Abstract Fire might occur under natural conditions in the Pantanal of Brazil; however, with climate change, severe periods of drought potentiated the devasting fires in 2020, resulting in substantial wildlife loss. Considering that mammal communities are strongly affected by fire and habitat alterations, the aim of this study was to evaluate possible differences in mammal diversity and the number of records before and one year after the fire in one region of the Pantanal of Mato Grosso, Brazil (Parque SESC Baía das Pedras - PSBP). The data collection was performed using camera trapping between 2015 and 2017 and 2021, together with visual field observations in PSBP. We observed that the mammal assemblage composition was similar before and one year after the fire. Four species were more or less frequent in burned areas than in unburned ones. Since the fire was controlled in this area, avoiding its total destruction, and the species that fled from the surrounding areas, which were completely burnt, might be using PSBP as a refuge while the vegetation recovers elsewhere. Therefore, the PSBP might have contributed to protecting mammal species after the fire and maintaining and conserving biodiversity on a regional scale in the Pantanal of Mato Grosso, Brazil.

Abstract In studies of avian diversity, many different methods have been applied. Since methodological approaches may affect research results, the choice of a given methodology must be consistent with the scientific objectives. The aim of this study was to investigate how different methodologies with their intrinsic limitations help detect and monitor birds to evaluate how they complement each other in the survey of species. Three different assessment methods, mist nets, point counts, and autonomous acoustic recordings were used to serve this purpose in a study of different Pantanal habitats, such as savannas and forests. The point counts detected more species (126 species) than the two other methods autonomous acoustic recordings (113 species) and mist nets (79 species). We observed significant differences in the number of species detected by mist nets and the other two methods. Each survey method identified exclusive species. When comparing habitats, all three methods showed significant differences in bird species composition. Savannas were richer in bird species than forests, and replacement was the main driver responsible for the differences in beta diversity between the habitats. The three methodologies, when applied together, proved to be complementary in avian species detection.

Abstract Knowledge of the reproductive biology of Bare-faced Curassows (BFC) from their natural habitats is very limited. Our study covers a two-and-a-half year breeding phenology on BFC in the northern Pantanal (Mato Grosso State, Brazil) with the main objective of collecting information on reproduction biology to contribute to future conservation management strategies of this cracid, which received a recent status of “High Conservation Priority”. The study was conducted at the SESC Pantanal, Baía das Pedras, Mato Grosso, Brazil (16°29′55″S, 56°24′46″W), a private protected area of approximately 4,200 ha. Between July 2015 and December 2017, 37 sampling locations were monitored with camera traps placed in a regular grid with a spacing of 1 km. Offspring were detected at least once at 8 locations, namely, in March, April, and May 2016 and in June, July, October, and November 2017, always together with parent(s). Territorial overlap between different family groups was detected. The camera trap dataset was supplemented by data from Citizen Science Projects (i.e., eBird) and the Global Biodiversity Information Facility (GBIF). Based on feather developmental stages and body size, offspring were classified into different age classes. Age determination indicates that breeding occurs year-round in the northern Pantanal region, supported by eBird and GBIF data. The use of a grid-based design for future camera-trapping studies of BFCs is strongly recommended. Our study is of biological relevance for conservation management projects since data were collected in an area with low anthropogenic disturbance and intact ecosystem services.

