Waltécio Oliveira Almeida

Hosts function as ecological islands for endoparasites, offering structured habitats that support parasite survival, growth, and reproduction. Larger and older hosts are often expected to harbour more diverse and abundant parasitic assemblages due to increased structural complexity and longer exposure times. In this study, we investigated how host body size and phylogenetic relatedness influence endoparasite mean richness and mean intensity of infection in lizards from the Atlantic Rainforest of northeastern Brazil. We analysed 121 parasitised specimens representing 15 species, recording body size metrics (SVL and mass) and calculating parasitological indices. Significant phylogenetic signal was detected for host body size (SVL and mass) and mean intensity of infection, whereas no phylogenetic signal was found for mean parasite richness. Contrary to the island theory predictions, PGLS models revealed a significant negative relationship between mean SVL/mass and mean intensity of infection. Furthermore, no significant relationship was found between host body size (SVL or mass) and mean parasite richness, regardless of the evolutionary model used. The pPCA identified a predominance of global structure (phylogenetic relatedness), explaining 42.15% of the variation, while local structures, reflecting niche differentiation, accounted for 18.61%. Our results demonstrate that lizard–parasite interactions are shaped by a complex synergy between conserved evolutionary templates and opportunistic ecological responses, highlighting the necessity of integrated phylogenetic approaches in parasitological studies.

The inclusion of parasites in inventories has provided relevant information on the knowledge of biodiversity. Integrating accurate taxonomy and species identity of both hosts and parasites can result in valuable insights into the association’s evolutionary relationships, geographic distribution, and dynamics. Besides the risk of diseases related with some parasites, herein we also highlighted the great diversity revealed in parasite communities associated with amphibians and reptiles, varying from unicellular to metazoan organisms occupying numerous tissues throughout the host’s body. To be aware of this diversity, the first step is to implement taxonomic studies performing appropriate methods for collecting and preserving specimens. Here, we aim to provide a useful hands-on guide to parasitological data collection from amphibians and reptiles. We write especially for those aiming to include parasitological data in their sampling, and for herpetologists and naturalists who already collaborate with parasitologists. We also provide some fundamental knowledge on the morphology and life cycle of the main parasites associated with herps, as well as protocols and tips for better collecting and preserving each type of parasite.

Pentastomida are lung parasites of a variety of hosts, mainly reptiles. Raillietiella is the genus with the largest number of species, whose taxonomic identification is still largely based on morphological data alone. In this classification, differences divide the genus into morphotypic groups. The Raillietiella parasites of insectivorous lizards, for example, are divided into “Group I” with species with hooks with sharp tips and “Group II” with posterior hooks with blunt tips. In the present work, we used molecular analysis to infer the morphological variation in hooks and size of specimens of Raillietiella mottae, parasites of several species of insectivorous lizards. Our results demonstrate that morphological differences comprise a phenotypic plasticity of a single species, whose variation is associated with host species, with females being larger and with hooks with blunt tips in nocturnal geckos and smaller ones with sharp tips in diurnal insectivorous lizards of different species, sizes, and habitats.

Pentastomids are hematophagous parasites whose adult forms live in the respiratory tract of their hosts. There are approximately 144 valid species of Pentastomida distributed in four orders (Christoffersen and Assis, 2013 CHRISTOFFERSEN, M.L. and ASSIS, J.E., 2013. A systematic monograph of the Recent Pentastomida, with a compilation of their hosts. Zoölogische Mededeelingen, vol. 87, no. 1, pp. 1-206. ). Some pentastomid species are host-generalist (Almeida et al., 2009 ALMEIDA, W.O., SANTANA, G.G., VIEIRA, W.L.S., WANDERLEY, I.C. and RIBEIRO, S.C., 2009. Rates of pulmonary infection by pentastomids in lizards species from a restinga habitat in northeastern Brazil. Brazilian Journal of Biology = Revista Brasileira de Biologia, vol. 69, no. 1, pp. 197-200. http://dx.doi.org/10.1590/S1519-69842009000100026. PMid:19347165. http://dx.doi.org/10.1590/S1519-69842009... ) while others are host-specific (Riley, 1986 RILEY, J., 1986. The biology of pentastomids. Advances in Parasitology, vol. 25, pp. 45-128. http://dx.doi.org/10.1016/S0065-308X(08)60342-5. PMid:3535437. http://dx.doi.org/10.1016/S0065-308X(08)... ). Parasites of the genus Raillietiella (order Raillietiellida) are commonly found in reptiles, but occur also in amphibians (Christoffersen and Assis, 2013 CHRISTOFFERSEN, M.L. and ASSIS, J.E., 2013. A systematic monograph of the Recent Pentastomida, with a compilation of their hosts. Zoölogische Mededeelingen, vol. 87, no. 1, pp. 1-206. ).

