Helminth parasites of Phyllodactylidae and Gekkonidae lizards in a Caatinga ecological station, northeastern Brazil

Metazoan Endoparasites of the Gecko Phyllopezus periosus (Squamata: Phyllodactylidae) Inhabiting the Rock Cliffs of a Waterfall Canyon in the Semi-Arid Region from Northeastern Brazil

PURPOSE

This study describes the composition and infection patterns of macro endoparasites associated with the lizard Phyllopezus periosus.

METHODS

We collected 115 P. periosus over 12 expeditions on the rocky cliffs of the Missão Velha waterfall canyon in northeastern Brazil. Specimens were collected by hand, during active searches conducted between 18:00 h and 23:30 h. The infection patterns were estimated using prevalence, total abundance, and mean intensity of infection for all parasites found.

RESULTS

A total of 4256 parasites were collected from 104 hosts, resulting in an exceptionally high overall prevalence of 90.4%. No significant ontogenetic difference in the prevalence of infection was detected. Although juveniles exhibited a high parasite prevalence their parasite loads were significantly lower compared to adults. Six species of endoparasites were found; among these, the nematode Spauligodon oxkutzcabiensis was the most common endoparasite in the digestive tract, while the pentastomid Raillietiella mottae was the only species found in the respiratory tract.

CONCLUSIONS

Infection rates in Gekkota species appear to correlate with body size, with larger individuals generally exhibiting a higher prevalence. This pattern was also observed across separate populations of P. periosus and other geckos from distinct ecological domains. The dominance of the monoxenous S. oxkutzcabiensis highlights potential transmission mechanisms, suggesting that behaviors such as limb licking after feeding may contribute to its prevalence. The occurrence of Physalopteroides venancioi, Oswaldocruzia sp., Parapharyngodon sp., Physaloptera sp., infecting P. periosus are new records for this host. These findings significantly contribute to the knowledge of host-parasite dynamics in geckos.

Checklist of parasites associated with 'reptiles' in Northeast Brazil

Reptiles, as well as other vertebrate groups, harbour a significant diversity of parasitic organisms, from nematodes and other helminths to viruses and bacteria. The Northeast is one of the richest regions in Brazil in terms of the reptile diversity, number of species and endemism. Parasites are diverse organisms and knowledge about the parasitic fauna of vertebrates is an important factor in understanding the ecological relationships between hosts and the environment. Studies on the parasitic fauna of reptiles in South America have increased in the past few years. The present review is a compilation of 122 studies published from 1924 to 2021. We present information on 101 species of reptiles from five groups (amphisbaenians, crocodile, testudines, snakes and lizards) and 183 parasitic taxa belonging to four phyla: Nematoda; Arthropoda; Platyhelminthes; and Acanthocephala. Nematodes were the most frequently recorded species. Lizards and snakes had more records of parasitism and higher levels of parasite richness and diversity. Ceará was the state with most studies and recorded cases of parasite-host association. The Caatinga and Atlantic Forest were the most investigated environments. The objective of this review was to contribute knowledge on the parasitic biodiversity in reptiles from Northeast Brazil, which may help identify gaps in our knowledge and guide future studies.

HELMINTH FAUNA OF THECADACTYLUS RAPICAUDA (HOUTTUYN, 1782) (SQUAMATA, PHYLLODACTYLIDAE) IN THE CAXIUANÃ NATIONAL FOREST, FROM THE BRAZILIAN EASTERN AMAZON

The Amazon region is an important region for biodiversity, and many new species are described for this region each year. However, the diversity of parasites infecting Amazonian reptiles is still poorly known, and there are few studies about how parasite communities of these hosts are structured. Our study was designed to elucidate the parasite community structure of Thecadactylus rapicauda, one of the largest species of gekkonid lizards in the world, and to discover the relative utility of size, sex, and body mass of Thecadactylus rapicauda as predictive factors of the abundance of helminth parasites. We analyzed 40 individuals of T. rapicauda, of which 34 had parasites (85% of prevalence), with 269 specimens allocated to 10 species. Body size of the host showed a positive influence on the abundance of helminths. Host sex is another important factor related to the abundance of nematodes: females were usually heavily infected. We conclude that T. rapicauda has a high richness of the helminth species and that most of the species found infecting this host were nematodes with a direct life cycle. Additionally, we found new helminth species, which should be described formally in the future.

