RCAAP Repository

RESUMO Testaram-se as hipóteses de que, assim como em reservatórios de grande áreas de superfície, volumes e vazão, em reservatórios pequenos também ocorrem a diluição gradual e contínua da riqueza, da diversidade e abundância de microcrustáceos (Cladocera e Copepoda) a jusante dos mesmos, sem a recomposição da riqueza a jusante pela falta de rios tributários, lagoas marginais e até pelo pequeno porte do riacho, sem condições para o desenvolvimento do potamoplâncton próprio do sistema. Foram estudados dois pequenos reservatórios e seus trechos a jusante, com coletas diárias a cada seis horas em oito pontos de amostragem, sendo dois lênticos e seis lóticos a jusante de cada. Foram encontradas 19 espécies (11 de Cladocera e oito de Copepoda), com destaque para o maior número de espécies litorâneas do que pelágicas, e a maior abundância de cladóceros litorâneos nos pontos a jusante dos reservatórios. Não houve diferença entre os horários, indicando que a escala espacial foi mais importante que a temporal. Houve maiores valores dos atributos ecológicos nos ambientes lênticos, porém houve aumentos significativos de riqueza e diversidade nos últimos pontos dos trechos de riacho, enquanto que a abundância diminuiu gradativamente a jusante. Não foram encontradas correlações significativas da abundância dos táxons com nenhuma variável limnológica (temperatura, pH, oxigênio dissolvido, turbidez, sólidos totais dissolvidos e transparência), indicando pouco ou nenhum efeito destas variáveis. A análise de cluster com distância euclidiana separou dois grandes grupos, o primeiro formado pelo trecho a jusante do primeiro reservatório e o segundo com os demais pontos. Além da presença dos táxons litorâneos vindos dos reservatórios, houve incremento de táxons litorâneos residentes nos riachos. Pode-se concluir que houve uma diluição da abundância das espécies a jusante dos riachos, mas a riqueza e a diversidade permaneceram estáveis devido à contribuição de táxons litorâneos.

ABSTRACT Stream insects use in different ways the stream habitats which affect patterns of species occurrence on stream. The nestedness is one of these patterns being an ecological mechanism that generates beta diversity. In this study, we verify the effects of temporal environmental variations on nestedness patterns of Chironomidae assemblages on subtropical streams. We collected chironomid larvae during winter and summer during three years (2010, 2011 and 2012) in Brazilian Subtropical low-order streams (Erechim, state of Rio Grande do Sul, Brazil). We measured environmental variables in each stream. To assess if assemblages will show nested patterns intra- and interannual we used a NODF metric. We observed nestedness only in one year, this pattern was due to variation of limnological factors, which are directly associated with climatic conditions (precipitation and water temperature) and agricultural management (e.g. dissolved oxygen and nutrients). Climatological events affect Chironomidae community through the time. The variations on precipitation values could be one of the mainly factors that influence nestedness for this community. Finally, studies on nesting on time scales should consider inter-annual comparisons, as climatic variations are more evident.

ABSTRACT Daily activity patterns are important elements of species behavior that reflect how they interact with their environment and with other related species. To investigate these patterns is crucial to understand how environmental or community changes may affect this behavior in each particular species. Within the Felidae family, research becomes fundamental to assess how small wild cats respond to local conditions and pressures, once there is a large gap in studies addressing such issues. Leopardus guttulus (Hensel, 1872) is an endangered species classified as Vulnerable (VU) at a regional and global level, being threatened mainly by the loss and fragmentation of its habitats. The aim of this study is to document the daily activity patterns of L. guttulus at the Lami Biological Reserve, and the influence of seasonality and temperature on those patterns. We also aimed to quantify how many individuals were using the Biological Reserve during the study period and evaluate their permanence in the area. We obtained 25 independent records for L. guttulus, which was the only cat species recorded at the site during the study period. In general, the species presented a cathemeral habit, being active throughout the 24 hours of the day, but with a more crepuscular/nocturnal activity in the spring and summer. The relationship between the species’ activity and temperature showed that more than 70% of the records were obtained in a narrow range of 10-17°C. We identified at least two individuals that remained at the site from four to six months of the year, with a higher detection frequency between August and November. Our results showed some interesting trends for the temporal activity of L. guttulus, suggesting flexibility related to seasonality, and the importance of the biological reserve to the preservation of this cat species in the southern limit of its distribution.

