A biota aquática em um riacho tropical e suas relações com fatores ambientais

As unidades de conservação no Brasil carecem de informações que subsidiem os planos de manejo e as tomadas de decisões dos gestores para a conservação de sua biodiversidade. Este trabalho utilizou a biota aquática (zoobentos e peixes), além de parâmetros ambientais como pH, sólidos totais dissolvidos, condutividade elétrica, oxigênio dissolvido e temperatura para a caracterização ambiental de cada trecho estudado, objetivando avaliar a qualidade ambiental do único riacho do Parque Natural Municipal Corredores de Biodiversidade, localizado em Sorocaba, SP. Foram realizadas duas campanhas de amostragem, considerando as épocas seca e chuvosa, com rede “d”, com malha de 500μ para coleta dos macroinvertebrados e peneira, rede de espera e rede de arrasto para a captura dos peixes. Um total de 373 macroinvertebrados distribuídos em cinco ordens e seis famílias foram amostrados no riacho durante o período de estudo. A família mais abundante coletada foi a Chironomidae, com 138 organismos, sendo oportunistas e tolerantes à variação ambiental, comuns em ambientes alterados e com grandes quantidades de matéria orgânica depositada. Para os peixes, as ordens mais abundantes foram Characiformes e Cyprinodontiformes. Este estudo revelou que o riacho, apesar de estar situado numa unidade de conservação, apresenta perturbações associadas à erosão e sedimentação

Porcine circovirus type 3 : immunohistochemical detection in lesions of naturally affected piglets

This study aimed to evaluate the relationship between porcine circovirus type 3 (PCV3) viral load and histopathological findings in perinatal piglet tissues and to develop an immunohistochemical method for detecting the virus in lesions. The quantitative polymerase chain reaction (qPCR) cycle threshold (Ct) when amplifying PCV3 DNA and the area of perivascular inflammatory infiltrates in different organs [central nervous system (CNS), lung, heart, liver, spleen, and lymph nodes] were compared. To develop an immunohistochemistry technique, rabbit sera were produced against PCV3-capsid protein peptides selected using bioinformatic analyses. The assay was initially implemented using a tissue sample previously tested using qPCR and in situ hybridization to optimize the procedure and reagent dilutions. To evaluate immunohistochemistry performance, tissue samples from another 17 cases were analyzed using standardized parameters. The most common microscopic lesion was multisystemic periarteritis, with associated vasculitis, as the mesenteric vascular plexus is one of the most affected organs. Other tissues, such as the heart, lung, CNS, and skeletal muscle, were also affected. Comparison of the Ct values for different tissues showed no significant difference, except in lymphoid organs (spleen and lymph nodes), which had significantly higher viral loads than the CNS tissues. There was no correlation between Ct values and perivascular inflammatory infiltrates. PCV3 immunohistochemistry revealed granular immunolabeling, mainly in the cytoplasm of cells in the vascular mesenteric plexus, heart, lung, kidney, and spleen

Porcine circovirus type 3: immunohistochemical detection in lesions of naturally affected piglets

This study aimed to evaluate the relationship between porcine circovirus type 3 (PCV3) viral load and histopathological findings in perinatal piglet tissues and to develop an immunohistochemical method for detecting the virus in lesions. The quantitative polymerase chain reaction (qPCR) cycle threshold (Ct) when amplifying PCV3 DNA and the area of perivascular inflammatory infiltrates in different organs [central nervous system (CNS), lung, heart, liver, spleen, and lymph nodes] were compared. To develop an immunohistochemistry technique, rabbit sera were produced against PCV3-capsid protein peptides selected using bioinformatic analyses. The assay was initially implemented using a tissue sample previously tested using qPCR and in situ hybridization to optimize the procedure and reagent dilutions. To evaluate immunohistochemistry performance, tissue samples from another 17 cases were analyzed using standardized parameters. The most common microscopic lesion was multisystemic periarteritis, with associated vasculitis, as the mesenteric vascular plexus is one of the most affected organs. Other tissues, such as the heart, lung, CNS, and skeletal muscle, were also affected. Comparison of the Ct values for different tissues showed no significant difference, except in lymphoid organs (spleen and lymph nodes), which had significantly higher viral loads than the CNS tissues. There was no correlation between Ct values and perivascular inflammatory infiltrates. PCV3 immunohistochemistry revealed granular immunolabeling, mainly in the cytoplasm of cells in the vascular mesenteric plexus, heart, lung, kidney, and spleen

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Colonização de folhas por invertebrados aquáticos em um riacho tropical: há diferenças entre espécies nativas e Eucalyptus grandis (Hill ex Maiden) nas épocas chuvosa e seca?

