Short-term impact of a wildfire on the homeostasis of Tropidurus oreadicus lizards.

Wildfires cause significant changes in natural habitats and can impact lizard populations. Through changes in the thermal environment, reduced prey availability, and increased exposure to parasite vectors, wildfires affect lizard physiology, immunity, and health. We sampled 56 Tropidurus oreadicus lizards from Cerrado savannas of Brazil living in two adjacent sites: one burned 14 days before the study, and the other unburned for 6 years. We logged the air temperatures of those sites throughout fieldwork. We assessed the short-term possible homeostatic imbalances caused by the fires via measuring body mass, circulating levels of corticosterone (CORT), leukocytes profile changes in heterophile-lymphocyte ratios (HLRs), innate immunity using the bacterial killing assay (BKA), and the diagnosis of hemoparasites using molecular techniques. The air temperature was significantly higher in the burned site. There was no difference in lizard body mass between the two sites, suggesting that prey availability was not affected by the wildfire. While parasite presence was seemingly not affected by fire, the timing of initial parasite infection for animals in the study was unknown, so we also evaluated parasitism as an independent variable relative to the other metrics. Our results showed that parasitic infections lead to reduced bactericidal capacity and body mass in lizards, suggesting clinical disease and depletion of innate immune resources. Moreover, we observed increased HLR with fire and parasitic infections and a strong negative correlation with BKA. These findings suggest that the increased environmental temperature following wildfires may lead to increased CORT and decreased BKA.

Herpetofauna of protected areas in the Caatinga VIII: An updated checklist for the Serra das Confusões region with new data from Serra Vermelha, Piauí, Brazil / Herpetofauna das áreas protegidas da Caatinga VIII: Um inventário atualizado para a região da Serra das Confusões com novos dados da Serra Vermelha, Piauí, Brazil

Abstract It is repeatedly stressed the need to characterize the extant biodiversity in tropical ecosystems. However, inventory studies are still progressing slowly in dry ecosystems, leading to the underestimation of their true biodiversity and hindering conservation efforts. In this study, we present primary and secondary data, along with an updated list of amphibians and reptiles from two localities in the São Francisco-Gurguéia region in Piauí. Additionally, we compare the species composition between nine areas within the Caatinga, which were sampled using standardized methods over the past ten years, to examine broader spatial patterns of community composition. To survey reptiles and amphibians, we employed similar methods and sampling efforts in two areas within the Serra das Confusões National Park (SCNP) region. Our surveys recorded a total of 73 species of amphibians and reptiles, of which 24 are new distribution records for the SCNP region. Consequently, our findings increase the known herpetofauna in the region to 94 species. Despite their proximity, the two sites in the SCNP region exhibited only 42% similarity in species composition, and they differed significantly from other areas within the Caatinga. Furthermore, even the closer Caatinga areas presented differences in species composition, highlighting the necessity to evaluate biodiversity across the landscape and contribute to understanding biogeographic patterns.

Resumo É repetidamente enfatizada a necessidade de caracterizar a biodiversidade vivente em ecossistemas tropicais. No entanto, os estudos de inventário ainda estão progredindo lentamente em ecossistemas secos, levando à subestimação de sua verdadeira biodiversidade e dificultando os esforços de conservação. Neste estudo, apresentamos dados primários e secundários, juntamente com uma lista atualizada de anfíbios e répteis de duas localidades na região de São Francisco-Gurguéia, do Piauí. Além disso, comparamos a composição de espécies entre nove áreas dentro da Caatinga, que foram amostradas usando métodos padronizados nos últimos dez anos, para examinar padrões espaciais mais amplos de composição da comunidade. Para estudar répteis e anfíbios, utilizamos métodos e esforços de amostragem semelhantes em duas áreas na região do Parque Nacional da Serra das Confusões (PNSC). Nossos levantamentos registraram um total de 73 espécies de anfíbios e répteis, das quais 24 são novos registros de distribuição para a região do PNSC. Consequentemente, nossos resultados aumentam a herpetofauna conhecida na região para 94 espécies. Apesar da proximidade, os dois locais na região do PNSC exibiram apenas 42% de similaridade na composição de espécies e diferiram significativamente de outras áreas dentro da Caatinga. Mesmo áreas mais próximas da Caatinga apresentaram diferenças na composição de espécies, destacando a necessidade de avaliar a biodiversidade em toda a paisagem e contribuir para a compreensão de padrões biogeográficos.

Minimum infection rate of Ehrlichia minasensis in Rhipicephalus microplus and Amblyomma sculptum ticks in Brazil.

A new genotype phylogenetically close to Ehrlichia canis named as Ehrlichia minasensis was identified infecting cattle and deer in Canada, as well as Rhipicephalus microplus ticks and cattle in Brazil. Although it was detected in R. microplus, little is known about the epidemiology of this ehrlichiosis, especially in other tick species. This study evaluated the minimum infection rate of E. minasensis in Amblyomma sculptum and R. microplus ticks from locations where naturally infected cattle were previously detected. Overall, 45 engorged R. microplus ticks after molting [43 pools of adults (13.4%), and 2 pools of nymphs (4%)], and 42 engorged females post-oviposition (30.6%) (p=0.008) were positive by PCR for Ehrlichia sp. using the dsb, 16S rRNA and TRP36 genes, making a total of 87 R. microplus samples positive for Ehrlichia spp. (17.1%, IC 95% 14.01-20.75%). The partial sequences generated in the present study were 99-100% similar to the dsb DNA sequence of E. minasensis genotypes UFMG-EV and UFMT-BV, respectively, 100% similar to the 16S rRNA sequence of the E. minasensis genotype BOV2010 from Canada, and 99% similar to the TRP36 sequence of the Ehrlichia sp. UFMT-BV. The results of this study confirm the occurrence of transstadial transmission of this agent in R. microplus ticks and highlight the importance of R. microplus in the epidemiology and transmission of ehrlichiosis in cattle. No A. sculptum ticks were positive by PCR for E. minasensis.