ABSTRACT Histological analysis of bleached samples of Siderastrea stellata Verrill, 1868, with white plague disease and with alteration in the color pattern, revealed drastic tissue and cellular disturbances, such as lysis of the external epithelium, hyperplasia of gastrodermis, apoptosis of epithelial cells and zooxanthellae, and degradation of mesenteric filaments and reproductive cells. Fungal hyphae, diatoms, and cyanobacteria were present in diseased samples and colonies with alteration in the color pattern. Furthermore, bleached and diseased samples showed significant reductions in the number of zooxanthellae per 100 µm2 of gastrodermis and significant reductions in the diameters and volumes of stage V oocytes. We found that bleaching events, diseases, and colonies with alteration in the color pattern promoted degradation of reproductive cells, resulting in the consequent interruption of the reproduction of the coral S. stellata, which is one of the most common Brazilian coral species. The implications of these indirect effects of bleaching, disease, and changes in coral color patterns in the population dynamics of Brazilian reefs are discussed.

RESUMO Esse estudo objetivou avaliar sazonalmente a histomorfometria do epidídimo de Dermanura cinerea (Gervais, 1856) em um fragmento de Mata Atlântica no nordeste do Brasil. Foram utilizados 18 espécimes machos adultos capturados por redes de neblina. As coletas ocorreram mensalmente ao longo de dezoito meses, durante duas noites consecutivas e os dados meteorológicos foram fornecidos pelo Instituto Nacional de Meteorologia. Depois de eutanasiados, os espécimes tiveram os epidídimos coletados e esses órgãos foram fixados e processados. As lâminas histológicas foram coradas por Hematoxilina - Eosina e analisadas em microscopia óptica. Os parâmetros morfométricos analisados foram as áreas do túbulo, do lúmen e do epitélio das regiões do segmento inicial, cabeça, corpo e cauda do epidídimo. Os dados histomorfométricos obtidos foram submetidos às análises no teste U de Mann-Whitney. Os resultados revelaram que D. cinerea apresentou espermatozoides em todas as regiões do epidídimo, exceto no segmento inicial. As maiores médias das áreas tubular, do lúmen e do epitélio nas quatro regiões, foram constatadas durante os meses secos. Portanto, D cinerea apresentou maior sensibilidade na região da cauda do epidídimo, ao longo dos meses com baixos índices pluviométricos. Isso indica que as condições ambientais apresentam considerável influência sobre a morfofisiologia epidídimária dessa espécie, sobretudo, em relação ao armazenamento de espermatozoides na cauda desse órgão, em área de Mata atlântica do nordeste brasileiro.

RESUMO Urbanização afeta a composição e funções ecossistêmicas das comunidades de morcegos em várias regiões do planeta. Entretanto, este ainda é um tema pouco explorado no Neotrópico. No Brasil, embora poucas cidades apresentem inventários de quirópteros, órgãos municipais de saúde pública (e.g., Centro de Controle de Zoonoses) realizam a vigilância passiva dos morcegos infectados pelo vírus da raiva. Estas instituições fazem a identificação dos espécimes oriundos principalmente de áreas urbanas e coletam dados biológicos importantes para o manejo ambiental, controle populacional, ecologia e conservação das espécies. O presente estudo analisou os dados de recebimento de morcegos, de 2001 a 2017, oriundos da cidade de Guarulhos, comparando as taxas de recebimento, frequência, riqueza e dominância das espécies com estudos prévios conduzidos em cidades brasileiras. Os dados da vigilância em saúde pública demonstraram uma alta riqueza de espécies (n = 29), representadas por três famílias mais comuns em áreas urbanas brasileiras (Phyllostomidae, Molossidae e Vespertilionidae). Molossus molossus (Pallas, 1766), Glossophaga soricina (Pallas, 1766) e Myotis nigricans (Schinz, 1821) representaram a maioria (70%) dos dados da quiropterofauna de Guarulhos. Esta dominância pode estar relacionada com a flexibilidade da dieta dessas espécies (insetívoras e nectarívoras não obrigatórias) e abrigos diurnos em edificações, recursos estes altamente disponíveis nas cidades brasileiras. Assim, para mitigar os efeitos da urbanização sobre a rica quiropterofauna regional, recomenda-se que o planejamento ambiental das cidades considere suas diretrizes urbanísticas e florísticas como uma ferramenta ao manejo integrado da fauna silvestre e saúde pública, além de implantar estratégias para aumentar o potencial de conservação da biodiversidade nestes ambientes.

