Wild Populations Of Reptiles Research Articles

Paranannizziopsis spp. infections in wild snakes and a qPCR assay for detection of the fungus.

The emergence of ophidiomycosis (or snake fungal disease) in snakes has prompted increased awareness of the potential effects of fungal infections on wild reptile populations. Yet, aside from Ophidiomyces ophidiicola, little is known about other mycoses affecting wild reptiles. The closely related genus Paranannizziopsis has been associated with dermatomycosis in snakes and tuataras in captive collections, and P. australasiensis was recently identified as the cause of skin infections in non-native wild panther chameleons (Furcifer pardalis) in Florida, USA. Here we describe five cases of Paranannizziopsis spp. associated with skin lesions in wild snakes in North America and one additional case from a captive snake from Connecticut, USA. In addition to demonstrating that wild Nearctic snakes can serve as a host for these fungi, we also provide evidence that the genus Paranannizziopsis is widespread in wild snakes, with cases being identified in Louisiana (USA), Minnesota (USA), Virginia (USA), and British Columbia (Canada). Phylogenetic analyses conducted on multiple loci of the fungal strains we isolated identified P. australasiensis in Louisiana and Virginia; the remaining strains from Minnesota and British Columbia did not cluster with any of the described species of Paranannizziopsis, although the strains from British Columbia appear to represent a single lineage. Finally, we designed a pan-Paranannizziopsis real-time PCR assay targeting the internal transcribed spacer region 2. This assay successfully detected DNA of all described species of Paranannizziopsis and the two potentially novel taxa isolated in this study and did not cross-react with closely related fungi or other fungi commonly found on the skin of snakes. The assay was 100% sensitive and specific when screening clinical (skin tissue or skin swab) samples, although full determination of the assay's performance will require additional follow up due to the small number of clinical samples (n = 14 from 11 snakes) available for testing in our study. Nonetheless, the PCR assay can provide an important tool in further investigating the prevalence, distribution, and host range of Paranannizziopsis spp. and facilitate more rapid diagnosis of Paranannizziopsis spp. infections that are otherwise difficult to differentiate from other dermatomycoses.

Salmonella enterica in Invasive Lizard from Fernando de Noronha Archipelago: Serotyping, Antimicrobial Resistance and Molecular Epidemiology.

Salmonella infection can pose serious health issues, especially to children, elders or immunosuppressed humans. Wild populations of reptiles can reach Salmonella prevalence of up to 100% and the direct or indirect transmission from reptiles to humans have been extensively reported. Fernando de Noronha (FN) is an inhabited oceanic archipelago in the northeast coast of Brazil, with an economy based on tourism. The tegu (Salvator merianae) is the largest lizard native to South America and was introduced to the archipelago in the early 20th century. This study determines the prevalence, serotypes, antimicrobial resistance, and molecular epidemiology of Salmonella enterica in the tegu population from FN archipelago. Results show that S. enterica is widely distributed in the FN tegu population, with 43.8% prevalence. The bacteria were isolated from 70.5% of the sampled sites and a total of 15 serotypes were detected in 98 S. enterica isolates. Strains were further classified into 31 genotypes. Recaptured animals presented distinct genotypes in each season, demonstrating a seasonal strain turnover. Most S. enterica isolates from FN tegus presented low antimicrobial resistance. This is possibly due to geographical isolation of the island population, hampering contact with strains from livestock from the continent, where antimicrobial resistance is common.

Statistical methodology for the evaluation of leukocyte data in wild reptile populations: A case study with the common wall lizard (Podarcis muralis).

The leukocyte profile has the potential to be a reliable method to measure health conditions and stress in wild animals, but limitations occur because current knowledge on reference intervals is largely incomplete, especially because data come from studies on captive animals involving few individuals from single populations. Here we propose a general framework for achieving reliable leukocyte reference intervals, encompassing a set of internal and external factors, potentially affecting the leukogram. To do so, we present a systematic survey of the hematology of the common wall lizard, Podarcis muralis, involving 794 lizards from 54 populations over the whole geographic range of the species in Italy. Reference intervals for white blood cell (WBC) and leukocyte differential count were obtained by using linear mixed models in a Bayesian framework. The application of the procedure clearly showed that both internal (sex and size) and external (latitude and season) factors are a source of variation of leukocyte profile. Furthermore, the leukogram of common wall lizard has a strong variability among populations, which accounts for more than 50% of the whole variation. Consequently, some common assumptions used in studies on captive individuals are no longer supported in wild populations, namely, i) any group of individuals is a representative sample, ii) any population is representative of all others, iii) geographic clines do not occur over the species range, and iv) seasonal variation has limited effects. We encourage researchers aimed at the definition of leukocyte reference intervals for wild populations of reptiles to involve a large number of populations over a wide geographic range in ad hoc statistical models to disentangle local and geographic effects on leukocyte profile variation.

