Parasites Of Reptiles Research Articles

Postfire biodiversity database for eastern Iberia

In the summer of 2012, two fires affected Mediterranean ecosystems in the eastern Iberian Peninsula. The size of these fires was at the extreme of the historical variability (megafires). Animals are traditionally assumed to recolonize from source populations outside of the burned area (exogenous regeneration) while plants recover from endogenous regeneration (resprouting and seeding). However, there is increasing evidence of in situ fire survival in animals. To evaluate the effect of large-scale fires on biodiversity and the mechanism of recovery, in 2013, we set up 12 plots per fire, covering burned vegetation at different distances from the fire perimeter and unburned vegetation. In each plot, we followed the postfire recovery of arthropods, reptiles (including some of their parasites), and plants for 2 to 5 years. Here we present the resulting database (POSTDIV) of taxon abundance. POSTDIV totals 19,906 records for 457 arthropod taxa (113,681 individuals), 12 reptile taxa (503 individuals), 4 reptile parasites (234 individuals), and 518 plant taxa (cover-abundance). We provide examples in the R language to query the database.

Molecular characterization of haemosporidian and haemogregarine diversity in southwestern Iberian amphibians and reptiles

The knowledge of the diversity and geographic distribution of parasite species is the first step towards understanding processes of global epidemiology and species conservation. Despite recent increases in research on haemosporidian and haemogregarine parasites of reptiles and amphibians, we still know little about their diversity and parasite-host interactions, especially in the Iberian Peninsula, where a few studies have been conducted. In this study, the haemosporidian and haemogregarine diversity and phylogenetic relationships of the parasites in southwestern Iberian amphibians and reptiles were assessed using PCR approaches on blood samples of 145 individuals from five amphibian and 13 reptile species. The amphibians did not present any of both groups of parasites studied. Regarding reptiles, five Hepatozoon, one Haemogregarina, and one Haemocystidum haplotypes were found infecting four different species, revealing new host records for these parasites. Among them, we found one new Haemocystidium haplotype and three new and a previously reported Hepatozoon haplotype from a north African snake. The latter finding suggests that some Hepatozoon parasites may not be host-specific and have large geographic ranges even crossing geographical barriers. These results increased the knowledge about the geographic distribution and the number of known host species of some reptile apicomplexan parasites, highlighting the great unexplored diversity of them in this region.

A Unique Disease Presentation Associated with a Mesomycetozoean-Like Organism in the Jeweled Chameleon (Furcifer campani)

Recent evidence suggests that lizards of the family Chamaeleonidae are one of the most heavily parasitized groups of reptiles kept in captivity; however, little is known about the clinical implications of these infections. Relative to other host species, there is a paucity of information on reptile parasites, and the breadth of parasites that infect chameleons is not well-described. Here, we report a parasitic infection most consistent with organisms belonging to the Mesomycetozoea group, in male and female wild-caught jeweled chameleons (Furcifer campani). Clinical features of infection included persistent weight loss despite increased food intake, cachexia, abnormally increased light- and heat-seeking behavior, coelomic distention, and loose, watery stools. Histologically, there was extensive granuloma formation present in the liver and widespread localization of PAS- and GMS-positive spores resembling those of Dermocystidium sp. in the bone marrow, gastrointestinal tract, and other tissues. A second case of infection with this pathogen also presented with concurrent Mycobacterium sp. throughout the body, suggesting that infection with Mesomycetozoean organisms may serve as a primary cause of death; or conversely, may render the infected individual susceptible to secondary, opportunistic infection. The rapid health decline associated with infection in these cases argues for the need to better characterize prevalence and pathogenicity of parasites in captive chameleons.