Abstract This study focuses on incubation parameters, egg morphometrics, and body mass development, hatching, and behavioral adaptations to heat stress within a colony of freshwater-breeding Black Skimmers (Rynchops niger) located in the private nature reserve of Serviço Social do Comércio (SESC) in the northern Pantanal, Mato Grosso, Brazil. Temperatures of nest, eggs, and surface substratum, as well as the development of embryos, were surveyed using thermal imaging, a method allowing digital recording from a distance and in a fraction of the time of traditional measuring techniques. The mean egg dimensions (n = 71) were 4.48 (± 0.13) × 3.27 (± 0.07) cm; the mean mass at hatching was 24.3 (± 1.9) g, with a significant decrease over incubation time. The mean surface temperature of eggs varied from 30.9℃ to 39.7℃, while the sand surface temperature was 20℃ at 06:00 h, rising to 47.7℃ at 11:00 h. There was a significant increase (7%) in egg surface temperature throughout incubation. Incubation-bout durations (n = 2108) were correlated with the microclimatic conditions of the substratum, becoming shorter with increasing sand-surface temperature around midday. Egg hatching lasted one day, and siblings hatched no more than 24 h apart. The mean body mass on Day 1 after hatching was 16.8 (± 1.6) g (n = 6). Three days after hatching, chicks moved to new sand depressions provided by parents near the original nest, where they remained motionless or tried to hide under riparian vegetation. The single chick that fledged had a growth rate of K = 0.117 and a t₁?₀₋₉₀ value of 37.3 days. On Day 7, dorsal pintail feathers and primaries appeared, which were open on Day 15. After 14 days, the chick was able to regulate its body temperature, and no more feeding by parental birds during the daytime was observed. On Day 21, the immature plumage was fully developed. Fledging was completed on Day 27. Our study demonstrates that thermal imaging is a useful method of surveying egg and embryo development in the Black Skimmer, reducing nest disturbance and observation efforts.

Resumo: O estudo de assembleias de coleópteros associadas às copas de florestas tropicias contribui para a expansão do conhecimento sobre a diversidade de espécies e os padrões ecológicos relacionados à distribuição dessa diversidade em ambientes tropicais, incluindo áreas úmidas como o Pantanal brasileiro. Nesse cenário, o presente estudo avaliou o efeito da variação temporal sobre a abundância, riqueza e distribuição da assembleia de Coleoptera associada às copas de Callisthene fasciculata (Spr.) Mart. (Vochysiaceae) ao longo dos períodos de seca e cheia na região norte do Pantanal de Mato Grosso, Brasil. Doze exemplares de C. fasciculata foram amostrados entre 2010 e 2011, seis por período sazonal, utilizando-se termonebulização com inseticida. Um total de 1.663 coleópteros foram coletados, consistindo em 1.572 adultos e 91 larvas. Os adultos se distribuem em 38 famílias e 251 espécies e morfoespécies. Chrysomelidae, Curculionidae, Nitidulidae e Tenebrionidae predominaram em termos de abundância e riqueza. A distribuição das famílias, abundância, riqueza de espécies e agrupamentos em guildas tróficas variaram entre os períodos de seca e cheia, evidenciando uma estreita relação com as condições fenológicas de C. fasciculata ocasionadas pelo efeito sazonal dessa região. Conclui-se que a sazonalidade imposta pelo regime hidrológico do Pantanal e sua influência sobre a fenologia de C. fasciculata afetam a estrutura da assembleia de coleópteros associados às copas nessa formação monodominante no Pantanal de Mato Grosso.

Abstract: The study of coleopteran assemblages associated with the canopies of tropical forests can help to expand the knowledge about species diversity and the ecological patterns related to the distribution of this diversity in tropical environments, including wetlands such as the Brazilian Pantanal. In this scenario, the present study examined the effect of temporal variation on the abundance, richness and distribution of the Coleoptera assemblage associated with canopies of Callisthene fasciculata (Spr.) Mart. (Vochysiaceae) throughout the dry and high-water seasonal periods in the Northern Pantanal of Mato Grosso, Brazil. Twelve specimens of C. fasciculata were sampled between 2010 and 2011, six per seasonal period, by thermal fogging with insecticide. A total of 1,663 coleopterans were collected, consisting of 1,572 adults and 91 larvae. The adults are distributed into 38 families and 251 species or morphospecies. Chrysomelidae, Curculionidae, Nitidulidae and Tenebrionidae predominated in terms of abundance and richness. Family distribution, abundance, species richness and trophic guilds varied between the dry and high-water periods, demonstrating a relationship with the phenological conditions of C. fasciculata in addition to seasonality effect. In conclusion, the seasonality imposed by the hydrological regime and its influence on the phenology of C. fasciculata affect the structure of the coleopteran assemblage associated with the canopy of this monodominant vegetation formation in the Pantanal of Mato Grosso.

