CECAV
URI permanente desta comunidadehttps://bdc.icmbio.gov.br/handle/cecav/1
Centro Nacional de Pesquisa e Conservação de Cavernas
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Resultados da Pesquisa
Item PAPEL DOS PEQUENOS MAMÍFEROS NÃO-VOADORES NA DISPERSÃO DE SEMENTES EM CANGA(2024-08-23) GODOI, MARIA FERNANDA REGIOLLI; Silveira, Fernando Augusto de Oliveira e; Paglia, Adriano PereiraA dispersão de sementes mediada por animais desempenha um papel crucial na promoção da regeneração natural em áreas degradadas, permitindo a chegada de sementes ao solo, estabelecendo bancos de sementes, conectando fragmentos e facilitando a recolonização de espécies nativas a um custo e tempo de manutenção menores. A dispersão de sementes por pequenos mamíferos não-voadores (PMNV) é realizada principalmente por marsupiais e roedores. Entretanto, em ambientes de topo de montanha, como os campos rupestres ferruginosos (canga), a endozoocoria por mamíferos é pouco conhecida. O estudo teve como objetivo investigar componentes da efetividade de dispersão de sementes (EDS) por PMNV e seu papel na regeneração de ecossistemas de canga degradados pelo impacto da mineração. Realizamos levantamentos de mamíferos em área de canga degradada (ACD) e preservada (ACP) no Parque Nacional Serra do Gandarela, Minas Gerais, Brasil, coletamos suas fezes, conduzimos experimentos de germinação e instalamos estações de remoção de diásporos para avaliar como a exclusão de vertebrados afeta a remoção de sementes. Registramos 13 espécies de mamíferos silvestres (ACD = 10, ACP = 10), sendo sete espécies de médio e grande porte (ACD = 4, ACP = 7), seis de PMNV (ACD = 6, ACP = 3), e três espécies domésticas invasoras de ambiente natural. Das 61 amostras fecais coletadas para PMNV, apenas três continham sementes de uma única espécie vegetal (Miconia oligochaeta). O índice de germinabilidade para a semente passada pelo trato digestório de Calomys tener foi de 0%, enquanto para Monodelphis domestica foi de 3,6% e para o tratamento controle 11,2%. Não houve diferença estatística significativa entre o tempo para a primeira germinação e o tempo médio de germinação para as sementes passadas pelo trato digestório de M. domestica e controle. Para o experimento de remoção de diásporos, não houve diferença entre o tratamento de acesso a vertebrados e de exclusão de vertebrados nos diferentes ambientes (degradado e preservado) ou estação (chuvosa e seca). Embora os PMNV desempenhem diversas funções no ecossistema, eles não foram dispersores eficientes de sementes nos ecossistemas de canga quanto ao aspecto qualitativo do EDS. No entanto, é necessário ampliar as amostragens, incluindo réplicas de áreas degradadas e preservadas, para melhorar os esforços de conservação e restauração.Item A New Genus of Prodidominae Cave Spider from a Paleoburrow and Ferruginous Caves in Brazil (Araneae: Prodidomidae)(2024-08-05) Cizauskas, Igor; Zampaulo, Robson de A.; Brescovit, Antonio D.A new monotypic genus of Prodidominae, Paleotoca gen. n., is proposed to include one cave species collected in a paleoburrow and ferruginous caves from Quadrilátero Ferrífero, Minas Gerais, Brazil: Paleotoca diminas sp. n. (♂♀). The new genus is closely related to other Neotropical Prodidominae by sharing the classic claw tuft clasper. Paleotoca gen. n. is diagnosed by the absence of a dorsal abdominal scutum, a ventral parallel rows of strong spines on the tibia and metatarsus I–II, a lack of a conductor, a discrete median apophysis on the bulb and a bifid retrolateral tibial apophysis in the male palp, a posterior extension that is beak-shaped, and folds of a copulatory duct ventrally visible in the female epigyne. Like other Prodidominae species from caves, P. diminas sp. n. is a troglobitic spider with morphological characteristics that indicate specialization to live in subterranean environments, including reduction in cuticular pigments, eye loss, heavy spination and trichobothria.Item Microhabitat selection and niche overlap: Drivers of spider coexistence in a tropical limestone cave(2024-10-10) Laís da Glória Teixeira Silveira; Thais Giovannini Pellegrini; Rodrigo Lopes Ferreira; Marconi Souza SilvaStable temperature, humidity, and oligotrophy may be essential in microhabitat selection, shaping niche overlap and species coexistence within cave ecosystems. To explore this hypothesis, we assessed the distribution and microhabitat preferences of four non-obligate cave-dwelling spiders: Loxosceles anomala, Scytodes itapevi, Philoponella vittata, and the exotic Oecobius navus. Using 1-m2 quadrats, we surveyed spider distribution and abundance in a limestone cave, considering environmental conditions and prey availability during wet and dry periods. Significant differences were observed between moist and dry periods regarding light intensity, wind speed, air temperature and moisture, potential prey, and