ABSTRACT The minute litter bug genus Corixidea Reuter, 1891 currently comprises nine valid American species. Herein, we describe Corixidea quaresmai sp. nov. from one of the last remaining remnants of Atlantic Forest in northeast Brazil. The new species is characterized by the distal extension of the anophoric process parallel and close to the left lateral margin of the tergites, and the elongated process of tergum 8, with a pectinate distal half and a filiform tip. We provide diagnosis, images of habitus and male genitalia.

RESUMO O conhecimento das táticas reprodutivas é fundamental para a compreensão das estratégias do ciclo de vida dos peixes, bem como para nortear medidas de manejo e conservação. Com isso, o presente estudo teve como objetivo verificar os aspectos relacionados à reprodução de sete espécies do rio Sorocaba, maior afluente da margem esquerda do rio Tietê e muito importante para a manutenção das espécies de peixes no trecho médio desse rio. Foram realizadas coletas mensais durante o período de setembro de 2010 a setembro de 2012 em dois pontos situados no médio e baixo Sorocaba. As espécies estudadas foram: Astyanax lacustris (Lütken, 1875), Psalidodon cf. fasciatus (Cuvier 1819), Megaleporinus obtusidens (Valenciennes 1837), Parodon nasus Kner, 1859, Prochilodus lineatus (Valenciennes, 1837), Salminus hilarii Valenciennes, 1850 e Triportheus nematurus (Kner, 1858). Foi verificada correlação significativa entre a captura das espécies e a temperatura (Spearman r = 0,79, p = 0,0001) e pluviosidade (Spearman r = 0,60, p = 0,00014). Também foi verificada correlação significativa entre os estádios em maturação e maduro, temperatura e pluviosidade, mostrando a importância desses fatores na regulação do ciclo reprodutivo das espécies nos locais estudados. Evidencia-se um padrão de sazonalidade reprodutiva, que foi confirmado pelas medianas do Índice Gonadossomático ao longo dos meses. As espécies migradoras, P. lineatus e S. hilarii, tiveram seus picos de reprodução na época de cheia do rio. Nos meses de novembro a março foi registrada a maior atividade reprodutiva, resultante da interação entre os fatores bióticos e abióticos (temperatura e nível pluviométrico), uma vez que estes atuam na maturação das gônadas.

ABSTRACT Climatic conditions and microhabitat characteristics, such as the substrate and type of vegetation, influence the choice of male anurans for calling sites that optimize their reproductive success. We evaluated the structure and selection of vocalization microhabitat of 17 individuals of Phyllomedusa distincta Lutz, 1950 and 25 of Boana leptolineata (Braun & Braun, 1977), in a subtropical forest in southern Brazil. We measure the height of the perch, the distance between the perch and the edge of the body of water and the structure of the microhabitat of quadrants used by individuals. The same attributes were measured in the quadrants available (but not used) by the individuals. We classified the microhabitats by visual estimate, assigning percentages of coverage for each quadrant by herbaceous, shrub, tree and wetland vegetation. We observed that both species selected their microhabitat, since the characteristics of the quadrants occupied by the individuals were different from those available. Phyllomedusa distincta was more associated with heterogeneous microhabitats, while B. leptolineata occurred in environments with greater coverage of tree strata. Additionally, we observed that both species used shrubs more frequently as a perch site. The selection of these microhabitat characteristics must be associated with strategies to optimize the use of the reproductive habitat, based on the morphological and behavioral characteristics of the species. Finally, it is possible to infer that the differences observed in the microhabitat structure selected by the species can facilitate the coexistence of both in the context of the heterogeneity of the environment.

