Physaloptera Retusa Research Articles

Parasitism and fluctuating asymmetry in Liolaemus darwinii (Squamata: Liolaemidae) from Argentina

A comparative analysis and investigation of the relationship between the parasite Physaloptera retusa (Physalopteridae) and the fluctuating asymmetry (FA) of the lizard Liolaemus darwinii from Argentina was carried out. In this study, the effect produced by the presence of P. retusa on the symmetry of the heads of lizards has been investigated. Thirty specimens (12 parasitised and 18 non-parasitised) from a population of L. darwinii were examined. The results obtained showed statistical differences in fluctuating asymmetry between parasitised and non-parasitised specimens; the parasitised L. darwinii specimens presented greater head asymmetry compared to the non-parasitised ones, confirming the initial hypothesis. The present study allowed us to consider the analysis of fluctuating asymmetry as a tool that, together with parasites, can be considered and be useful in studies related to reptile populations and in conservation biology.

Untangling the Defiant Taxonomy of Physaloptera (Nematoda: Chromadorea: Spirurida: Physalopteridae) Parasites in Reptiles: An Integrative Approach on the Enigmatic P. retusa Suggests Cryptic Speciation

(1) Background: Although Physaloptera retusa is one of the most widespread species infecting reptiles in the Americas, numerous taxonomic problems and little genetic data are associated with it. To clarify the taxonomy of this species, we used an integrative approach. (2) Methods: Physaloptera retusa-infecting Erythrolamprus typhlus (snake) from the Pantanal wetlands, Brazil, was morphologically and genetically characterised (18S and 28S rDNA; COI mtDNA) and compared with conspecific sequences available in GenBank, from parasites of Tupinambis teguixin (lizard), using species delimitation methods. Type specimens of P. liophis were re-evaluated given its morphological similarities with P. retusa. (3) Results: The morphology of the present specimens was equal to that of P. retusa, in which the only difference from P. liophis was the relative position of the vulva. Species delimitation methods were more accurate for the COI dataset; all of them (except ABGD) indicated interspecificity among P. retusa sequences. However, a lack of morphological data or voucher material, associated with the deposited sequences, prevented more assertive conclusions. (4) Conclusions: The present results highlight the importance of a clear association between genetic data and morphology of the isolation source, or at least its adequate vouchering. Moreover, P. retusa may represent a species complex in cryptic speciation, since it is widespread and has low hosts specificity.

Evaluation of parasitic infections with histological and molecular detection in Anoles from St. Kitts

Anoles are a widely distributed group of reptiles that are also increasing in popularity as a pet animal. These species have been described as paratenic and intermediate hosts for many parasites of veterinary and medical importance. However, while human and animals such as cats and dogs may often interact with anoles, little research has been conducted in terms of assessing the full potential of anoles to harbor parasites of public and veterinary health significance. The current study analyzed the parasites of anoles captured and dissected in St. Kitts, West Indies, to describe the parasitic population within these reptiles and evaluate the potential role of anoles as intermediate/paratenic hosts. From March until May of 2019, samples from 11 anoles were collected following humane euthanasia and evaluated grossly, histologically, and molecularly for the presence of parasites. Histologic evaluation revealed adult ascarids, oxyurids, and spirurids within the stomach, as well as intraluminal adult ascarids within the intestine, and encysted larval trematodes within the intestinal wall. Molecular analysis based on 18S rRNA and ITS2 DNA markers for nematodes and trematodes, respectively, identified Physaloptera sp. (99.4–99.8% identical with Physaloptera turgida, Physaloptera mirandai, Physaloptera retusa, Physaloptera rara) and Platynosomum illiciens (99.7% identical). Phylogenetic analysis of ITS 2 sequences of P. illiciens from this study cladded monophyletically with the same species from different geographic areas and hosts. Our study highlights the importance of understanding the role anoles play in the life cycles of less well-studied parasites, and the potential of these animals to act as intermediate or paratenic hosts.

"Revisiting the past": a redescription of Physaloptera retusa (Nemata, Physalopteridae) from material deposited in museums and new material from Amazon lizards.

Physaloptera Rudolphi, 1819 is a genus of nematodes that includes approximately 100 species parasitic in vertebrates around the world. From these, approximately 30 occur in the Neotropical region, with nine reported from neotropical reptiles. Physaloptera spp. are recognized by their distinct morphology of the apical end and characters of the reproductive system. However, despite the fact that the morphological characters for species diagnosis have been firmly established, we frequently find identification problems regarding poorly detailed descriptions and poorly preserved specimens. These may lead to taxonomic incongruencies. Physaloptera retusa (Rudolphi, 1819) is the most common species of the genus and has been reported from several species of neotropical reptiles. Based on our reexaminations of nematode specimens identified as P. retusa from different museum collections, we provide a detailed redescription including the type material, voucher specimens and new specimens recovered currently and showed in this study with new morphological data obtained using light and scanning electron microscopy tools.