the abundance of L. anomala. The exotic spider O. navus was more specialist, preferred brighter habitats, and showed lower niche overlap. Conversely, the three native species displayed greater niche overlap and preferred darker and more humid environments. Spatial disparities, rather than temporal variation, in species distribution underscored the influence of cave habitat conditions on species segregation. Furthermore, our findings highlighted the limited ability of the non-native O. navus to occupy more illuminated cave areas, thereby potentially safeguarding these habitats against biological invasion by this species.Item Marcadores moleculares utilizados em estudos na quiropterofauna (mammalia: chiropetra) brasileira(2023) Clarentino, Josenira dos Santos de Sousa; Macedo, Raimundo Gierdson AbreuAs técnicas de marcadores moleculares ganharam bastante visibilidade nos últimos anos, auxiliando diversos pesquisadores taxonomistas em uma classificação mais coerente dos seres vivos, considerando-se o grau de parentesco evolutivo. A aplicação de marcadores moleculares na pesquisa de Chiroptera, que compreende os morcegos, revela-se uma ferramenta valiosa para estudos taxonômicos, genéticos e ecológicos. A diversidade genética entre as espécies de morcegos pode ser elucidada por meio da análise de marcadores moleculares como sequências de DNA mitocondrial e nuclear, permitindo uma compreensão mais profunda das relações filogenéticas e padrões evolutivos dentro deste grupo. O principal objetivo desta pesquisa consiste em comparar os principais tipos de marcadores moleculares utilizados em estudos na quiropterofauna Brasileira. Os objetivos específicos se concentram em descrever a evolução do processo histórico dos marcadores moleculares. Identificar os principais tipos de marcadores moleculares utilizados em estudos na Quiropterofauna e caracterizar os marcadores moleculares. Para alcançar os objetivos propostos o presente estudo caracteriza-se como exploratório, de natureza qualitativo, delineado por pesquisas bibliográficas, fundado sobre pesquisas já publicadas, tendo como filtro palavras chaves: Estudos moleculares; Chiroptera molecular; Marcadores Chiroptera; Identificação molecular morcegos; morcegos moleculares Brasil; genética morcegos; molecular bats. Ainda, foram utilizados caracteres de truncamento para melhor resultado nas pesquisas, tais como: asteriscos (*); hífen (-) e aspas (“). A pesquisa consiste em artigos, teses dissertações entre os anos de 2012 a 2022, sendo limitado a pesquisas realizadas no Brasil. Apesar da vasta diversidade de morcegos no Brasil, os dados sobre esses mamíferos carecem de melhor visibilidade no meio cientifico. Com o surgimento das técnicas de marcadores moleculares em conjuntos com outras áreas de estudo, surge uma ferramenta capaz de revelar informações genéticas cruciais para a compreensão da variabilidade populacional e evolutiva, que vão muito além da taxidermia correta em termos de parentesco evolutivo.Item Iron Islands: The importance of iron caves in the eastern Amazon for bat conservation(2024-06-03) Torres, Dayana Ferreira; Bichuette, Maria ElinaThe Carajás region is home to the largest number of iron caves in Brazil, but studies that integrate elements of biological diversity and landscape characteristics are scarce. We present the first study based on the bat cave vulnerability index (BCVI), which uses bats as a key species for prioritizing caves in South America, whose objective was to assess the biotic potential and vulnerability of caves in the Carajás region, determining priority sites and the most effective conservation actions. The study took place from August 2021 to March 2023, where an inventory of the chiropterofauna of 12 caves was carried out. We recorded 16 bat species, two of which are vulnerable to extinction – Furipterus horrens (Cuvier, 1828) and Natalus macrourus (Gervais, 1856) – and two endemics to the Amazon region – Hsunycteris aff. thomasi (Allen, 1904) and Phyllostomus latifolius (Thomas, 1901); as well as one species with insufficient data to delimit its endemicity or threat status (Lonchophyllinae sp.). Mining is the main anthropogenic activity in the region, but tourism is also present and acts as a potential source of disturbance to the caves. The BCVI revealed three high priority caves for conservation and four with medium priority, indicating that these habitats are vulnerable to species loss and population decline due to exposure to anthropogenic activities and habitat destruction, thus requiring more effective conservation strategies. Considering the uniqueness of the subterranean habitats, we recommend re-evaluating the proposals for expanding mining activities, implementing controlled tourist visitation plans and conducting ecological studies and long-term monitoring.Item FOSSIL MAMMALS FROM LAJEDO DE SOLEDADE, QUATERNARY OF RIO GRANDE DO