated markers, namely 28S and 12S rDNA and COX1 , from six flatworms. The combination of five morphological characters, which involve egg size, gut morphology and size of the attachment hooks, differentiated northern and southern populations of P. xenopodis in South Africa. The multilocus phylogenetic analyses supported these findings, showing a well-supported cluster of northern P. xenopodis . These findings suggest that taxonomic studies of polystomatid flatworms should make use of geographically representative data sets that consider both morphological and molecular evidence. Moreover, the findings demonstrate that the frog host and flatworm parasite exhibit corresponding phylogeographic structuring in the native range. Consequently, the phylogeography of P. xenopodis , both in the native and invasive range of its host, may act as a key piece of evidence to reconstruct past invasion pathways of X. laevis
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