Candidatus Neoehrlichia mikurensis and Hepatozoon sp. in voles (Microtus spp.): occurrence and evidence for vertical transmission

Candidatus Neoehrlichia mikurensis (CNM) and Hepatozoon spp. are important vector-borne parasites of humans and animals. CNM is a relatively recently discovered pathogen of humans. Hepatozoon are parasites of reptiles, amphibians and mammals, commonly found in rodents and carnivores worldwide. The present study aimed to determine the prevalence of CNM and Hepatozoon spp. in three species of Microtus and to assess the occurrence of vertical transmission in naturally-infected voles. Molecular techniques were used to detect pathogen DNA in blood and tissue samples of captured voles and their offspring. The prevalence of CNM in the vole community ranged 24–47% depending on Microtus species. The DNA of CNM was detected in 21% of pups from three litters of six infected Microtus dams (two Microtus arvalis and one M. oeconomus) and in 3/45 embryos (6.6%) from two litters of eight CNM-infected pregnant females. We detected Hepatozoon infection in 14% of M. arvalis and 9% of M. oeconomus voles. Hepatozoon sp. DNA was detected in 48.7% of pups from seven litters (6 M. arvalis and 1 M. oeconomus) and in two embryos (14.3%) obtained from one M. arvalis litter. The high prevalence of CNM infections in the Microtus spp. community may be a result of a relatively high rate of vertical transmission among naturally infected voles. Vertical transmission was also demonstrated for Hepatozoon sp. in M. arvalis and M. oeconomus. Our study underlines the significance of alternative routes of transmission of important vector-borne pathogens.

Morphometric and molecular characterization of an unpigmented haemosporidian parasite in the Neotropical turnip-tailed gecko (Thecadactylus rapicauda).

Morphological traits from blood stages have been the gold standard for determining haemosporidian parasite species. However, the status of some taxa and the value of such traits in parasites from reptiles remain contentious. The scarce sampling of these species worsens the situation, and several taxa lack molecular data. A survey was performed in the Magdalena Department in Colombia, where 16 species of reptiles were captured. A peculiar haemosporidian parasite was found in the Turnip-tailed gecko Thecadactylus rapicauda. This haemosporidian does not show malarial pigment in blood stages under light microscopy; thus, it fits the Garnia genus's characters belonging to the Garniidae. However, the phylogenetic analyses using a partial sequence of cytochrome b and the mitochondrial DNA placed it within the Plasmodium clade. Our findings suggest that many putative Garnia species belong to the genus Plasmodium, like the one reported here. This study either shows that visible malarial pigment in blood stages is not a diagnostic trait of the genus Plasmodium or malarial pigment might be present in an undetectable form under a light microscope. In any case, the current taxonomy of haemosporidian parasites in reptiles requires revision. This study highlights the importance of using molecular and morphological traits to address taxonomic questions at the species and genus levels in haemosporidian parasites from reptiles.

Experimental infections of sand flies and geckos with Leishmania (Sauroleishmania) adleri and Leishmania (S.) hoogstraali

BackgroundSpecies belonging to the subgenus Sauroleishmania are parasites of reptiles, and traditionally considered to be non-pathogenic to mammals. Knowledge of the development of these parasites in sand flies and their mechanism of transmission is currently lacking. The main aim of this study was to test the susceptibility of various sand fly species to infection by two Sauroleishmania species, focusing on the localization of parasites in the sand fly intestinal tract.MethodsThe development of Leishmania (Sauroleishmania [S.]) adleri and Leishmania (S.) hoogstraali was studied in six sand fly species (Phlebotomus orientalis, P. argentipes, P. sergenti, P. papatasi, P. duboscqi, Sergentomyia schwetzi). Sand flies were fed through a chick-skin membrane on blood containing Sauroleishmania promastigotes, and they were dissected at various time intervals post blood meal (PBM). Guts were examined microscopically for the presence of parasites, and the intensity and localizations of infections were recorded. Morphological forms of both Sauroleishmania species developing in P. orientalis were analyzed. Experimental infections of geckos using sand fly-derived promastigotes were also performed, and the reptiles were repeatedly examined for Sauroleishmania infection by xenodiagnosis and PCR analysis.ResultsHigh infection rates for both Sauroleishmania species were observed in P. orientalis and P. argentipes, with the parasites migrating anteriorly and undergoing a peripylarian type of development, including colonization of the stomodeal valve. Conversely, the development of L. (S.) adleri in P. sergenti, P. papatasi and Se. schwetzi was restricted to the sand fly hindgut (hypopylarian type of development). Five morphological forms were distinguished for both Sauroleishmania species developing in P. orientalis. All experimentally infected geckos scored negative for Sauroleishmania based on xenodiagnosis and molecular analysis.ConclusionsThe results showed that Sauroleishmania promastigotes can undergo either a peripylarian or hypopylarian type of development in the sand fly intestinal tract, depending on the sand fly species infected. We demonstrated that P. argentipes and P. orientalis, two sand fly species known as permissive vectors for mammalian parasites of subgenus Leishmania, are also highly susceptible to Sauroleishmania as the parasites developed mature late-stage infections, including colonization of the sand fly stomodeal valve. Thus, the role of Phlebotomus sand flies in transmission of Sauroleishmania should be reconsidered and further investigated.Graphical