NORTE, BRAZIL(2024) COSTA, JOÃO PAULO DA; ADE, MARCUS VINÍCIUS BERAO; BERGQVIST, LÍLIAN PAGLARELLI; BARBOSA, FERNANDO HENRIQUE DE SOUZA; DANTAS, MÁRIO ANDRÉ TRINDADE; PORPINO, KLEBERSON DE OLIVEIRA; ARAÚJO-JÚNIOR, HERMÍNIO ISMAEL DEThe Lajedo de Soledade site, located in the municipality of Apodi, State of Rio Grande do Norte, is a vast karstic platform formed by carbonate rocks belonging to the Jandaíra Formation (Upper Cretaceous of the Potiguar Basin). The uplift of sedimentary rocks has exposed the formation to processes of erosion and leaching, leading to the creation of ravines and caves. These geological features, during the Quaternary Period, became repositories of sediments containing vertebrate remains. Recent collections conducted by the research team at the Paleontology Laboratory of the Universidade do Estado do Rio de Janeiro in the Araras Ravine and a new analysis of the fossil accumulation in the Leon Ravine have revealed new vertebrate taxa, especially mammals. The taxonomic study of these faunal accumulations identified at least thirteen different mammal taxa: Cerdocyon thous, Leopardus tigrinus, Puma concolor, Panthera onca, Mazama sp., Palaeolama major, Hippidion principale, Cuniculus sp., Euphractus sexcinctus, Glyptotherium sp., Tolypeutes cf. T. tricinctus, Dasypus novemcinctus, and Megalonychidae indet. The mammal taxa discovered in the layers of the Araras Ravine indicate the presence of at least two distinct environments in the Lajedo de Soledade Region: an open environment associated with denser areas resembling the Cerrado Bioma, and a drier environment akin to the current Caatinga Bioma. In the faunal assemblage of the Leon Ravine, four additional mammal taxa were identified: P. onca,Mazama sp.,Cuniculus sp., and Megalonychidae indet. The occurrence of Cuniculus sp. serves as a significant historical record for the genus within the state, further reinforcing the hypothesis that the paleoenvironment of the region comprised open areas intertwined with forested environments, potentially featuring small bodies of water. To gain a deeper understanding of the relationship between the ravines and any potential environmental transitions, geochronological, isotopic studies, and other data collections are crucial.Item Conservation gaps for Brazilian bats, limited protection across conservation units and the importance of the indigenous lands(2024-10-05) Rodrigues, F.B.; Alexandre, R.J.R.; Pena, S.A; et al.In Brazil, there is 13% of the world’s bat diversity, is the second most diverse group of mammals, playing a crucial role in providing ecosystem services that benefit humans. However, anthropogenic disturbances exacerbate processes of species extinction, shifts in geographic distributions, and phenological changes, despite efforts to safeguard biodiversity through the creation of Conservation Units and Indigenous Lands. Moreover, gaps in taxonomic knowledge and challenges related to species distribution hinder the effective implementation of conservation strategies in protected areas. This study assesses the contribution of Brazilian Conservation Units (both Full Protection and Sustainable Use) and Indigenous Lands to the conservation of bat species and their ecosystem services. It also presents maps illustrating species richness by trophic guilds and threat classification according to IUCN, including species listed as Data Deficient. The findings reveal low percentages of potential bat distribution areas within these protected regions, especially for insectivorous, nectarivorous, and frugivorous bats in the Cerrado biome, which are classified as Near Threatened. Additionally, the highest bat species richness was observed in the Amazon and Atlantic Forest biomes.Item We prefer nighttime, they prefer daytime: Biological rhythm variability in cave-dwelling whip spiders (Amblypygi: Charontidae) in the Neotropics(2024-10-13) Souza, P. E. de; Gonçalves, B. da Silva Brandão; Souza-Silva, M.; Ferreira, R. L.The lack of understanding regarding how endogenous and behavioral factors affect the biological rhythms of amblypygid arachnids in cave environments underscores a gap in chronobiologic knowledge for this group. This study investigates the influence of specialization on subterranean habitats and the presence of biological rhythms on the locomotor activity patterns of the troglobitic and troglophilic species of the genus Charinus. Specimens collected from carbonate caves in Brazil were subjected to experimental treatments of constant light (LL), constant darkness (DD), and light–dark cycles (LD). The results revealed variations in the distribution of main periods among species, without a uniform pattern. Although some specimens showed greater variability in activity patterns in the DD and LL treatments, no significant differences were observed between troglobites and troglophiles. The lack of a clear distinction in