Physaloptera retusa

This datasheet on Physaloptera retusa covers Identity, Distribution, Hosts/Species Affected.

Helminth fauna of Norops fuscoauratus (D'Orbigny, 1837) (Squamata: Dactyloidae) in the Atlantic Forest, northeastern Brazil.

The composition of macro endoparasites associated with the lizard Norops fuscoauratus (Squamata) was analysed in two localities in the Atlantic Forest on the northeast of Brazil between December 2012 and July 2015. 74 specimens of N. fuscoauratus were examined and five species of helminths were reported, being: (a) for the population of Pernambuco: Cystacanth (Prevalence=37.5%), Physaloptera retusa Rudolphi, 1819 (Prevalence=4.16%), larva of flatworm (Prevalence=2.08%), Rhabdias sp. (Prevalence=2.08%) and Strongyluris oscari Travassos, 1923 (Prevalence=2.08%), and (b) of Alagoas: S. oscari (Prevalence=17.85%) and Rhabdias sp. (Prevalence=3.57%). The differences in the composition of endoparasites in the two populations are attributed to individualities of environments occupied by the lizards. The collection period does not influence the abundance of parasites, but when associated with sex, there was a positive correlation with the abundance of helminths, with more females than males being infected with parasites in the rainy season.

A checklist of helminths associated with reptiles (Tetrapoda: Reptilia) from Peru.

An annotated checklist of the helminth parasites associated with reptiles from Peru is provided, as the result of a compilation of parasitological papers published between 1963 and January 2022 and records of species deposited in national and international collections. The list provides data on hosts, developmental stage, sites of infection, geographical distribution in Peruvian territory, code of material deposited in helminthological collections, references and taxonomic notes. The database includes records of 106 different species of helminth parasites (82 nominal species and 24 taxa identified at the generic level), the majority in the adult stage. These helminth parasites come from 18 of the 25 official Peruvian regions. Nematodes have the highest richness in number of species (79 species), followed by trematodes (17 species) and cestodes (nine species). The acanthocephalans are represented by only one species. The parasites with the highest number of records were Physaloptera retusa Rudolphi, 1819 (11 hosts), Physalopteroides venancioi (Lent, Freitas & Proença, 1946) (nine hosts), Strongyluris oscari Travassos, 1923 (seven hosts), and Parapharyngodon scleratus Travassos, 1923 (five hosts), all of which are nematodes. The 106 taxa of helminth parasites have been reported infecting 55 species of reptiles in Peru, distributed in 34 genera and 14 families. The reptile species harbouring the highest number of helminth parasites are the yellow-footed tortoise Chelonoidis denticulatus (Linnaeus) with 18 species (three trematodes and 15 nematodes), followed by the Peru desert tegu Dicrodon guttulatum Duméril & Bibron (Teiidae) with 11 species (three cestodes and eight nematodes) and the yellow-spotted Amazon River turtle Podocnemis unifilis Troschel (Podocnemididae) with 10 species (five trematodes and five nematodes). Of the 524 species of reptiles reported in Peru, only 55 (>10%) are reported as hosts of helminths representing a small proportion considering the great variety of reptile hosts that inhabit the various tropical and subtropical geographical areas of Peru.

Gastrointestinal Helminths of Four Lizard Species (Squamata: Phrynosomatidae and Teiidae) from Mixteca Region, Oaxaca, Mexico

Sixty-eight lizards representing 4 species (Aspidoscelis mexicanus, Sceloporus horridus, Sceloporus ochoterenae, and Urosaurus bicarinatus) collected from the locality of Santiago Tamazola in the Mixteca Region of Oaxaca, Mexico were examined for gastrointestinal helminths. One species of Cestoda, Mesocestoides sp. (tetrathyridium larvae), and 2 species of Nematoda, Physaloptera retusa and Spauligodon garciaprietoi were found. Physaloptera retusa had the highest prevalence (85%) in S. horridus and was found parasitizing all 4 lizard species, and S. garciaprietoi had the most numerous helminth (n = 626) in A. mexicanus. The helminths are generalist and have indirect life cycles with the exception of S. garciaprietoi. We provided new host and distribution records for the 3 helminth species (Mesocestoides sp., P. retusa, and S. garciaprietoi) and present the first helminth reports for S. horridus, S. ochoterenae, and U. bicarinatus. Further, Mesocestoides sp. tetrathyridia is reported for the first time in Oaxaca State. This work contributes to the helminth fauna associated with lizards from Mexico.