ABSTRACT The assemblage of helminths of Trachemys dorbigni was analyzed according two environments (rural and urban) and according to host’s gender. Thus, the helminths found were: Spiroxys contortus (Rudolphi, 1819), Falcaustra affinis (Leidy, 1856), Camallanus emydidius Mascarenhas & Müller, 2017, Dioctophyme renale (Goeze, 1782) (larvae), Eustrongylides sp. (larvae) (Nematoda), Telorchis corti (Stunkard, 1915), Telorchis achavali Mañé-Garzón & Holcman-Spector, 1973, Telorchis spp. (Digenea), Polystomoides rohdei Mañé-Garzón & Holcman-Spector,1968 and Neopolystoma sp. (Monogenoidea). Parasitological indices suggests that S. contortus, F. affinis, C. emydidius, T. corti and P. rohdei are species common in helminth assemblage of T. dorbigni in southern Brazil. Infection by Dioctophyme renale is typical of the urban area and suggest relation with eutrophication process and feedback of parasitic cycle in the freshwater urban environment. Parasitological indices of Neopolystoma sp. and T. achavali suggest to be occasional infections; whereas infection by Eustrongylides sp. could be considered accidental. About Telorchiidae, there was no co-occurrence of the species of this group for the examined hosts. In relation to host’s gender, it was observed that infections by S. contortus, F. affinis, C. emydidius and T. corti had higher rates in females, showing a more intimate association with the females of T. dorbigni. The results suggest that human impact on the environment could affect the infrapopulacional dynamics of parasite species influencing the presence and rates of infection of helminths or exacerbating heterogeneities related to host’s gender.

ABSTRACT Despite the great diversity of small insectivorous mammals and the use of scent gland secretions as a defense mechanism by harvestmen, there is no observation about the effectiveness of scent glands against predators such as small mammals. We report a remarkable harvestman defense mechanism against a small-mammal attack. When a harvestman and a mouse opossum confronted each other inside a cage, the harvestman knocked out the mouse opossum two sequential times before it could attack the harvestman. Although it is a unique observation and there is no information about its frequency in nature, this report stimulates the study of agonistic behavior between small, cryptic species, which are difficult to observe in the field.

ABSTRACT Given that many descriptions of Coleoptera were made with only external and superficial characters, an update to the original characterization of species is deemed necessary. This study focuses on updating the know morphological data for the adults of Omophoita octoguttata (Fabricius,1775) (Galerucinae, Alticini), a flea beetle native of southern Brazil. We also give insights on the morphology of its immature stages. The adult can be easily recognized by the pale macula at vertex, six large pale maculae, and two smaller in the humeral region at the elytra. The immatures are similar to other know Oedionychina. Eggs oval and orange. Mature larvae present setae bearing scoli, a reddened body, pygopod present, and lacking stemmata, but with curved hook-like tarsal claws. The pupae present slender black setae through its yellowed body, with the elytral and hind wing thecae curved around the body. The eggs are laid in small clutches in the soil and when the larvae eclode they stay in the aerial parts of plants. The mature larvae form a cocoon of soil matter around themselves for their pupal phase. Morphological remarks for larva and pupa of this species when compared to other members of the genus remain limited, demanding further studies with other species.

ABSTRACT Rodents and marsupials together, form the most rich group of mammals in Brazil, they are distributed in all biomes, including Atlantic Forest, and can be used to analyze environmental quality. The Araucaria Forest is a threatened formation of the Atlantic forest with few areas remaining intact and a huge lack of knowledge about the potential of its secondary forest fragments to act as habitat refuges to native fauna. This study evaluated the species richness and diversity of non-volant small mammals among five vegetation types within a protected area in an Araucaria Forest area from southern Brazil. The sampling was made in six bimonthly campaigns during a year, by pitfall and live traps. This effort resulted in 875 captures of 625 individuals from 16 species. The most common species in Pine Plantation was Oligoryzomys nigripes, in Natural Regeneration forest was Thaptomys nigrita and Akodon montensis was most often captured in the other vegetation. Although differences in species composition were found among the different vegetation types, there was no significant difference in species richness. Nevertheless, true diversity values were significantly lower in the Pine Plantation. The results demonstrated that the substitution of native for exotic vegetation generated a negative impact on the group diversity. More studies, in other Araucaria Forest areas are necessary to allow better understanding of the processes driving this loss of diversity in this biome threatened by antropic action.