Automatic identification of intestinal parasites in reptiles using microscopic stool images and convolutional neural networks.

Captive environments trigger the propagation and multiplication of parasites among different reptile species, thus weakening their immune response and causing infections and diseases. Technological advances of convolutional neural networks have opened a new field for detecting and classifying diseases which have shown great potential to overcome the shortcomings of manual detection performed by experts. Therefore, we propose an approach to identify six captive reptiles parasitic agents (Ophionyssus natricis, Blastocystis sp, Oxiurdo egg, Rhytidoides similis, Strongyloides, Taenia) or the absence of such parasites from a microscope stool images dataset. Towards this end, we first use an image segmentation stage to detect the parasite within the image, which combines the Contrast Limited Adaptive Histogram Equalization (CLAHE) technique, the OTSU binarization method, and morphological operations. Then, we carry out a classification stage through MobileNet CNN under a transfer learning scheme. This method was validated on a stool image dataset containing 3616 images data samples and 26 videos from the six parasites mentioned above. The results obtained indicate that our transfer learning-based approach can learn a helpful representation from the dataset. We obtained an average accuracy of 94.26% across the seven classes (i.e., six parasitic agents and the absence of parasites), which statistically outperformed, at a 95% confidence level, a custom CNN trained from scratch.

A new tapeworm from Compsophis infralineatus (Pseudoxyrhophiidae), an endemic snake of Madagascar: Scratching the surface of undiscovered reptilian parasite diversity.

A new species of proteocephalid cestodes, provisionally assigned to the polyphyletic genus Ophiotaenia La Rue, 1911 (Cestoda: Proteocephalidae), is described from Compsophis infralineatus (Günther) (Serpentes: Pseudoxyrhophiidae) endemic to Madagascar. Ophiotaenia oreae n. sp. differs from all African and Asian species of Ophiotaenia by possessing more uterine diverticula (68-82 on one side). It is also characterised by the absence of an apical organ, the relative sizes of the cirrus-sac and ovary, the almost equatorial position of the gonopore, the diameter of the embryophore, and other biometric characteristics. Phylogenetic relationships of the new species indicate its relatedness to Indomalayan and Australasian proteocephalids from reptiles. Ophiotaenia oreae n. sp. formed a well-supported clade composed of species of Australophiotaenia de Chambrier, Beveridge and Scholz, 2018 from Australian snakes, Macrobothriotaenia ficta (Meggitt, 1931) from Xenopeltis unicolor Reinwardt in Boie from Vietnam, Ophiotaenia sp. from Trimeresurus flavomaculatus (Gray) from the Philippines, and Ophiotaenia bungari de Chambrier, Binh and Scholz, 2012 from Bungarus fasciatus (Schneider) from Vietnam. The only proteocephalid from Madagascan snakes sequenced so far, Ophiotaenia lapata Rambeloson, Ranaivoson and de Chambrier, 2012 from Madagascarophis colubrinus (Schlegel), does not form a monophyletic group with the new species. The actual species diversity of reptilian cestodes in Madagascar is undoubtedly underestimated. Because of the assumed strict (oioxenous) host specificity of reptilian proteocephalids and rich fauna of snakes occurring in Madagascar, it is plausible to expect the existence of dozens new species of proteocephalids on this island.

