Mixture of pesticides based on dimethylamine and imidacloprid affects locomotion of adult zebrafish.

Numerous chemical compounds are found in aquatic environments; among them are pesticides. Pesticides are widely used worldwide, and this use has progressively increased in recent decades, resulting in the accumulation of potentially toxic compounds in surface waters. Dimethylamine-based herbicides (DBH) and imidacloprid-based insecticides (IBI) have low soil absorption and high water solubility, facilitating the arrival of these compounds in aquatic environments. In this study, our objective was to analyze whether two pesticides, DBH and IBI at environmentally relevant concentrations of 320 µg/L for each compound, and their mixtures impact the behavioral and endocrine parameters of adult zebrafish, verifying the effect of pesticides on exploratory behavior and social and analyzing hormonal parameters related to stress. Acute exposure to the mixture of pesticides reduced fish locomotion. Pesticides alone and in combination did not affect cortisol levels in exposed animals. Pesticides, when tested together, can cause different effects on non-target organisms, and the evaluation of mixtures of these compounds is extremely important.

Bioaccumulation of pesticides and genotoxicity in anurans from southern Brazil.

The expansion of agricultural activities causes habitat loss and fragmentation and the pollution of natural ecosystems through the intense use of pesticides, which may affect the populations of amphibian anurans that inhabit agricultural areas. The present study evaluated the in situ bioaccumulation of pesticides in a population of Leptodactylus luctator that occupies farmland in southern Brazil. We also compared the genotoxicity of L. luctator populations from farmland and forested areas in the same region. We analyzed the micronuclei and nuclear abnormalities of 34 adult anurans, 19 from farmland, and 15 from the forested area. We also assessed the presence of 32 pesticides in liver samples obtained from 18 farmland-dwelling anurans, using chromatographic analysis. We recorded significantly higher rates of nuclear abnormalities in the individuals from the farmland, in comparison with the forest. We detected nine pesticides in the liver samples, of which, deltamethrin was the most common and carbosulfan was recorded at the highest concentrations. The bioaccumulation of pesticides and the higher levels of genotoxic damage found in the anurans from agricultural areas, as observed in the present study, represent a major potential problem for the conservation of these vertebrates, including the decline of their populations and the extinction of species.

Anurans of a remnant of Mixed Rainforest in southern Brazil / Anuros de um remanescente de Floresta Ombrófila Mista no sul do Brasil

Abstract: The Brazilian Atlantic Forest is one of the world's most biodiverse biomes, with large numbers of endemic and threatened species. However, this biome has suffered extensive deforestation and habitat fragmentation, with a drastic reduction of its original vegetation cover. The compilation of data on the occurrence patterns of anurans and their natural history is important for the development of effective conservation strategies. Here, we present the results of a survey of the anuran fauna of Parque Estadual do Papagaio Charão (PEPC) in Rio Grande do Sul state, southern Brazil, providing information on species endemism, conservation status, and reproductive modes. We collected data on the local anurans between March 2018 and February 2019 using active searches and pitfall traps. We recorded 26 anuran species distributed in seven families, with eight different reproductive modes. The largest number of species (20) was found at the forest edge, followed by the interior of the forest and open area, each with 16 species. The most abundant species were Leptodactylus plaumanni (41.7% of records), Physalaemus cuvieri (27.1%), and P. carrizorum (16.5%). Greater species richness and abundance were recorded during the rainier months, while temperature influenced only the abundance of the anurans. Rhinella henseli, Rhinella icterica, Vitreorana uranoscopa, Aplastodiscus perviridis, Boana curupi, Boana leptolineata and Proceratophrys brauni are all endemic to the Atlantic Forest. Melanophryniscus devincenzii is classified as Endangered by the IUCN, and Proceratophrys bigibbosa as Near Threatened. Boana curupi is considered to be Endangered in Rio Grande do Sul state, and Vulnerable in Brazil, while V. uranoscopa is Near Threatened in Rio Grande do Sul. Our findings emphasize the importance of protected areas, such as the PEPC, for the maintenance of anuran populations and communities in the Mixed Rainforest formations of southern Brazil.