The objective of the present study was to verify if there are differences in the colonization of invertebrates between the leaves of native and exotic species in the rainy and dry seasons. Senescent leaves were collected from a riparian forest along a stream and dried in a greenhouse at 60±5°C for 48 h. After drying, the plant material was added to litter bags randomly arranged in the stream. Two experimental treatments were used: (1) Eucalyptus grandis (non-native) and Lithraea molleoides (native species); and (2) Eucalyptus grandis (non-native) and Maytenus aquifolium (native species). The results showed that colonization mainly began on the 14th day and continued until the 28th day. Greater invertebrate abundances were found on the native leaves in the dry season and on the non-native leaves in the rainy season. Regarding taxonomic richness, the highest values were found starting on day 21 and there was a difference in the rainy season between native and non-native species, which did not occur in the dry season. According to a statistical analysis, in the rainy season the abundance of invertebrates was higher for the non-native species compared to the native species. On the other hand, there was a negative effect of the rainy season on richness. For both experiments, the main effect of the days did not influence the richness. There was an interaction effect between time of year and days of observation; in the rainy season, it is expected that there will be a significant linear increase in abundance over the days.O presente estudo objetivou verificar se há diferença na colonização de invertebrados aquáticos entre folhas de duas espécies nativas e uma não nativa considerando os períodos chuvoso e seco. Folhas senescentes foram coletadas da mata ripária do córrego e secas em uma estufa à temperatura de 60±5ºC por 48 h. Depois de seco, o material vegetal foi adicionado em “litter bags” disposto no riacho de maneira aleatória. Foram utilizados dois tratamentos experimentais: 1. Eucalyptus grandis (não nativa) e Lithraea molleoides (espécie nativa). 2. Eucalyptus grandis (não nativa) e Maytenus aquifolium (espécie nativa). Os resultados mostraram que o início da colonização foi principalmente no 14º dia, permanecendo até o 28º dia. As folhas nativas apresentaram maiores abundâncias de invertebrados na época seca, enquanto a não nativa na época chuvosa. Com relação à riqueza taxonômica, os maiores valores foram encontrados a partir do 21º dia, ocorrendo diferença no período chuvoso entre as espécies nativas e a não nativa, o que não ocorreu na época seca. De acordo com a Anova, foi observado que, na época chuvosa, a abundância de invertebrados foi maior na espécie não nativa em comparação com a nativa. Por outro lado, houve efeito negativo da época chuvosa sobre a riqueza. Para ambos os experimentos, o efeito principal dos dias não influenciou a riqueza. Ocorreu, contudo, um efeito de interação entre época do ano e dias de observação: na época chuvosa, espera-se que haja aumento linear significativo na abundância ao longo dos dias

Ocorrência de um molusco invasor (Melanoides tuberculata, Müller, 1774), em diferentes sistemas aquáticos da bacia hidrográfica do Rio Sorocaba, SP, Brasil

No Brasil e no estado de São Paulo existem poucos levantamentos sobre a presença do gastrópode Melanoides tuberculata (Müller, 1774). Os moluscos invasores representam uma importante ameaça às espécies nativas, em consequência da sua agressividade na competição pelo uso dos habitats e dos diferentes recursos. Melanoides tuberculata é originário da Ásia e África e a sua introdução no Brasil data da década de 60. Estudos recentes ressaltam a importância de realizar novas pesquisas sobre a distribuição espacial desta espécie e seu possível impacto à biodiversidade. O presente estudo documenta a ocorrência da espécie Melanoides tuberculata na bacia hidrográfica do rio Sorocaba, sua abundância e distribuição espacial em 5 sistemas aquáticos em diferentes estágios de conservação. As amostragens foram realizadas nos meses de junho de 2013 até agosto de 2014, onde foram registrados 522 indivíduos, dos quais 67% foram encontrados no Rio Verde, localizado na zona de amortecimento da Floresta Nacional de Ipanema. Os resultados mostraram que esta espécie pode estar amplamente distribuída na bacia principalmente em locais com substrato arenoso, mata ripária degradada e sujeito a lançamento de esgoto. Deve ser ressaltada ainda a correlação com valores de temperatura da água mais altos, o que pode estar ligado à ausência de sombreamento propiciado pela mata ripária. O controle na proliferação desta espécie, deve ser realizado pela melhoria da qualidade ambiental do ambiente aquáticos uma vez que a erradicação se torna inviável por remoção física