Gastrointestinal parasites in wild and exotic animals from a Zoobotanical Park in Northeast of Brazil

One of the obstacles for ex situ conservation of wild and exotic animals are the diseases that affect them in captivity and, among them, the endoparasitoses, which are very frequent. The objective of this study is to report the occurrence of endoparasites in the fecal samples of animals from the Arruda Câmara Zoobotanical Park, at João Pessoa, Paraiba State, Brazil, as well as to identify significant statistical differences between the percentages of each parasite species found. To this end, 66 fecal samples were obtained from 50 species of animals including mammals, birds, and reptiles. Statistical differences between the percentages of each parasite species were obtained using the binomial test at 5% significance level. A total of 54.5% (36/66) of the fecal samples were positive (p=0.539), among which 80.5% (29/36) presented nematodes, followed by cestodes 19.4% (07/36), protozoans 13.9% (05/36), and mites 16.7% (06/36). This study reports for the first time the association of Balantidium sp. with Tapirus terrestris, Bertiella sp. with Alouatta caraya, Hymenolepis spp., and Aspiculuris spp. as spurious parasites in reptiles; and Entamoeba coli and Eimeria spp. with Iguana iguana in the northeastern part of the country. This study provides knowledge about some of the endoparasites that may occur in zoos in the northeastern region of the country, as well as in expanding the ecological data on wild and exotic animals.

Protein Phosphatase PP2C Identification in Entamoeba spp.

Entamoeba histolytica is the causative agent of amoebiasis, and Entamoeba dispar is its noninvasive morphological twin. Entamoeba invadens is a reptilian parasite. In the present study, Western blot, phosphatase activity, immunofluorescence, and bioinformatic analyses were used to identify PP2C phosphatases of E. histolytica, E. dispar, and E. invadens. PP2C was identified in trophozoites of all Entamoeba species and cysts of E. invadens. Immunoblotting using a Leishmania mexicana anti-PP2C antibody recognized a 45.2 kDa PP2C in all species. In E. histolytica and E. invadens, a high molecular weight element PP2C at 75 kDa was recognized, mainly in cysts of E. invadens. Immunofluorescence demonstrated the presence of PP2C in membrane and vesicular structures in the cytosol of all species analyzed. The ~75 kDa PP2C of Entamoeba spp. shows the conserved domain characteristic of phosphatase enzymes (according to in silico analysis). Possible PP2C participation in the encystation process was discussed.

PARÁSITOS EN REPTILES DEL CENTRO DE CONSERVACIÓN Y REHABILITACIÓN DE ANIMALES DE VIDA SILVESTRE DE UNA UNIVERSIDAD PÚBLICA-BRASIL

The medical clinic for reptiles has grown in recent years, whether by attending free-living animals in rehabilitation centers or by acquiring them as pets. The knowledge of the parasitic fauna of the Reptilia Class is important for the identification of pathogenic agents and effective therapy. Fecal samples were collected from 35 animals of the Orders Crocodylia (N=3), Squamata (N=3) and Testudines (N=29) attended from 2013 to 2018 at the Center for Conservation and Rehabilitation of Wild Animals (PRESERVAS) of the Universidade Federal do Rio Grande do Sul (UFRGS). Fecal samples were processed by the methods of Willis, Lutz and Sheather at the Laboratory of Helminthology at UFRGS. The percentage of positive samples was 17.14% (6/35): three Trachemys dorbogni (Dumeril & Bibron 1835) presenting Serpinema spp., Physaloptera spp. and Strongyloidea, respectively; two Caiman latirostris (Daudin, 1802) with Strongyloides spp. and Augusticaecum spp., respectively, and Iguana iguana (Linnaeus, 1758) with Eimeria spp. This study expands the list of parasites in reptiles from the state of Rio Grande do Sul.