ABSTRACT We studied the species composition of frogs in two phytophysiognomies within Pampa biome (grassland and forest) of a Ramsar site in southern Brazil to assess the distribution of species and dissimilarities in community composition on a small spatial scale. We tested the hypothesis that the vegetation structure and the types of land cover present in each physiognomy influence species distribution and the compositional dissimilarity patterns between locations. We sampled individuals using pitfall traps and active search in the areas around the traps. We evaluated the existence of these differences by using permutational multivariate analysis of variance and multivariate dispersion. We found that the compositional dissimilarity was higher between the sampling sites from different phytophysiognomies than within the same phytophysiognomy. Also, the difference in anuran species composition between the sampling sites within the forest was considerably high. These differences were mainly due to the type of land cover present in each sampled site. Based on our results, we could assume that the phytophysiognomies evaluated here offer quite different colonization opportunities for anurans, especially those related to microhabitat characteristics, such as microclimate variables. Still, the presence of different types of land cover seems to be a decisive factor for the maintenance of some anuran species, since these can serve as an important source for obtaining food resources, in addition to facilitating the dispersion of individuals within and between locals, serve as sites for the regulation of physiological functions and also refuges against predators.

ABSTRACT The Plant Stress Hypothesis predicts that stressed plants are more attacked by herbivorous insects. In this work, we investigated the influence of light stress on Crotalaria spectabilis Roth (Fabaceae) and on its main herbivore, the moth Utetheisa ornatrix (L., 1758) (Erebidae: Arctiinae). Specifically, we verified whether plants stressed by shading differ from non-stressed plants in terms of productivity, morphological characteristics and water percentage. We also evaluated the performance of moths in stressed and non-stressed plants. Seeds were sown in pots. When the plants reached 50 cm in height, they were randomly divided into two groups: stressed plants (treatment group) and non-stressed plants (control group). The stressed plants were covered by a black mesh, providing 50% of shading. Eight characteristics of stressed and non-stressed C. spectabilis plants were evaluated: height, fresh and dry aerial biomass, number of pods and seeds, leaf hardness, number of trichomes, leaf area, specific leaf mass and percentage of leaf water. Moths were raised individually on leaves of stressed and non-stressed plants and we obtained the larval survival, larval development time, pupal weight and female fecundity. The non-stressed plants had significantly higher percentage of water in the leaves, greater fresh aerial biomass and a higher number of trichomes than the stressed plants. The survival rate was 98% for larvae raised on leaves from stressed plants and 92% on leaves from non-stressed plants. The larval developmental time was significantly shorter and the weight of female pupae significantly higher in non-stressed plants than in stressed plants. Thus, the Plant Stress Hypothesis was only corroborated by two tested variables: number of trichomes (lower in stressed plants) and larval survival (higher in stressed plants). Trichomes are among the main types of plant defenses against herbivory and reducing their number on leaves would make stressed plants more susceptible to attack by moth larvae, a fact corroborated by a greater larval survival. One of the possible explanations for the lack of corroboration of the Plant Stress Hypothesis for most of the variables tested is that other characteristics can be changed under stress conditions, such as the concentration of secondary compounds.

ABSTRACT In this article are described two new species of oil-collecting bees of Centris (Melanocentris) from Colombia. Centris (Melanocentris) marinae sp. nov. occurs in the northeast, César Department, while C. (Melanocentris) germani sp. nov. occurs in the southeast, in the Caquetá, Meta and Vaupés Departments, as well as in the Amazonas State in northwestern Brazil. Photographs of both new species and a distribution map are also presented.

ABSTRACT This work aimed to assess the diversity and microhabitat use of benthic invertebrates in an urban forest stream in southeastern Brazilian region. The invertebrates were sampled in a headwater stream, located at the Tijuca Forest, Rio de Janeiro. Three types of microhabitats were sampled (litter, sand and stone) using a Surber sampler. Specimens were identified to the family-level and rarefaction curves were constructed for the total sampling and for each type of microhabitat. Community structure indices (abundance, taxonomic richness, diversity, and dominance) were calculated for each microhabitat. Differences among indices were tested through a repeated measure ANOVA, and differences among microhabitatsʼ composition through a PerMANOVA. A total of 9,800 specimens were registered in which Chironomidae was the most abundant. The rarefaction curves did not reach the asymptote. Community structure indices exhibited differences (RM ANOVA; p < 0.001), as well as microhabitats’ composition (PerMANOVA; p < 0.001). Abundance and taxonomic richness were the highest in litter, diversity was higher both in litter and stone, and sand had the highest dominance. Results highlighted that the variety of microhabitats may enhance local diversity and that the differences in resources availability of each type of microhabitat determine the distribution of these invertebrates.

