Effect of altitude and spatial heterogeneity on the host-parasite relationship in anurans from a remnant humid forest in the brazilian semiarid.

In the present study, we investigated the effect of habitat heterogeneity, elevation gradient, and phylogenetic distance of host species on the abundance and richness of anuran endoparasites, assuming that parasites follow the distribution of their hosts independently of environmental variation. We collected 192 anurans distributed in three altitude ranges: 100-200 m, 400-500 m, and 700-800 m. We performed discriminant principal component analysis to analyze the interrelationships between environmental heterogeneity and the distribution of parasite and host species in the formation of species groups in each altitude range. We estimated the niche width and parasite overlap, using host species as a variable, and assessed whether parasite abundance is more influenced by historical (distance host phylogeny) or ecological effects in each altitude category and overall. Finally, we use network analyses to understand how interactions between parasites and hosts are formed along the altitude gradient. We found 22 parasite species, and the overall prevalence of infection was 74%. In our study, we did not identify environmental (altitude gradients and heterogeneity) or phylogenetic effects acting on the parasite species diversity. Overall, our results suggest that the parasites are distributed following the dispersal of their hosts and are dispersed among most anuran species.

Endoparasites of Adelophryne maranguapensis Hoogmoed, Borges & Cascon, 1994 (Anura, Eleutherodactylidae), an endemic and threatened species from an altitude swamp in northeastern Brazil.

Adelophryne maranguapensis is an endangered anuran species endemic to the Maranguape residual mountain, Ceará State, northeaster Brazil, which is under strong anthropogenic pressure. There are still few studies on the natural history of this species that allow a better understanding of its biology and can provide the basis for conservation actions. Studies on endoparasitism are an important source for the comprehension of ecological relationships, as well as for providing information on host biology and its relevance to ecosystems. Thus, we present information about the endoparasites helminths, the relationship of parasite abundance with the size of individuals and the parasite difference between the sexes in A. maranguapensis, to elucidate some characteristics in the host-parasite relationship and the use of the area of this anuran. We analysed 107 specimens deposited in the Herpetological Collection of the Federal University of Ceará, sampled from 2010 to 2012. Total prevalence of 24.30% was recorded, and four parasitic taxa were identified, Aplectana sp., Physaloptera sp., Parapharyngodon sp. and an unidentified Ascarid. No relationship between the abundance of parasites and snout-vent length was found and the parasite difference between the sexes. Even though identification of the parasites at species level was not possible, A. maranguapensis follows a common pattern in parasitism of Neotropical species.

Molecular Screening of Plasmodium (Haemosporidia: Plasmodiidae) Parasites from Reptiles in Brazil.

Hemosporidians are a monophyletic group of protozoan parasites infecting all terrestrial vertebrate orders. Although Plasmodium is the most studied genus within the Haemosporidia, this research effort is heavily biased toward mammal and bird hosts. We screened 205 specimens of at least 18 reptile species from Brazil using a partial mitochondrial cytochrome b gene marker. Positive samples were sequenced and included in a phylogenetic assessment. Four positive PCR products matched others identified as Plasmodium using BLAST from 3 different host species, Ameiva ameiva, Tropidurus hispidus, and Hemidactylus mabouia. Recovery of similar haplotypes in the native T. hispidus and exotic H. mabouia (99.9%) indicate potential host-switching.

Anuran diversity indicates that Caatinga relictual Neotropical forests are more related to the Atlantic Forest than to the Amazon.

The relationships among the morphoclimatic domains of South America have been a major biogeographical issue of recent years. Palynological, geological and phytogeographical data suggest that the Amazon Forest and the Atlantic Forest were connected during part of the Tertiary and Quaternary periods. This study uses amphibians as model organisms to investigate whether relict northeastern forests are a transition between the Amazon Forest and the Atlantic Forest. We compiled matrices of species composition for four different phytogeographic formations and "Brejos de Altitude," and analyzed them using clustering methods and Cladistic Analysis of Distributions and Endemism. Our results indicate that the anurofauna of these northeastern forest relicts is most similar in composition to the areas of the Atlantic Forest included in this study, and most dissimilar to the Amazon Forest, which leads us to affirm that events of biotic exchange were more frequent within the Atlantic Forest areas.

Pulmonary mechanic and lung histology induced by Crotalus durissus cascavella snake venom.

This study have analyzed the pulmonary function in an experimental model of acute lung injury, induced by the Crotalus durissus cascavella venom (C. d. cascavella) (3.0 µg/kg - i.p), in pulmonary mechanic and histology at 1 h, 3 h, 6 h, 12 h and 24 h after inoculation. The C. d. cascavella venom led to an increase in Newtonian Resistance (RN), Tissue Resistance (G) and Tissue Elastance (H) in all groups when compared to the control, particularly at 12 h and 24 h. The Histeresivity (η) increased 6 h, 12 h and 24 h after inoculation. There was a decrease in Static Compliance (CST) at 6 h, 12 h and 24 h and inspiratory capacity (IC) at 3 h, 6 h, 12 h and 24 h. C. d. cascavella venom showed significant morphological changes such as atelectasis, emphysema, hemorrhage, polymorphonuclear inflammatory infiltrate, edema and congestion. After a challenge with methacholine (MCh), RN demonstrated significant changes at 6, 12 and 24 h. This venom caused mechanical and histopathological changes in the lung tissue; however, its mechanisms of action need further studies in order to better elucidate the morphofunctional lesions.

A new species of lizard Placosoma Tschudi, 1847 (Squamata: Gymnophthalmidae) from the relictual forest mountains of the State of Ceará, Brazil.