Ultra-structural analysis and morphological changes during the differentiation of trophozoite to cyst in Entamoeba invadens

Entamoeba histolytica, a pathogenic parasite, is the causative organism of amoebiasis and uses human colon to complete its life cycle. It destroys intestinal tissue leading to invasive disease. Since it does not form cyst in culture medium, a reptilian parasite Entamoeba invadens serves as the model system to study encystation. Detailed investigation on the mechanism of cyst formation, information on ultra-structural changes and cyst wall formation during encystation are still lacking in E. invadens. Here, we used electron microscopy to study the ultrastructural changes during cyst formation and showed that the increase in heterochromatin patches and deformation of nuclear shape were early events in encystation. These changes peaked at ∼20 h post induction, and normal nuclear morphology was restored by 72 h. Two types of cellular structures were visible by 16 h. One was densely stained and consisted of the cytoplasmic mass with clearly visible nucleus. The other consisted of membranous shells with large vacuoles and scant cytoplasm. The former structure developed into the mature cyst while the latter structure was lost after 20 h, This study of ultra-structural changes during encystation in E. invadens opens up the possibilities for further investigation into the mechanisms involved in this novel process.

A Checklist of Macronyssid Species (Mesostigmata: Macronyssidae) From Brazil.

Macronyssid mites are parasites of reptiles, birds, and mammals. A checklist of macronyssid species of Brazil is provided, containing 13 genera and 26 species collected from 99 host species.

A phylogenetic study of Haemocystidium parasites and other Haemosporida using complete mitochondrial genome sequences.

Haemosporida are diverse vector-borne parasites associated with terrestrial vertebrates. Driven by the interest in species causing malaria (genus Plasmodium), the diversity of avian and mammalian haemosporidian species has been extensively studied, relying mostly on mitochondrial genes, particularly cytochrome b. However, parasites from reptiles have been neglected in biodiversity surveys. Reptilian haemosporidian parasites include Haemocystidium, a genus that shares morphological features with Plasmodium and Haemoproteus. Here, the first complete Haemocystidium mitochondrial DNA (mtDNA) genomes are studied. In particular, three mtDNA genomes from Haemocystidium spp. sampled in Africa, Oceania, and South America, are described. The Haemocystidium mtDNA genomes showed a high A+T content and a gene organization, including an extreme fragmentation of the rRNAs, found in other Haemosporida. These Haemocystidium mtDNA genomes were incorporated in phylogenetic and molecular clock analyses together with a representative sample of haemosporidian parasites from birds, mammals, and reptiles. The recovered phylogeny supported Haemocystidium as a monophyletic group apart from Plasmodium and other Haemosporida. Both the phylogenetic and molecular clock analyses yielded results consistent with a scenario in which haemosporidian parasites radiated with modern birds. Haemocystidium, like mammalian parasite clades, seems to originate from host switches by avian Haemosporida that allowed for the colonization of new vertebrate hosts. This hypothesis can be tested by investigating additional parasite species from all vertebrate hosts, particularly from reptiles. The mtDNA genomes reported here provide baseline data that can be used to scale up studies in haemosporidian parasites of reptiles using barcode approaches.

Parasites of panther chameleons (Furcifer pardalis) grown in captivity and brought from the wild