rhythms between the two groups suggests the dynamic nature of circadian rhythms in these populations, where individual variations in activity patterns indicate this behavioral diversity. Additionally, intraspecific competition for food resources, probably intensified by the oligotrophic conditions of the cave environments, may play an important role in shaping these patterns and differences in activity phases. The presence of infradian rhythms and weak circadian rhythms in some individuals underscores the importance of considering non-photic zeitgebers for a deeper understanding of these rhythms in cave organisms.Item Complete mitochondrial genomes of three vulnerable cave bat species and their phylogenetic relationships within the order Chiroptera(2024-08-22) Molina, Michele; Oliveira, Guilherme; Oliveira, Renato R. M.; Nunes, Gisele L.; Pires, Eder S.; Prous, Xavier; Ribeiro, Mariane; Vasconcelos, SantelmoThe IUCN Red List of Threatened Species contains 175 Brazilian bat species that are threatened by extinction in some degree. From this perspective, it is essential to expand the knowledge about the genetic diversity of vulnerable bats. Genomic sequencing can be useful to generate robust and informative genetic references, increasing resolution when analyzing relationships among populations, species, or higher taxonomic levels. In this study, we sequenced and characterized in detail the first complete mitochondrial genomes of Furipterus horrens, Lonchorhina aurita, and Natalus macrourus, and investigated their phylogenetic position based on amino acid sequences of protein-coding genes (PCGs). The mitogenomes of these species are 16,516, 16,697, and 16,668 bp in length, respectively, and each comprises 13 PCGs, 22 tRNA genes, two rRNA genes, and a putative control region (CR). In the three species, genes were arranged similarly to all other previously described bat mitogenomes, and nucleotide composition was also consistent with the reported range. The length and arrangement of rrnS and rrnL were also consistent with those of other bat species, showing a positive AT-skew and a negative GC-skew. Except for trnS1, for which we did not observe the DHU arm, all other tRNAs showed the cloverleaf secondary structure in the three species. In addition, the mitogenomes showed minor differences in start and stop codons, and in all PCGs, codons ending in adenine were more common compared to those ending in guanine. We found that PCGs of the three species use multiple codons to encode each amino acid, following the previously documented pattern. Furthermore, all PCGs are under purifying selection, with atp8 experiencing the most relaxed purifying selection. Considering the phylogenetic reconstruction, F. horrens was recovered as sister to Noctilio leporinus, L. aurita and Tonatia bidens shared a node within Phyllostomidae, and N. macrourus appeared as sister to Molossidae and Vespertilionidae.Item Obtaining High‐Resolution Magnetic Records From Speleothems Using Magnetic Microscopy(2024) Borlina, C. S.; Lima, E. A.; Feinberg, J. M; Jaqueto, P.; Lascu, I.; Trindade, R. I. F.; et al.Speleothems are mineral deposits capable of recording detrital and/or chemical remanent magnetization at annual timescales. They can offer high‐resolution paleomagnetic records of short‐term variations in Earth's magnetic field, crucial for understanding the evolution of the dynamo. Owing to limitations on the magnetic moment sensitivity of commercial cryogenic rock magnetometers (∼10− 11 Am2 ), paleomagnetic studies of speleothems have been limited to samples with volumes of several hundreds of mm3 , averaging tens to hundreds of years of magnetic variation. Nonetheless, smaller samples (∼1–10 mm3 ) can be measured using superconducting quantum interference device (SQUID) microscopy, with a sensitivity better than ∼10− 15 Am2 . To determine the application of SQUID microscopy for obtaining robust high‐resolution records from small‐volume speleothem samples, we analyzed three different stalagmites collected from Lapa dos Morcegos Cave (Portugal), Pau d'Alho Cave (Brazil), and Crevice Cave (United States). These stalagmites are representative of a range of magnetic properties and have been previously studied with conventional rock magnetometers. We show that by using SQUID microscopy we can achieve a five‐fold improvement in temporal resolution for samples with higher abundances of magnetic carriers (e.g., Pau d'Alho Cave and Lapa dos Morcegos Cave). In contrast, speleothems with low abundances of magnetic carriers (e.g., Crevice Cave) do not benefit from higher resolution analysis and are best analyzed using conventional rock magnetometers. Overall, by targeting speleothem samples with high concentrations of magnetic carriers we can increase the temporal resolution of magnetic records, setting the stage for resolving geomagnetic variations at short time scales.