RESUMO O aumento do conhecimento sobre a ecologia populacional das espécies de quelônios amazônicos é essencial para a recuperação e manutenção dos estoques naturais desses répteis. Neste estudo foi avaliada a influência de fatores hidroclimáticos sobre parâmetros populacionais e a condição corporal de Podocnemis expansa (Schweigger, 1812) em um trecho do Rio Formoso, sudeste da Amazônia brasileira, caracterizado pelo intenso uso das águas superficiais na irrigação de culturas agrícolas. O trabalho de campo ocorreu em três campanhas realizadas entre o final de julho e início de agosto dos anos de 2016, 2017 e 2018, totalizando um esforço amostral de 205 horas. Os indivíduos foram capturados por meio dos métodos de arrasto de rede, pesca com anzol e rede de espera; e os dados hidroclimáticos obtidos no site da Agência Nacional das Águas - ANA. Um total de 466 espécimes foi capturado e marcado, incluindo 47 machos adultos, 76 fêmeas adultas e 343 juvenis- revelando-se uma população composta predominantemente por juvenis (73,60%) e com razão sexual funcional desviada para as fêmeas (0,62:1). A redução no número de indivíduos das classes de tamanhos maiores e melhores condições corporais estiveram associadas, respectivamente, a uma maior vazão média do rio na estação seca e ao aumento da vazão no período chuvoso. Estudos futuros de longo prazo devem buscar aprofundar os conhecimentos sobre como fatores hidroclimáticos e as atividades agrícolas desenvolvidas na região afetam a demografia da espécie.

ABSTRACT Exploratory human activities have resulted in small fragments inserted into a matrix which is inhospitable to small non-flying mammals. The effects of landscape changes alter the distribution patterns of species. Landscape fragmentation patterns for small mammals are controversial, especially considering small fragments and ecotonal regions. Based on these arguments, we investigated the diversity patterns of small mammals in small fragments in the ecotonal Cerrado/Atlantic Forest region. A total of 24 fragments (<40 ha) were studied using tomahawk, sherman and pitfall traps. We found low species richness (11 species, six marsupials and five rodents), which was not expected because it is an ecotonal region. It was verified that composition and community structure are simplified by the marked presence of generalist species and with the increase of species turnover. The small forest fragments present a microhabitat structure with lianas and streams as main environmental filters of groups with ecological similarities. Our findings suggest that these fragments must be managed in order to conserve the local biodiversity and maintain the needed characteristics to enable the occurrence of different ecological groups.

RESUMEN Diversos estudios comparativos han demostrado que los hospedadores machos no sólo podrían albergar más parásitos que las hembras, sino también tener un rol en la estructura de la población de nematodes. Debido a esto, debatimos la función que tiene el sexo en el parasitismo en una población de anfibios en un sector del monte. Analizamos el contenido gastrointestinal en busca de endoparásitos de 43 ejemplares de Pleurodema nebulosum (Burmeister, 1861), 38 adultos (26 machos y 12 hembras) y 5 juveniles. Nuestros resultados indicaron que únicamente machos se encontraban parasitados asociado con una curva correspondiente a un modelo parasitismo/ rango - edad tipo III. Aplectana nebulosa Piñeiro-Gómez, González & Sanabria, 2017 (Nematoda: Cosmocercidae) presenta un patrón de distribución agregado ajustado a un modelo Poisson. Pleurodema nebulosum (Anura: Leptodactylidae) es oportunista para reproducirse en periodos de lluvia, debido a esto nosotros proponemos como hipótesis que el momento de infección por nematodes probablemente ocurra durante estos cortos periodos en lagunas temporales formadas. El parasitismo en machos podría estar relacionado a factores hormonales debido al periodo reproductivo. Por lo tanto el sexo sería un factor importante en la estructuración de las poblaciones parásitas de esta especie de anfibio.