Red Fire Ant (Solenopsis invicta) Effects on Broad-Snouted Caiman (Caiman latirostris) Nest Success

Abstract Flooding and predation are the two major causes for the decline in hatching rate and hatchling survival in crocodilian species. Recently, Solenopsis invicta (Red Fire Ant) has been recognized as a formidable invasive species, causing changes in wild populations of reptiles. Because of the elevated densities of Red Fire Ants present in Caiman latirostris (Broad-Snouted Caiman) nests during the breeding season, experiments in captivity and in the wild were performed to verify if the presence of S. invicta affects nest success or care of eggs and the hatching-assistance behavior of C. latirostris females. Hatchling survival from eggs incubated in a lab setting in the presence of Red Fire Ants decreased by approximately 10% compared to nests without ants. In a second experiment performed in the wild, the presence of Red Fire Ant resulted in a 43% reduction in nest success including direct (14.5%) and indirect (28.5%) effects. Our study confirmed that Red Fire Ants negatively affect C. latirostris nes...

New host records for Amblyomma rotundatum (Acari: Ixodidae) from Grussaí restinga, Rio de Janeiro, Brazil

Amblyomma rotundatum Koch is a parthenogenetic tick usually associated with reptiles and amphibians. However, relatively few studies on occurrences of ticks in wild reptile populations in Brazil have been produced. The aim of this study was to analyze the presence of ticks associated with reptile species in the Grussaí restinga, in the municipality of São João da Barra, state of Rio de Janeiro, Brazil. Between December 2010 and January 2011, 131 individuals belonging to nine species of reptiles of the order Squamata were sampled: the lizards Tropidurus torquatus (n = 51), Hemidactylus mabouia (n = 25), Mabuya agilis (n = 30), Mabuya macrorhyncha (n = 6), Cnemidophorus littoralis (n = 5) and Ameiva ameiva (n = 10); and the snakes Philodryas olfersii (n = 2), Oxyrhopus rhombifer (n = 1) and Micrurus corallinus (n = 1). The only tick species found to be associated with any of the reptiles sampled was A. rotundatum. One adult female was detected on one individual of the lizard A. ameiva, one nymph on one individual of the lizard T. torquatus and four nymphs on one individual of the snake P. olfersii. This study is the first record of parasitism of A. rotundatum involving the reptiles T. torquatus and P. olfersii as hosts. Our results suggest that in the Grussaí restinga habitat, A. rotundatum may use different species of reptiles to complete its life cycle.

Selected Infectious Diseases of Wild Reptiles and Amphibians

Infectious diseases have caused a decline in captive and wild populations of reptiles and amphibians. Contributing factors for the decline of wild populations, and their increased susceptibility to infectious diseases, include environmental pressures, such as loss or decline of habitat, exposure to pollutants, and translocation into new habitats. Reptiles and amphibians are often exposed to new pathogens after collection from the wild. Stress from handling, shipping, and substandard husbandry practices make these animals more susceptible to infection because of compromised immune function. Additionally, species from different geographic regions are often mixed after collection and thus exposed to novel pathogens. There is also evidence that pathogens may evolve to infect novel species other than their host species. Veterinary diagnostics and treatments aim at early detection of infectious diseases and development of effective treatment protocols, including effective quarantine practices and health screens of newly imported/collected animals. Diagnostic tools need to be developed to screen captive and wild populations for exposure to pathogens. Effective measures need to be implemented to protect the habitat of wild reptile and amphibian populations and also prevent introduction of pathogens into wild populations.

Vitellogenin induction by xenobiotic estrogens in the red-eared turtle and African clawed frog.

Many environmental pollutants have estrogenic activity in animals. Xenobiotic estrogens include many pesticides and industrial chemicals that biocumulate. The impact of these common pollutants on the reproductive success of wildlife may be considerable, particularly in threatened or endangered species. This research examined the use of plasma vitellogenin in males as a biomarker for estrogenic xenobiotics in reptiles and amphibians. Adult male turtles (Trachemys scripta) and frogs (Xenopus laevis) were given ip injections of estradiol-17 beta (E2), diethylstilbestrol (DES), or o,p'-DDT (1-chloro-2-[2,2,2-trichloro-1-(4-chlorophenyl)ethyl)benzene) daily for 7 days, and plasma was collected on day 14. The estrogenic activity of each compound was determined by measuring the induction of plasma vitellogenin. Vitellogenin was identified by precipitation, electrophoresis, Western blot, and enzyme-linked immunosorbant assay (ELISA). In both species, estradiol and DES treatments induced the most vitellogenin, whereas DDT treatments induced smaller amounts of vitellogenin in a dose-dependent fashion. These data indicate that induction of plasma vitellogenin in males may be a useful biomarker of xenobiotic estrogen activity in wild populations of reptiles and amphibians.