Resumen Los estudios sobre artrópodos asociados a las copas de árboles en bosques tropicales contribuyen a comprender la dinámica de comunidades de dosel y su relación con la estructura y función de este importante ecosistema. Este estudio evaluó la composición de la comunidad de artrópodos en copas de árboles de Callisthene fasciculata en bosques monodominantes de esta especie, a lo largo de dos períodos estacionales, inundación y sequía, en la región norte del Pantanal de Mato Grosso, Brasil, como parte de un proyecto sobre artrópodos del dosel en bosques monodominantes en esta región. Los muestreos fueron realizados en 12 individuos de C. fasciculata, seis en periodo de inundación (2010) y seis en época seca (2011), aplicando el método de termonebulización de copas con insecticida. Un total de 28.197 artrópodos fue recolectado. Hymenoptera (Formicidae, en su mayoría), Diptera, Acari, Thysanoptera, Hemiptera y Coleoptera fueron los grupos más representativos. A pesar que los análisis no demostraron variación en la abundancia de individuos entre los períodos de inundación y sequía; la comunidad de artrópodos varió significativamente en función de la distribución de los taxones que la componen. Los opiliones y escorpiones se registraron únicamente durante el período de inundación, mientras que Polyxenida y Strepsiptera solo durante el periodo seco. Thysanoptera fue el orden más abundante en la época seca, lo que evidencia la relación con el inicio del periodo de floración de C. fasciculata. En general, durante los periodos estacionales de sequía e inundación estos árboles mantienen comunidades distintas de artrópodos. La variación temporal impuesta por el régimen hídrico del Pantanal afecta la fenología de las especies vegetales como C. fasciculata lo que altera, consecuentemente, la composición de las comunidades de artrópodos asociadas al dosel de estas manchas monodominantes en el Pantanal de Mato Grosso.

Abstract Studies on arthropods associated with tropical rainforest canopies contribute to a further understanding of forest canopy community dynamics and their relationship to the structure and function of this ecosystem. This study evaluated arthropod community composition in monodominant Callisthene fasciculata forest canopy throughout the high water and dry periods in the northern region of the Pantanal in Mato Grosso, Brazil, as a part of a project about arboreal canopy arthropods associated with monodominant areas in this region. Sampling was conducted on 12 individuals of C. fasciculata, six from the high-water season (2010) and six from the dry season (2011), using insecticide fogging. A total of 28,197 arthropods were collected. Hymenoptera (the majority being Formicidae), Diptera, Acari, Thysanoptera, Hemiptera and Coleoptera, were the most representative groups. Although the analysis did not show variation in the abundance of individuals between the high water and dry seasons, the arthropod community varied significantly in taxa composition. Opiliones, Embioptera, Ephemeroptera and Scorpiones occurred only during the high-water period, with Polyxenida and Strepsiptera occurring only in the dry season. Thysanoptera was more abundant in the dry season, showing a relationship with the beginning of the C. fasciculata flowering period. In general, the high water and dry seasons maintain distinct communities in this habitat, illustrating how the temporal variation in the phenology of C. fasciculata imposed by the Pantanal’s hydrological regime alters the composition of the associated arthropod communities in the canopy of these monodominant formations in the Pantanal of Mato Grosso.