Resumo: A Mata Atlântica abriga a maior biodiversidade do planeta, com elevados números de endemismos e espécies ameaçadas de extinção. Entretanto, esse bioma tem sofrido extensa perda e fragmentação do habitat, com redução drástica da sua cobertura vegetacional original. Suprir lacunas sobre a história natural e os padrões de ocorrências de anuros auxiliam no desenvolvimento de estratégias de conservação para esse grupo. Neste estudo apresentamos a anurofauna do Parque Estadual do Papagaio Charão (PEPC), no estado do Rio Grande do Sul, sul do Brasil, com informações sobre endemismos, status de conservação e modos reprodutivos das espécies. Nossas amostragens em campo ocorreram entre março de 2018 e fevereiro de 2019 e utilizamos procura ativa e pitfalls traps para a coleta dos anuros. Registramos 26 espécies de anuros distribuídas em sete famílias e oito modos reprodutivos. Um número maior de espécies foi encontrado na borda (20 espécies), seguida da floresta e área aberta (16 espécies cada). As espécies mais abundantes foram Leptodactylus plaumanni (41,7%), Physalaemus cuvieri (27,1%) e P. carrizorum (16,5%). Maior riqueza e abundância foram registradas no período com maior pluviosidade e a temperatura influenciou somente a abundância dos anuros. Rhinella henseli, R. icterica, Vitreorana uranoscopa, Aplastodiscus perviridis, Boana curupi, B. leptolineata e Proceratophrys brauni são endêmicas da Mata Atlântica. Melanophryniscus devincenzii está classificada como "Em perigo" e Proceratophrys bigibbosa como "Quase ameaçada" pela IUCN. Boana curupi é considerada "Em perigo" no estado do Rio Grande do Sul e "Vulnerável" no Brasil. Vitreorana uranoscopa consta como "Quase ameaçada" no Rio Grande do Sul. Nossos resultados mostram a importância de áreas protegidas, como o PEPC, para a manutenção das populações e comunidades de anuros da Floresta Ombrófila Mista.

Discovery of Wild Amphibians Infected with Ranavirus in Brazil.

Ranavirus is a double-stranded DNA virus associated with amphibian, fish and reptile die-offs worldwide. International trade of live animals farmed for human consumption, such as the American bullfrog (Lithobates catesbeianus), plays a key role in spreading the pathogen. In Brazil, ranavirus has only been reported in captive bullfrog farms. We found infected tadpoles of both native species and the American bullfrog in the wild, and a case of mass mortality of amphibians and fish potentially associated with ranavirus. Dead animals presented skin ulcerations, hemorrhages, and edemas. We also found an overall prevalence of 37% of the amphibian chytrid in the area, and two bullfrog tadpoles were co-infected with both pathogens. We suggest that the interaction between the two pathogens should be investigated to improve global conservation of ectothermic vertebrates.

Medium-sized mammals in peri-urban environments in southern Brazil / Mamíferos de médio porte em ambientes periurbanos no sul do Brasil

Anthropic effects on natural environments caused by urban expansion or agriculture havebeen identified as one of the causes for the decline in species richness. In southern Brazil, the urbanizationprocess affects the local fauna and reduces the diversity of mammalian species. This study was conductedfrom 2012 to 2015 with the objective of gathering information on mammalian species in a peri-urban area.Data was collected four consecutive days each month for 42 months using sand plots and visual searches.Occasional encounters and camera traps complemented were used to complement the data. We recorded15 mammal species belonging to 10 families. The species with the highest abundance, taking into accountall the applied methods, were Didelphis albiventris, Mazama gouazoubira and Cerdocyon thous. Four specieswere listed as endangered (Puma yagouaroundi, Leopardus guttulus, Nasua nasua, and Dasyprocta azarae).

A antropização de ambientes naturais, pela expansão urbana ou pela agricultura, tem sidoapontada como uma das causas da redução da riqueza de espécies. No sul do Brasil, esses processosafetaram a diversidade, extinguindo diversas espécies da mastofauna. Este estudo foi conduzido de 2012 a2015, com o objetivo de conhecer as espécies de mamíferos presentes em uma área periurbana. A coleta dedados foi realizada durante quatro dias por mês durante 42 meses, utilizando plots de areia e procura visual.Encontros ocasionais e armadilhas fotográficas complementaram os dados. Foram registradas 15 espécies demamíferos, distribuídas em 10 famílias. As espécies com a maior frequência, utilizando todos os métodos,foram Didelphis albiventris, Mazama gouazoubira e Cerdocyon thous. Quatro espécies estão listadas comoameaçadas regionalmente (Puma yagouaroundi, Leopardus guttulus, Nasua nasua e Dasyprocta azarae).