Diet and helminth parasites of freshwater turtles Mesoclemmys tuberculata , Phrynops geoffroanus (Pleurodira: Chelidae) and Kinosternon scorpioides (Criptodyra: Kinosternidae) in a semiarid region, Northeast of Brazil

In this study, the Kinosternon scorpioides , Mesoclemmys tuberculata and Phrynops geoffroanus freshwater turtles collected in the Carius River, State of Ceara, were analysed as to their diet composition and presence of helminths. Among the 63 examined turtles 55 (87.3%) were parasitized. We found three Nematoda species ( Physaloptera retusa , Serpinema monospiculatus and Spiroxys figueiredoi ) and one Trematoda species ( Gorgoderina sp.). Phrynops geoffroanus had the highest indexes of prevalence (97.56%) and mean intensity of infection (33.5), followed by M. tuberculata (70% and 12.64, respectively) and K. scorpioides (50% and three, respectively). Host body size was positively related to helminths abundance in both male and female Chelidae species. A significant difference in helminths abundance between the sexes was found only in P. geoffroanus , where females had more parasites than males. Regarding diet, the main food items ingested by M. tuberculata were Odonata nymphs (Aeshnidae and Libellulidae), whilst P. geoffroanus feeds mainly on Diptera larvae (Chironomidae), Odonata nymph (Aeshnidae) and Notonectidae, and only seeds were found in the stomach contents of K. scorpioides . Here, we present the first record of S. monospiculatus parasitizing K. scorpioides , Gorgoderina sp. and P. retusa were reported for the first time in P. geoffroanus , and M. tuberculata represents a new host to P. retusa and S. figueiredoi .

Nematode assemblages associated with the parthenogenetic lizard Ameivula nativo in six restinga areas along the eastern coast of Brazil.

We surveyed the nematode assemblages associated with populations of the parthenogenetic whiptail lizard Ameivula nativo from six coastal restinga areas in eastern Brazil: Setiba, Comboios and Guriri (State of Espirito Santo) and Guaratiba, Prado and Maraú (State of Bahia). A total of five nematode species (Physaloptera retusa, Physalopteroides venancioi, Skrjabinelazia intermedia, Subulura lacertilia and Parapharyngodon sp.) were recorded from the six different populations of A. nativo. There was considerable variation in overall prevalence of infection (1-42%) among study sites, but geographical distance among areas did not influence similarity in the composition of nematode assemblages. Overall intensity of infection was not affected by lizard body size and did not seem to affect host body condition, based on pooled data of all populations. The studied populations of the unisexual A. nativo had relatively low prevalences and intensities of infection compared to some bisexual congeners and to sympatric lizards from other families for which such data are available. We believe that the low richness of the nematode fauna associated with A. nativo, both locally and regionally, may reflect its narrow geographic distribution and the low diversity of habitats it occupies.

Parasitic nematodes of Polychrus acutirostris (Polychrotidae) in the Caatinga biome, Northeastern Brazil.

We present data on nematode infracommunity of the arboreal lizard Polycrhus acutirostris in the semiarid Caatinga biome, northeastern Brazil. Twenty- twolizard specimens collected in the municipality of Várzea Alegre in Ceará State and in the municipality of Exu in Pernambuco State were analyzed. Two species of nematodes were found, an Oxyuridae, Gynaecometra bahiensis, which had a mean intensity of infection 23.5 ± 5.8 (prevalence 22%) and a Physalopteridae, Physaloptera retusa which had infection intensity of 21 (prevalence 9%). There were no significant differences between the parasitism rates of male or female lizards. Polychrus acutirostris demonstrated low richness of nematode parasites, but high levels of infection with G. bahiensis. Polychrus acutirostrisis reported here as a new host for P. retusa.

Intestinal Helminths of the Wandering Grass Lizard,Cnemidophorus gramivagus(Squamata: Teiidae), from Brazil

Cnemidophorus gramivagus from Brazil was examined for helminths. Found were 1 species of Cestoda, Oochoristica freitasi, and 7 species of Nematoda, Amphibiocapillaria freitasilenti, Kentropyxia sauria, Oswaldocruzia vitti, Parapharyngodon senisfaciecaudus, Physaloptera retusa, Spinicauda spinicauda, and Acuariid gen. sp. Seven new host records are recorded. Cnemidophorus gramivagus and other South American teiids are parasitized by generalist helminths that also infect other lizard species. In contrast, North American teiid lizards host helminth species mainly restricted to members of the Teiidae.