Resumo: O Pantanal de Mato Grosso é uma das maiores e mais importantes planícies de inundação do mundo, em relação à sua biodiversidade e aos seus indispensáveis serviços ecológicos em escalas locais, regionais e globais. Apesar dessa importância, existem, ainda, muitas lacunas sobre o conhecimento de sua biodiversidade, bem como de seus mecanismos geradores e mantenedores. Desse modo, a fim de contribuir com o conhecimento de sua diversidade biológica compilamos, com base na literatura e em espécimes disponíveis nas coleções e acervos zoológicos da Universidade Federal de Mato Grosso-UFMT, uma lista de espécies de miriápodes (Arthropoda, Myriapoda) ocorrentes no Pantanal de Poconé, Mato Grosso, Brasil. Um total de 33 espécies de Myriapoda foi registrado como ocorrentes nessa região. As espécies de Diplopoda (20 spp.; 60,6%), estão distribuídas em quatro ordens. Polydesmida está representada por cinco famílias, com destaque para Chelodesmidae com três espécies, Paradoxosomatidae e Pyrgodesmidae, com duas espécies cada, além de Cyrtodesmidae e Fuhrmannodesmidae, com uma espécie cada, recentemente registradas para essa região; Spirostrepida representada por Spirostreptidae, com oito espécies; Spirobolida, com duas espécies (uma Rhinocricidae e uma não identificada); e Polyxenida. Os Chilopoda (10 spp.; 30,3%) estão distribuídos em três ordens: Scolopendromorpha, com quatro espécies da família Scolopendridae, duas espécies de Scolopocryptopidae e uma espécie de Cryptopidae; Geophilomorpha, com as famílias Aphilodontidae e Schendylidae, com uma espécie cada; e Lithobiomorpha, com uma única espécie de Henicopidae. Symphyla foi representada por apenas duas espécies (6,1%) da família Scutigerellidae e Pauropoda (3,0%) por uma única espécie de Pauropodidae. A riqueza de espécies de Myriapoda, bem como a alta proporção de novos registros em estudos recentes, reforçam a importância da região norte do Pantanal como um centro de diversidade com potencial prioridade às medidas de conservação de seus variados habitats.

Abstract: The Brazilian Pantanal biome is one of the largest and most important floodplains in the world by virtue of its biodiversity and indispensable ecological services on local, regional, and global scales. Despite this importance, many gaps remain concerning its biodiversity as well as its generation and maintenance mechanisms. In view of expanding the information about its biological diversity, we compiled a list of Myriapoda (Arthropoda) species occurring in the Pantanal of Poconé, Mato Grosso, Brazil, based on the records from literature and on the specimens available in the zoological collections of Federal University of Mato Grosso -UFMT. A total of 33 Myriapoda species were recorded in the region. The Diplopoda species (20 spp.; 60.6%) are distributed 'between four orders: Polydesmida, represented by five families (Chelodesmidae, notably, with three species; Paradoxosomatidae and Pyrgodesmidae, with two species each; and Cyrtodesmidae and Fuhrmannodesmidae, with one species each, recently recorded in the region); Spirostreptida, represented by Spirostreptidae, with eight species; Spirobolida, with two species (one Rhinocricidae and one not identified); and Polyxenida. The Chilopoda (10 spp.; 30.3%) belong to three orders: Scolopendromorpha, with four species of the family Scolopendridae, two Scolopocryptopidae species, and one Cryptopidae species; Geophilomorpha, with the families Aphilodontidae and Schendylidae, with one species each; and Lithobiomorpha, with one Henicopidae species. Symphyla was represented by only two species (6.1%) of the family Scutigerellidae; and Pauropoda (3.0%) by a single species of Pauropodidae. The Myriapoda species richness, as well as the high number of new records in recent studies reinforce the importance of the northern region of the Pantanal biome as a diversity center with potential priority for measures aimed at the conservation of its many habitats.