Herpetofauna do Parque Natural Municipal de Sertao, Rio Grande do Sul, Brasil

The northern part of the state of Rio Grande do Sul was extensively deforested in recent decades, and only isolated fragments of the original vegetation remain. The Parque Natural Municipal de Sertão comprises a remnant of Atlantic Rain Forest, one of the largest fragments in northern Rio Grande do Sul. This study examined the diversity of the herpetofauna, focusing on environmental distribution, seasonality and species richness. We used complementary methods of sampling such as pitfall traps, active search and occasional encounters. We recorded 23 species of frogs, nine snakes and one lizard. With respect to the relationship between amphibians and reptiles and the structural and abiotic factors of the environment, the edge of the fragment showed higher richness and increased dominance of amphibians and reptiles than the interior. The highest amphibian abundances were found when the minimum temperatures were higher and maximum temperatures were lower. The abundance of snakes was correlated with humidity, and species richness was influenced by humidity and monthly average temperature. Our results reinforce the importance of the conservation of forested areas to the maintenance of the species.

O norte do Rio Grande do Sul foi extensivamente desflorestado durante as últimas décadas e restaram somente fragmentos isolados das áreas originais. O Parque Natural Municipal de Sertão compreende um remanescente de Mata Atlântica, um dos maiores fragmentos do norte do Rio Grande do Sul. O objetivo deste estudo foi conhecer a diversidade da herpetofauna, enfocando aspectos da distribuição no ambiente, sazonalidade e riqueza de espécies. Utilizamos métodos complementares como armadilhas de interceptação e queda, procura ativa e encontros ocasionais. Registramos 23 espécies de anfíbios anuros, nove de serpentes e uma de lagarto. Encontramos relação entre os anfíbios e répteis e os fatores estruturais e abióticos do ambiente, onde a borda do fragmento apresentou maior riqueza e maior dominância de anfíbios e répteis que o interior do fragmento. As maiores abundâncias de anfíbios foram encontradas quando as temperaturas mínimas eram maiores e temperaturas máximas menores. A abundância de serpentes foi correlacionada com a umidade e a riqueza foi influenciada pela umidade e temperatura média mensal. Nossos resultados reforçam a importância da conservação de áreas florestadas para a manutenção das espécies.

O comportamento alimentar de Oxyrhopus rhombifer (Colubridae: Xenodontinae) em cativeiro / Feeding behavior of Oxyrhopus rombifer (Colubridae: Xenodontinae) in captivity

Aspectos do comportamento alimentar de Oxyrhopus rhombifer foram estudados no cativeiro, de junho de 1999 a maio de 2000. As serpentes, mantidas em terrários com uma temperatura media de 22°C, recebiam semanalmente, de manhã, a tarde e a noite, camundongos (Mus domesticus) de 8 a 22 g de peso, sendo observados os comportamentos de detecção, localização, perseguição, bote, constrição e ingestão. Os botes ocorreram na região posterior do corpo, em 62,8

dos casos, as constrições, em 55,4

dos casos, se deram com as espiras do corpo voltadas para o lado direito e em todos os casos, as serpentes apresentavam-se com o dorso virado para a região anterior do corpo. Em 97,5

The feeding behavior of snakes Oxyrhopus rhombifer was studied in captivity, from June 1999 to May 2000. Individuals were kept in terrariums under an average temperature of 22°C, and were given 8 to 22g mice Mus domesticus weekly, in the morning, in the afternoon and at night. Detection, localization, searching, attack, constriction and ingestion were observed. Attacks occurred in the posterior part of the body in 62.8

of the cases, constrictions occurred when the body turned rightwise in 55.4

of the cases and, in all cases, snakes presented themselves with their backs turned to the inner side of their bodies. In 97.5

dos casos, a ingestão iniciou-se pela cabeça da presa(AU)

of the cases the ingestion began with the head of the prey(AU)

Acidentes ofídicos na regiäo de Passo Fundo (RS) / Snakebites in the city of Passo Fundo, RS

Analisou-se 446 acidentes ofídicos, no período de 1990 a 1994, na abrangência da 6a. Delegacia de Saúde do Rio Grande do Sul, com o objetivo de avaliar o gênero da serpente que causou o acidente, idade e sexo do acidentado, hora do acidente, regiöes do corpo afetadas e sazonalidade. Avaliando-se os casos, pode-se constatar que o maior número de acidentes ocorreu com pessoas na faixa etária entre 16 e 30 anos; houve maior incidência no sexo masculino e pé, mäo, perna foram as regiöes do corpo mais afetadas. Os acidentes ocorreram no período de temperaturas mais altas do ano, com maior frequência no período da tarde. O gênero que causou o maior número de acidentes foi o Bothrops e a maior parte dos casos (43,8 por cento) foi classificada como leve quanto à gravidade