Gastrointestinal Nematodes of Four Species of Gonatodes (Squamata: Sphaerodactylidae) from Central and South America

Four species of Gonatodes, Gonatodes albogularis, Gonatodes antillensis, Gonatodes concinnatus, and Gonatodes humeralis, were examined for helminths. Found were 8 species of Nematoda: gravid specimens of Cosmocerca parva, Parapharyngodon scleratus, Physaloptera retusa, Skrjabinelazia galliardi, Spauligodon bonairensis, and Spauligodon oxkutzcabiensis and larvae of Physaloptera sp. and Acuariidae gen. sp. It appears that species of Gonatodes are parasitized by generalist helminths. A list for currently known helminths infecting species of Gonatodes and 4 new host records are provided.

Nematodes of Lizards (Reptilia: Squamata) from Caatinga Biome, Northeastern Brazil

Thirty-one specimens from 7 lizard species (Cnemidophorus ocellifer, Hemidactylus brasilianus, Hemidactylus mabouia, Iguana iguana, Tropidurus hispidus, Tropidurus semitaeniatus, and Phyllopezus pollicaris) captured in 4 localities at the Caatinga biomes from the states of Ceará and Piauí, northeastern Brazil, were surveyed for endoparasites. Eight nematode species (Parapharyngodon sceleratus, Parapharyngodon sp., Physaloptera lutzi, Physaloptera retusa, Physalopteroides venancioi, Rhabdias sp., Spauligodon oxkutzcabiensis, and Strongyluris oscari) were recovered. We report 6 new host records and 7 new locality records.

Occurrence of Helminths in Lizards (Reptilia: Squamata) at Lower Moa River Forest, Cruzeiro do Sul, Acre, Brazil

Eleven of 113 (10%) lizards representing 6 of the 17 species (Anolis fuscoauratus, Anolis trachyderma, Plica umbra, Kentropyx pelviceps, Arthrosaura reticulata, and Mabuya nigropunctata) collected in the lower Moa River forest, in the Amazon rainforest in the Brazilian state of Acre, were infected with helminths in the gastrointestinal tracts. The nematodes recovered from lizards were Physaloptera lutzi, Physaloptera retusa, and Physalopteroides venancioi. Three new host records and two new locality records are reported.

Helminths from Lizards (Reptilia: Squamata) at the Cerrado of Goiás State, Brazil

Forty-three specimens representing 11 species of lizards (Ameiva ameiva, Anolis chrysolepis brasiliensis, Cnemidophorus cf. parecis, Hemidactylus mabouia, Mabuya dorsivittata, Mabuya nigropunctata, Ophiodes striatus, Philautus acutirostris, Tropidurus itambere, Tropidurus oreadicus, and Tupinambis merianae) collected in 6 localities of the Cerrado biome in the Brazilian state of Goiás were examined for helminths. Thirteen species of nematodes (Cruzia travassosi, Gynaecometra bahiensis, Oswaldofilaria sp., Parapharyngodon sp., Parapharyngodon largitor, Parapharyngodon sceleratus, Pharyngodon travassosi, Physaloptera sp., Physaloptera lutzi, Physaloptera retusa, Physalopteroides venancioi, Subulura lacertilia) and an unidentified species of cestode (Oochoristica sp.) were recovered from lizard hosts. Thirteen new host records and 7 locality records are reported.

Functionally opposing effects of testosterone on two different types of parasite: implications for the immunocompetence handicap hypothesis