Resumo: Os miriápodes constituem importantes táxons da macrofauna edáfica atuando em diferentes níveis tróficos, influenciando a dinâmica desses ambientes. Este estudo avaliou a variação na composição, riqueza e abundância da assembleia de miriápodes edáficos em função da distribuição e estrutura de habitats inundáveis e não inundáveis (variação espacial) e da sazonalidade hidrológica (variação temporal) em uma planície de inundação na região norte do Pantanal de Mato Grosso, Brasil. As amostragens foram realizadas em três áreas no Pantanal de Poconé, em um gradiente altitudinal e de inundação, constituídas por habitats inundáveis e não inundáveis e por diferentes formações vegetacionais. Em cada tipo de habitat foram delimitados três quadrantes (10 x 10 m), onde foram efetuadas amostragens com armadilhas pitfall e Extrator mini-Winkler, ao longo dos períodos de seca, enchente, cheia e vazante, durante dois ciclos hidrológicos do Pantanal (2010/2011 e 2011/2012). Foram amostrados 549 miriápodes, dos quais 407 Diplopoda e 142 Chilopoda, distribuídos em seis ordens, 12 famílias e 20 espécies. A composição da assembleia variou ao longo dos períodos sazonais, indicando que a enchente e seca diferem da cheia e vazante. Além da variação entre os períodos sazonais, a riqueza e abundância de miriápodes variaram também em relação às áreas, constituídas por diferentes formações vegetacionais. Assim, pode-se concluir que a sazonalidade hidrológica associada ao gradiente de inundação e os diferentes tipos vegetacionais foram determinantes para a distribuição espacial e temporal heterogênea da assembleia de miriápodes, evidenciando que a conservação destes invertebrados no Pantanal está diretamente ligada à preservação da vegetação e, consequentemente, de sua integridade ecossistêmica.

Abstract: Myriapods constitute important edaphic macrofauna taxa which dwell in different trophic levels and influence the dynamics of these environments. This study evaluated the variation in composition, richness and abundance of edaphic myriapod assemblages as a function of the distribution and structure of flooded and non-flooded habitats (spatial variation) and hydrological seasonality (temporal variation) in a floodplain of the northern Pantanal region of Mato Grosso, Brazil. Sampling was carried out in three areas of the Poconé Pantanal, along an altitudinal and inundation gradient consisting of inundated and non-inundated habitats and different vegetation formations. Three quadrats (10 x 10 m) were delimited within each habitat type, where sampling was performed using pitfall traps and mini-Winkler extractors during the dry, rising water, high water and receding water periods of two hydrological cycles within the Pantanal (2010/2011 and 2011/2012). A total of 549 millipedes were collected, consisting of 407 Diplopoda and 142 Chilopoda distributed in six orders, 12 families and 20 species. The assemblages composition varied throughout the seasonal periods, indicating that the rising water and dry periods differed from the high water and receding water periods. In addition to the variation between seasonal periods, myriapod richness and abundance also varied in relation to areas consisting of different vegetation formations. Thus, it can be concluded that the hydrological seasonality associated with the inundation gradient and different vegetation types were determinant in the heterogeneous spatial and temporal distribution of myriapod assemblages, validating that the conservation of these invertebrates in the Pantanal is directly linked to the preservation of vegetation, and consequently, ecosystem integrity.

ResumenLos Pseudoescorpiones comprenden un diversificado grupo de arácnidos con aproximadamente 3 500 especies que se han encontrado en varios hábitats como suelo, hojarasca, cuevas y copas de árboles. Este estudio tiene como objetivo evaluar la relación entre la comunidad de Pseudoscorpiones presentes en el suelo, nidos de termitas (termiteros), troncos y copas de árboles, así como también la distribución temporal de la abundancia y riqueza de especies en estos hábitats. Para esto, se usaron diferentes técnicas de muestreo en hábitats de un Bosque Monodominante Estacionalmente Inundado en la región norte del Pantanal, Estado Mato Grosso, Brasil. Datos referentes a abundancia y riqueza de especies del ensamble fueron ordenados por Escalamiento Multidimensional No Métrico (NMDS). Fueron capturados 2 068 Pseudoscorpiones distribuidos en siete familias y 18 especies. Chernetidae (8 spp.) y Withiidae (5 spp.) predominaron. Mientras Atemnidae, Cheiridiidae, Geogarypidae, Lechytiidae y Olpiidae fueron registradas con una especie en cada una. La fauna terrícola fue más abundante (1 035 ind.; 50.0 % de la captura total), con tres familias y 10 especies. Para la fauna arborícola (712 ind.; 34.4 %), cuatro familias y 13 especies fueron registradas. Los termiteros (321 ind.; 15.6 %) representaron el hábitat con menor número de individuos; sin embargo, fueron identificadas cinco familias y nueve especies, incluyendo Parachernes sp. 2, Geogarypus sp. y Olpiolum sp., que no se encuentra en otros hábitats analizados en este bosque. Los análisis estadísticos no evidenciaron variación temporal en la distribución de abundancia y riqueza de Pseudoscorpiones en cada hábitat evaluado; no obstante, demostraron que el ambiente edáfico (suelo y termiteros), troncos y copas de árboles son distintos en relación a la composición de la comunidad. La presencia de especies típicamente terrícolas (e.g. Parawithius sp., Withiidae gen. sp. y Parachernes sp.) y otras arborícolas (e.g. Cheiridium sp., Americhernes sp. y Lustrochernes sp.) evidencian una estratificación vertical de la comunidad de Pseudoscorpiones presente en Bosques Inundables del Pantanal brasileño.