Helminths Infecting Dryadosaura Nordestina (Squamata: Gymnophthalmidae) from Atlantic Forest, Northeastern Brazil

We analyzed the patterns of infection by helminths in populations of the Gymnophthalmidae lizard Dryadosaura nordestina from three Atlantic Forest fragments in Northeast Brazil. Prevalence and mean intensity of infection by location showed the following results: ARIE Mata de Goiamunduba (60.8 % and 10.4 ± 8), RPPN Engenho Gargaú (83.3 % and 20.8 ± 19.7) and Benjamim Maranhão Botanical Garden (70.4 % and 7.78 ± 5.8). We provide the first records of helminth infection for the lizard D. nordestina, in which three species of nematodes, Aplectana sp., Cosmocerca sp. and Physaloptera lutzi and one trematode Haplometroides odhneri were recovered. Trematodes of the genus Haplometroides were previously known as parasites only in snake and amphisbaenian hosts in South America. Now, our study provides the first record of a species belonging to this genus parasitizing lizards. In conclusion, our study shows that D. nordestina have a depleted helminth fauna (three species at maximum), similar to other studies with lizards of this family in Brazil and that its parasite abundance is related to host snout-vent length, but not to the sex.

Parasites of Gymnodactylus darwinii Gray, 1845 (Squamata, Phyllodactylidae) from an Atlantic Rainforest fragment

Gymnodactylus darwinii is an endemic lizard from Atlantic Rainforest. Ecological aspects of your parasitic fauna are still unknown. Therefore, the goal of the present study was to know the composition of parasitic fauna of G. darwinii in an Atlantic Rainforest fragment, as well to test the influence of the size, sex and seasonality on parasitological indices. The study was carried out in two conservation units: Mata do Camucim and Mata do Tapacurá, both located in the municipality of São Lourenço da Mata, Pernambuco state, northeast region of Brazil. Sixty-five specimens were collected, of which 39 (569%) were parasitized by cystacanths of Acanthocephala (prevalence 43%; mean intensity 4 ± 9.9; mean abundance 3.82 ± 7.87), Geckobia sp. (Acari, Pterygosomatidae) (prevalence 30.7%; mean intensity 4 ± 15.0; mean abundance 3.74 ± 9.54), Physaloptera sp. larvae (Nematoda, Physalopteridae) (prevalence 4.6%; mean intensity 1 ± 0.47; mean abundance 0.06 ± 0.47) and Paradistomum rabusculum (Trematoda, Dicrocoeliidae) (prevalence 1.2%; mean intensity 1; mean abundance 0.02). Acanthocephalans presented a significant relation with the animal length (r² = 0.31, p = 0.006, n = 28). Infestation by Geckobia sp. was more frequent during the dry season (BLM: p = 0.001), while the infection by Acanthocephalans was frequent in dry and rainy seasons, with no significant variation (BLM: p = 0.78). In addition, the most prevalent parasites showed no significant difference in relation to sex: males and females showed similar infestation intensity by Geckobia sp. (BLM: p = 0.31) and infection by Acanthocephala (BLM: p = 0.34). This is the first study about the parasitic ecology of G. darwinii, representing a significant contribution to the conservation of this species and the ecosystem in which they inhabit.

Helminth Fauna of Valentin's Lizard Darevskia Valentini (Boettger, 1892) (Squamata: Lacertidae) Collected from Central and Eastern Anatolia, Turkey

In this study, we assessed the helminth fauna of seventy two Valentin's Lizard, Darevskia valentini (32♂♂, 35 ♀♀, 5 subadult). Specimens collected from Kayseri, Ardahan and Van Provinces in Turkey. As a result of the present study, it was detected that forty one hosts are infected with one or more species of helminth. Two species of Cestoda, Oochoristica tuberculata and Mesocestoides spp., and 5 species of Nematoda, Spauligodon aloisei, Skrjabinodon alcaraziensis, Skrjabinodon medinae, Skrjabinelazia hoffmanni and Strongyloides darevsky were found in the hosts. D. valentini represents a new host record for all helminths recorded. Skrjabinodon alcaraziensis is recorded for the first time from Turkey. Van, Kayseri and Ardahan are new locality records for all helminths from D. valentini.

Helminth Parasites of the Lizard Nothobachia ablephara (Gymnophthalmidae) in Caatinga Areas from the Sertão of Brazil

The lizard Nothobachia ablephara is endemic to dune areas and sandy soils adjacent to the São Francisco River in semiarid northeastern Brazil. Forty-nine lizard specimens were collected in 2 Caatinga areas in the municipality of Petrolina in Pernambuco state. Three gastrointestinal helminth taxa were identified, the nematodes Parapharyngodon alvarengai and Physaloptera sp. and the cestode Oochoristica sp. Nothobachia ablephara showed low parasite richness, but high levels of infection by P. alvarengai. There were no significant differences between the parasitism rates of the 2 study areas or between male and female lizards. This is the first study on parasitism in N. ablephara, thereby increasing knowledge of parasite fauna that infect gymnophthalmid lizards in the Sertão of Brazil.