Summary 1. The immunocompetence handicap hypothesis (ICHH) proposes that androgen‐dependent sexual traits are honest indicators of male quality because androgens are thought to suppress the immune system’s ability to combat parasitic infection. Yet, recent work suggests that the relationship between androgens and parasitism is more complex, as androgens may have different effects on the various types of parasites. 2. We explored this issue in free‐living mountain spiny lizards, Sceloporus jarrovi, by measuring the prevalence of four endoparasite species and one ectoparasite species in castrated, sham‐operated and testosterone (T)‐implanted males. 3. We found that effects of T manipulation accounted for the greatest amount of variability in the abundance of Trombiculid mites and two gastrointestinal nematodes (Physaloptera retusa and Spauligodon giganticus). Plasma T levels were positively associated with mite loads, negatively associated with P. retusa loads and not associated with S. giganticus load. We also found that T treatment had little effect on the abundances of two species of blood‐borne endoparasites (Plasmodium chiricahuae and an unidentified haemogregarine). Instead, the prevalence of these two parasites was mostly influenced by other physiological or seasonal factors, such as corticosterone levels, body condition, fat stores or time between capture events. 4. Our data illustrate that T can have functionally distinct and opposing effects on different parasite species. This finding supports the hypothesis that T does not depress the immune system in a way that causes an across‐the‐board increase in parasitism. 5. We speculate that T modifies select behavioural and physiological factors that govern parasite accumulation. Evolutionarily, our data also imply that the net ‘cost of T’ with respect to elevated ectoparasitism may be at least partially offset by concomitant reductions in helminth load.

Helminths of the teiid lizard Kentropyx calcarata (Squamata) from an Amazonian site in western Brazil

Despite being conspicuous members of neotropical lizard communities, aspects of the life history of many teiid lizard species are poorly known, especially endoparasites infecting the genus Kentropyx. We studied seven specimens of K. calcarata collected at an Amazonian site in Mato Grosso state, Central Brazil in 2007. Four species of helminth were recovered: Oswaldocruzia sp., Piratuba digiticauda, Physaloptera retusa and Physalopteroides venancioi. Piratuba digiticauda, a body-cavity, parasite had the highest prevalence (42.9%), whereas the stomach parasites P. venancioi and P. retusa presented the highest intensity of infection and abundance, respectively. Moreover, this is the first report of Oswaldocruzia sp., P. digiticauda and P. venancioi in K. calcarata and new locality records for all nematodes were assigned.

Gastrointestinal Helminths from Six Species of Frogs and Three Species of Lizards, Sympatric in Pará State, Brazil

Abstract Forty-three frogs representing 6 species (Dendropsophus cachimbo, Scinax fuscomarginatus, Leptodactylus fuscus, Leptodactylus martinezi, Leptodactylus mystaceus, and Leptodactylus rhodomystax) and 35 lizards representing 3 species (Kentropyx calcarata, Leposoma osvaldoi, and Potamites ecpleopus) collected in the Brazilian state of Para were examined for helminths. One species of Trematoda, Brachycoelium salamandrae, and 12 species of Nematoda, adults of Capillaria recondita, Cosmocerca brasiliense, Cosmocerca podicipinus, Falcaustra belemensis, Falcaustra maculata, Kentropyxia sauria, Oswaldocruzia vaucheri, Physaloptera retusa, Schrankiana formulosa, Schrankiana fuscus, Schrankiana schranki, and juveniles of Acuariidae gen. sp., were found. Only B. salamandrae occurred in both frogs and lizards. There were 1.53 ± 0.13 (x ± 1 SE) helminth species/infected frogs and 28.52 ± 11.7 helminth individuals/infected frogs and 1.12 ± 0.08 helminth species/infected lizards and 6.47 ± 1.58 helminth individua...

Isotopic insight into host–endosymbiont relationships in Liolaemid lizards

Nitrogen isotopes have been widely used to investigate trophic levels in ecological systems. Isotopic enrichment of 2-5 per thousand occurs with trophic level increases in food webs. Host-parasite relationships deviate from traditional food webs in that parasites are minimally enriched relative to their hosts. Although this host-parasite enrichment pattern has been shown in multiple systems, few studies have used isotopic relationships to examine other potential symbioses. We examined the relationship between two gut-nematodes and their lizard hosts. One species, Physaloptera retusa, is a documented parasite in the stomach, whereas the relationship of the other species, Parapharyngodon riojensis (pinworms), to the host is putatively commensalistic or mutualistic. Based on the established trophic enrichments, we predicted that, relative to host tissue, parasitic nematodes would be minimally enriched (0-1 per thousand), whereas pinworms, either as commensals or mutualists, would be significantly enriched by 2-5 per thousand. We measured the (15)N values of food, digesta, gut tissue, and nematodes of eight lizard species in the family Liolaemidae. Parasitic worms were enriched 1+/-0.2 per thousand relative to host tissue, while the average enrichment value for pinworms relative to gut tissue was 6.7+/-0.2 per thousand. The results support previous findings that isotopic fractionation in a host-parasite system is lower than traditional food webs. Additionally, the larger enrichment of pinworms relative to known parasites suggests that they are not parasitic and may be several trophic levels beyond the host.