AbstractPseudoscorpions embrace a diverse group of arachnids with approximately 3 500 species that occur in various habitats, such as soil, leaf litter, caves and canopies. This study aimed at evaluating the relationship between the pseudoscorpion assemblages in soil, termite nests, tree trunks and canopies, as well as the temporal distribution as to the abundance and richness of species in these habitats. For this purpose different sampling techniques were applied in an integrated manner in distinct habitats of a seasonally flooded monodominant forest in the Northern Pantanal of Mato Grosso, Brazil. Data regarding the abundance and richness of assemblage species were organized by means of the Non-Metric Multidimensional Scaling (NMDS). A total of 2 068 Pseudoscorpiones distributed in seven families and 18 species were captured. Chernetidae (8 spp.) and Withiidae (5 spp.) predominated, while Atemnidae, Cheiridiidae, Geogarypidae, Lechytiidae and Olpiidae were present with only one species each. Terrestrial fauna was more abundant (1 035 ind.; 50.0 % of the total catch) with three families and 10 species. In the arboreal fauna (712 ind.; 34.4 %), four families and 13 species were found. Termite mounds (321 ind.; 15.6 %) corresponded to the habitat with the least number of individuals, however, five families and nine species were identified, including Parachernes sp. 2, Geogarypus sp. and Olpiolum sp., not found in other analyzed habitats in this forest. The analyses did not show any temporal variation as to abundance or richness of Pseudoscorpiones in each evaluated habitat; however, the analysis showed that the edaphic environment (soil + termite nests), tree trunks and tree canopies are distinct habitats in relation to the composition of the assemblage. The occurrence of typical terricolous (e.g. Parawithius sp., Withiidae gen. sp. and Parachernes sp.) and other arboricolous (e.g. Cheiridium sp., Americhernes sp. and Lustrochernes sp.) species highlights the vertical stratification of the assemblage present in this floodplain forest in the Pantanal of Mato Grosso.

RESUMO Analisou-se a concentração de fenóis totais presentes nas folhas de Vochysia divergens Pohl. (Vochysiaceae) na região norte do Pantanal, coletadas entre setembro de 2012 e junho de 2013, compreendendo o período de seca (setembro/2012), o começo do período de inundação (dezembro/2012), período de cheia (março/2013) seguido pela vazante (junho/2013). Para a coleta foram selecionadas 15 árvores, cinco em cada área amostral. A concentração de fenóis nas folhas foi obtida com as amostras secas à 40ºC, maceradas com etanol: água e centrifugada. O extrato foi usado para determinação da concentração de fenóis totais utilizando-se o método espectrométrico de Folin-Ciocalteu. Não houve diferença entre as áreas amostrais, entretanto os valores foram diferentes em relação aos períodos sazonais. A menor concentração foi registrada no período da seca (folhas jovens) aumentando gradativamente no início do período de enchente com maiores níveis no final do período de inundação. A maior concentração de fenóis ocorreu durante a vazante (final do ciclo de vida das folhas de V. divergens), seguida pela cheia e enchente. O aumento na concentração de fenóis, provavelmente, está associado ao ciclo de inundações do Pantanal, e relacionado com a fenologia das folhas de V. divergens.