Reptile parasites imported from the wild differ from those grown in captivity. Thus, captive-grown reptiles tolerate the process of disadaptation better than imported wild animals, even under proper conditions of keeping and feeding. It should be noted that determining the origin of reptiles is sometimes difficult or impossible. For this, special methods are needed. In this regard, the purpose of research was to confirm or refute the theory, in reptiles from different places of residence, various parasites are found. We studied panther chameleons (Furcifer pardalis) imported from the wild and raised in captivity. To determine the parasites in the laboratory, methods of native smear, sequential washing and flotation were used. 10 species of intestinal parasites were found in panther chameleons imported from the wild, in particular Trematoda gen. sp. 1, Tremaitoda gen. sp. 2, Cestoda gen. sp., Spinicauda freitasi (Olfers, 1919), Hexametra angusticaecoides (Chabaud et Brygoo, 1960), Pharyngodonidae gen. sp., spirurates of the genus Thubunaea sp., larvae of the family Rhabdiasidae gen. sp., flagellates from the series Kinetoplastida gen. sp. and Eimeria sp, with prevalence 87.56%. In panther chameleons grown in captivity only Pharyngodonidae gen. sp. was found, prevalence was 94.05%. It is noted that under appropriate conditions of keeping and feeding in captive panther chameleons, a small number of parasites with a direct development cycle and their insignificant toxic effect on the body can develop

Survey of Helminth Parasites in Reptiles under Captivity

Parasitic infections are widespread among reptiles and may cause serious problems. Any data on its prevalence may be useful for their health management in captivity. Hence, a survey through faecal sample examination was conducted to assess the helminth fauna in captive reptiles [Caiman crocodile (Caiman latirostris), Bengal monitor lizard (Varanus bengalensis) and Stared tortoise (Geochelone elegans)], maintained at Bannerghatta Biological Park, Bengaluru, Karnataka. A total of 23 faecal samples from apparently healthy Caiman crocodiles, 6 Bengal monitor lizards and 240 stared tortoises were collected over a period of 12 months during 2015–2016 and were screened using prescribed floatation and sedimentation technique followed by microscopic identification of eggs. We could detect ova of 6 (26.08%) Physaloptera sp. in Caiman crocodile, 3 (50%) Physaloptera sp. in Bengal monitor lizard and 157 (65.41%) oxyurid pinworms in stared tortoise. Upon necropsy, Physaloptera worms were recovered from the stomach of Bengal monitor lizard and pinworms from the stomach and intestine of stared tortoise. This study contributes to our knowledge on prevalence of parasites in the said reptiles in captivity.

Some internal parasites of reptiles in Alexandria Province,Egypt.

For the time being, a growing number of exotic reptiles are kept as pets. Pet reptiles are often infected with parasites, some of which are potentially dangerous to humans. A total of 115 samples from reptile species (Wedge-Snouted skink, African Chameleon, Egg eating snake and Egyptian tortoise) were collected for examination. The results indicated that (48.7%) out of 115 infected with internal parasites .A wide range of internal parasites were detected including nematodes, cestodes and protozoa. Wedge-snouted skink showed the highest infection rate where it reached 82.3%, followed by African Chameleon (51.5%), Egg eating snake (23%) and Egyptian tortoise (22.7%). Various parasites were detected including Strongylid eggs, Spirurid eggs, Heterakid eggs, Oxyurid eggs, eggs of mites, Nyctotherus cysts, Cryptosporidium oocysts, Thelandros spp., Parapharyngodon spp., Raillietascarisvarani, Physaloptera tupinambae, Meteterakis saotomensis and Oochoristica spp.These results revealed that a routine parasitological examination should be done in such animals.

Tapeworms (Cestoda: Proteocephalidae) of Australian reptiles: hidden diversity of strictly host-specific parasites.

Reptilian fauna of Australia is extraordinarily rich and diverse, but very little is known about parasites of reptiles, including proteocephalid cestodes of the genus Ophiotaenia La Rue, 1911. In the present survey, data on these parasites are summarised for the first time based on detailed evaluation of all available type and voucher specimens. This survey includes five named species, with four species redescribed, namely O. amphiboluri (Nybelin, 1917), O. longmani Johnston, 1916, O. mjobergi (Nybelin, 1917), and O. striata (Johnston, 1914), and 9 putative new species which are not formally described because of their poor quality and scarce material. An identification key is given for the five named species and unnamed species are briefly characterised with focus on their differential characteristics to facilitate their description as new taxa in the future. Australian species of Ophiotaenia form a monophyletic lineage, whose members share several morphological traits which are absent or rare in other proteocephalids, such as a three-layered embryophore, a scolex with large, anteriorly directed suckers, eggs with thick-walled embryophores, exclusively dorsal and paramuscular position of vitelline follicles, and a postequatorial to equatorial genital pore in most species. A new genus, Australophiotaenia, is proposed to accommodate the species from Australian reptiles that share the above-mentioned characters.