The parasitic fauna of reptiles is considered understudied compared to that of other vertebrates and is even less well known than the parasitic fauna of chelonians. Yet parasites are considered one of the main controllers of host populations because they can strongly impact population structure and species diversity. The objective of the present study was to identify the helminth fauna infecting freshwater turtles Phrynops geoffroanus and Mesoclemmys tuberculata, to evaluate the effects of host features (body mass and sex) and seasonality (dry and rainy seasons) on the abundance of parasites, and to compare infection rates in each host species between different biomes (Caatinga and Atlantic Forest) in an area of Northeastern Brazil. We found seven species of helminths that belong to Nematoda (Physaloptera sp., Serpinema amazonicus, Serpinema monospiculatus and Spiroxys figueiredoi), Cestoda (unidentified specimen), Digenea (Echinostomatidae) and Monogenea (Polystomoides brasiliensis). For both freshwater turtle species, we did not find a significant difference in the abundance of helminths related to the maximum carapace length, body mass or host sex; however, males had higher prevalence than females, while females presented greater abundance when infected. We observed significant differences in the infection levels between biomes and between seasons (dry and rainy), where the Atlantic Forest specimens showed higher infection rates compared to the Caatinga and the highest rates occurred in the dry season. The main parasitological parameters observed in P. geoffroanus and M. tuberculata showed that the studied biomes directly influenced the levels of parasitic infection. Variations in habitat characteristics can directly influence patterns of helminth diversity and abundance, and interactions between these characteristics can generate differences in parasitism rates of the same host species in different environments.

In this study, we investigated the infection by pulmonary parasites in the water snake Helicops angulatus. We found four nymphs of the pentastomide parasite Sebekia oxycephala, parasitizing two adult females H. angulatus collected in the municipality of Rio Tinto, Paraíba, Brazil. This occurrence is likely due to the nymphs of this parasite directly infecting aquatic intermediate hosts, such as fish. The result of this study represents the first record of pentastomid infecting H. angulatus.

Drymarchon coraisandCaiman crocodilusare reported here using different feeding behaviors for consuming poisonous toads of the genusRhinella(Bufonidae).Drymarchon coraiswas observed feeding on specimens ofRhinella diptychawithout avoiding contact with the parotoid macroglands, suggesting that this snake species is immune to toad toxins.Caiman crocodiluswas recorded avoiding contact with the parotoid macroglands of specimens ofRhinella marinaby consuming only the front and rear legs, suggesting that this caiman may be sensitive to toad toxins. Further experimental and field studies are needed to better understand the feeding behavior ofD. coraisandC. crocodilusand the effects ofRhinellatoxins on these predators.Abstract in Portuguese is available with online material.

The aim of this study was to identify and evaluate the chemical compositions and effects of the S. tuberosa leaf and root hydroalcoholic extracts (HELST and HERST) against different strains of Candida. Chemical analysis was performed by Ultra-Performance Liquid Chromatography Coupled to Quadrupole/Time of Flight System (UPLC-MS-ESI-QTOF). The Inhibitory Concentration of 50% of the growth (IC₅₀₎ as well as the intrinsic and combined action of the extracts with the antifungal fluconazole (FCZ) were determined by the microdilution method while the minimum fungicidal concentrations (MFCs) and the effect on fungal morphological transitions were analyzed by subculture and in humid chambers, respectively. From the preliminary phytochemical analysis, the phenols and flavonoids were the most abundant. The intrinsic IC₅₀ values for HELST ranged from 5716.3 to 7805.8 µg/mL and from 6175.4 to 51070.9 µg/mL for the HERST, whereas the combination of the extracts with fluconazole presented IC₅₀ values from 2.65 to 278.41 µg/mL. The MFC of the extracts, individually, for all the tested strains was ≥16384 µg/mL. When fluconazole was combined with each extract, the MFC against CA URM 5974 was reduced (HELST: 2048 and HERST: 4096 µg/mL). Synergism was observed against standard C. albicans (CA) and C. tropicalis (CT) strains and with the root extract against the CT isolate. The leaf extract inhibited the morphological transition of all strains while the root extract inhibited only CT strains.

We evaluated the activity period, thermal ecology, habitats, and preference for microhabitats of the skink Mabuya arajara in a humid forest environment on the slope of the Araripe Plateau, Brazil. A total of 283 lizards were observed. The lizards were found to be diurnally active (unimodal type pattern), with peak activity during the hottest hours of the day (1100 to 1200). About habitat use, the majority of individuals (73.8% N = 209) were recorded in the narrow transitional area, in the edges of the forest; while 26.4% of individuals were observed in open areas and no observations were made in dense forest. Seven different types of microhabitats were used, with fallen palm leaves (Arecaceae) being the preferred (47.7% N = 135). Considering all lizards, microhabitat niche breadth was 3.27. Males and females presented a high overlap (0.95) in microhabitat use. The average T_c recorded for M. arajara was 32.06 ± 2.72°C. Body size (SVL) did not influence body temperature (F = 0.51, P = > 0.05). Most of the animals were observed with their bodies completely exposed (67.84%, N = 192), 18.37% (N = 52) were semi-exposed and 13.79% (N = 39) were in shelters. Among animals with some degree of sunlight exposure, 57.59% (N = 163) were in shadows, 25.10% (N = 71) were under sunlight filtered by vegetation, and 17.31% (N = 49) were under direct sunlight.A review of the ecology of Mabuya spp. shows that several features appear to be conserved among members of the genus.