A new species of Placosoma Tschudi, 1847, until now restricted to the Atlantic Forest areas of southeastern Brazil is        described based on specimens obtained about 1700 km north to the current distribution of the genus. Placosoma limaverdorum spec. nov. is apparently endemic to three "brejos-de-altitude", relictual forest mountains surrounded by dry Caatingas, in the State of Ceará, northeastern Brazil. It differs from their congeners by the presence of an undivided transparent palpebral disk, a divided nasal scale with a central nostril, a deep tympanic recess, a distinctive and thin light vertebral stripe on the dorsal surface of the head, body and tail, femoral pores present only in males (21-26), preanal pores absent and additionally by having 21-24 rows of transverse ventral scales, 34-38 dorsals, dorsal, lateral and ventral scales smooth, dorsal scales quadrangular, longer than wide, except in the neck region, where they are wider than long.

Formal education, previous interaction and perception influence the attitudes of people toward the conservation of snakes in a large urban center of northeastern Brazil.

BACKGROUND: The attitudes and perceptions of people toward animals are influenced by sociodemographic factors, such as formal education and gender, and by personal experience. Understanding these interactions is critical for the establishment of conservation strategies for animals that have conflictual relationships with humans, such as snakes. Our study aims to explain how perceptions and the human fear of snakes vary and are influenced by formal education and gender. In addition, it aims to show how prior interaction with these animals influence these perceptions and the human fear toward snakes and how these perceptions and fear influence the importance of conservation of these animals. METHODS: We collected data from June 2010 to December 2013 using questionnaires given to 1142 visitors of a scientific serpentarium (Núcleo Regional de Ofiologia da Universidade Federal do Ceará) in the municipality of Fortaleza, northeastern Brazil. RESULTS AND DISCUSSION: Negative perceptions toward snakes were less frequent according to an increase in levels of schooling. Women had more negative perceptions and were more afraid of snakes than were men. Prior interaction with snakes decreased the occurrence of negative perceptions and reduced the level of human fear of these animals. People with negative perceptions classified the conservation of snakes as not important and were more afraid of these animals. Understanding the relationship between sociodemographic factors, prior experiences, perceptions, fear, and the importance given to conservation can help to better understand human attitudes toward snakes. CONCLUSIONS: Environmental education activities considering gender differences, involving preliminary interaction with snakes and focusing on priority targets identified in our study, such as people with low formal education, can increase the efficiency of measures for the conservation of these animals.

Bothrops erythromelas () venom induces apoptosis on renal tubular epithelial cells.

Bothrops erythromelas is responsible for a large number of snakebite incidents in Northeastern Brazil. Previously, we showed the effects of whole B. erythromelas venom in an isolated kidney model. To continue the study with B. erythromelas venom, the present work aims to study the effects of this venom on MDCK tubular epithelial cells and assess gene expression involved in kidney injury, aiming at elucidating the mechanisms responsible for renal toxicity. Cytotoxicity in MDCK cells showed an IC50 of 93 µg/mL and predominant apoptotic involvement demonstrated by flow cytometry assays and expression of caspase-3 and caspase-8. In conclusion, we suggest that Bothropoides erythromelas venom causes apoptosis with involvement of the caspases, probably through the extrinsic pathway.

Assessing the influence of geographic distance in parasite communities of an exotic lizard.

The decay of similarity between biological communities with increasing geographical distance is a well-established pattern in ecology, but there are more complex factors acting on host population connections that influence this association for parasite communities, such as parasites' colonization ability and degree of connectivity between host populations. Here we aim to determine the helminth communities associated with different populations of the host lizard Hemidactylus mabouia, testing if the similarity of parasite communities decreases as the distance between them increases. For this, we collected samples of lizard populations in seven sites from Northeastern coast of Brazil and identified parasite species of helminths and pentastomids in each host, calculated the Sørensen indices of presence/absence and abundance of each pair of communities and related them to the geographical distance. We did not find a relationship of decaying similarity with increasing distance between the parasite communities of the host populations. This can be explained by factors such as the characteristics of the contact between the host populations, and by modes of transmission of most parasite species. Furthermore, it may be related to the exotic nature of the host in Brazil so that parasite communities have not reached equilibrium.

Prevalence and diversity of Hepatozoon in native and exotic geckos from Brazil.

Hepatozoon is a genus of hemogregarines constituting the most widespread and common reptile hemoparasite. Although various molecular assessments of these parasites have been conducted in lizards from Africa and Europe, similar studies are needed for South American lizards. Through amplification and sequencing of fragments of the 18S rRNA gene, we assess the prevalence of Hepatozoon parasites in 230 geckos from South America, including the endemic species Hemidactylus agrius, Hemidactylus brasilianus, Lygodactylus klugei, Phyllopezus pollicaris, Phyllopezus periosus, and an exotic species, Hemidactylus mabouia . We found an overall low prevalence of Hepatozoon infection (7/230, 3%) with only 3 of the 6 host species infected with Hepatozoon ( Hemidactylus mabouia , P. pollicaris, and P. periosus). Within the 7 infected host samples, 5 genetically distinct lineages of Hepatozoon parasites were identified, only 1 of which was similar to previously published haplotypes. Thus, although prevalence is low, genetically based diversity of Hepatozoon in geckos from South America is very high. Three of these lineages appear basal to 1 of the major clades of Hepatozoon, suggesting that this clade might have originated in South America, and thereby indicating a potential phylogeographic pattern that had not been previously identified. Future studies should assess the distribution and competence of invertebrate hosts in the regions analyzed, and Hepatozoon diversity in other less well-known regions of the world.