First detection of Leishmania donovani in sand flies from Cameroon and its epidemiological implications.

A sound knowledge of the vector-host-parasite transmission dynamics is a prerequisite for adequate control measures of vector-borne diseases. To achieve this, an entomological investigation was conducted in the cutaneous leishmaniasis (CL) endemic focus of Mokolo District, northern Cameroon to identify the insect vector(s) of the disease. Phlebotomine sand flies were collected in and around Mokolo using New Standard CDC Miniature Light Traps. Individual sand flies were used for morphological species identification, and the remainder of the body for DNA analysis. Sand flies were demonstrated to harbour Leishmania spp. parasites using ITS1 PCR. Mitochondrial vertebrate-specific Cytochrome b -PCR was used to identify blood meals ingested by female sand flies. PCR amplicons were sequenced for Leishmania and blood sources discrimination. This study revealed the presence of Leishmania donovani complex DNA (n = 1) in Phlebotomus duboscqi and of lizard-borne Leishmania tarentolae-like DNA (n = 3) in Sergentomyia spp. in 79 sand fly specimens from Mokolo district. The causative agent of CL could not be detected in potential vectors. Instead, we found evidence for visceral leishmaniasis (VL) parasites in Phlebotomus duboscqi as well as enzootic reptile parasites in the Mokolo area. We recommend that an epidemiological survey be carried out in the area to evaluate the prevalence and eventually describe the clinical manifestations of VL in the human population. Political instability in neighbouring countries and the resulting refugee migration are likely explanations for the emergence of VL in Mokolo.

Integrative approach on Pharyngodonidae (Nematoda: Oxyuroidea) parasitic in reptiles: Relationship among its genera, importance of their diagnostic features, and new data on Parapharyngodon bainae.

The first integrative approach using sequences of two genes (18S and 28S rRNA) plus morphological and life history traits, was explored in Pharyngodonidae nematodes parasitic in reptiles. Additionally, first genetic characterization of Parapharyngodon bainae and new data on its morphology are given. This approach evaluated the phylogenetic relationships among genera within Pharyngodonidae, as well as the importance of their diagnostic morphological features. Specimens of P. bainae were collected from faecal pellets of the lizard Tropidurus torquatus in the State of Minas Gerais, Brazil. Nematodes were fixed for scanning electron microscopy and molecular procedures. Morphological observations revealed the accurate structures of cephalic end, of cloacal region in males, of vulva and eggs. Phylogenetic reconstructions were based upon four datasets: aligned sequences of the 18S, of the 28S, of both concatenated genes and of combined morphological and molecular datasets. Bayesian inference and maximum likelihood were performed to infer the phylogenies of molecular datasets and maximum parsimony to infer that of all-combined data. Pharyngodonid parasites of reptiles seem to configure two general monophyletic lineages, as previously assertions. Results also showed the monophyly of Spauligodon, Skrjabinodon and Parapharyngodon, as well as the clear separation between the latter and Thelandros. Combination of datasets improved nodal supports. Analysis of the all-combined datasets revealed the importance of vulval position and egg morphology as phylogenetic informative traits. However, characters of male caudal morphology appear as are highly homoplastic, and seem to be product of convergent evolution or multiple losses of ancestral traits. The closely-related Thelandros and Parapharyngodon are kept valid and their diagnosis should be based upon the position of the operculum in eggs (terminal or subterminal, respectively). Some inconsistencies in the scarce molecular and morphological databases were noted. Thus, new genetic data is required for further conclusions and current database must be evaluated with attention.