ABSTRACT The total phenol concentration present in Vochysia divergens Pohl. (Vochysiaceae) leaves in the Pantanal was analyzed. Work was carried out between September/2012 and June/2013 which is made up by the dry season (September/2012), the beginning of the rising water (December/2012), the high water (March/2013) followed by the receding water period (June/2013). For the purpose of the research fifteen trees were selected, five from each sample area. The phenolic content in the leaves was obtained from the samples which were dried, steeped with ethanol: water and centrifuged. The extract was used to determine the concentration of total phenols using the Folin-Ciocalteu spectrometric method. There was no difference among the sampling areas; however the values were different in relation to seasonal periods. The lowest concentration was recorded in the dry season (young leaves) increasing gradually at the beginning of the rising water, with higher levels at the end of high water and receding water season. The highest concentration of phenols occurred during the receding water period (end of the life cycle of V. divergens leaves), followed by high and rising water periods. The increase in phenol concentration is associated with the Pantanal flood cycle, and related to the phenology of the V. divergens leaves.

A teoria plastrão foi testada em adultos de Neochetina eichhorniae Warner, 1970, por meio da análise da estrutura que reveste o tegumento destes insetos e em experimentos laboratoriais de submersão. Os processos tegumentares foram reconhecidos em três tipos: escamas aglutinadas e com perfurações largas; escamas plumosas de tamanhos e formas variadas; e pêlos. Os experimentos realizados com 264 indivíduos adultos os quais permaneciam submersos por diferentes intervalos de tempo (n = 11) e em dois tratamentos, água natural não aerada e água previamente fervida, com quatro repetições para cada tratamento, revelaram uma mortalidade máxima após 24 horas de mergulho no tratamento água previamente fervida. A sobrevivência dos adultos foi negativa e significativamente correlacionada com os tratamentos empregados e entre os diferentes intervalos de tempo. Os valores de oxigênio dissolvido (mg/l) na água diferiram significativamente entre os tratamentos aplicados, sendo positivamente correlacionado com a sobrevivência dos adultos nos dois tratamentos, embora mais acentuadamente no tratamento com água previamente fervida. A mortalidade dos adultos após 24 horas de mergulho no tratamento com água previamente fervida pode estar associada às condições físico-químicas da água não testadas neste estudo, como, por exemplo, baixa tensão superficial e concentração de solutos. Estes resultados sugerem uma funcionalidade do plastrão nos adultos desta espécie.

The plastron theory was tested in adults of Neochetina eichhorniae Warner, 1970, through the analysis of the structure that coats these insects' integument and also through submersion laboratorial experiments. The tegument processes were recognized in three types: agglutinated scales with large perforations, plumose scales of varied sizes and shapes, and hairs. The experiments were carried out on 264 adult individuals which were kept submerged at different time intervals (n = 11) and in two types of treatment, natural non-aerated water and previously boiled water, with four repetitions for each treatment. The tests showed a maximum mortality after 24 hours of immersion in the previously boiled water treatment. The survival of the adults was negative and significantly correlated with the types of treatment employed and within the different time intervals. The values of oxygen dissolved in water (mg/l) differed significantly within the types of treatment employed. They were positively correlated with the survival of the adults in the two types of treatment, although more markedly in the treatment with previously boiled water. The mortality of adults after 24 hours of submersion in the treatment with previously boiled water may be associated with the physical-chemical conditions of the non-tested water in this study, such as low surface tension and concentration of solutes. These results suggest plastron functionality in the adults of this species.

Este estudo teve como objetivo avaliar a composição da comunidade edáfica de Araneae de uma floresta sazonalmente inundável na região norte do Pantanal de Mato Grosso, tendo como base sua densidade de atividade e emergência. Foram empregadas armadilhas de solo tipo pitfall-trap para avaliação da atividade sobre o solo, e fotoecletores de solo para verificar a densidade de emergência ao longo de todos os períodos sazonais desta região, entre janeiro de 2004 e janeiro de 2005. Como resultado obteve-se um total de 2.233 aranhas, 1.314 indivíduos obtidos com armadilhas pitfall (29 famílias e 35 gêneros) e 919 com fotoecletores de solo (27 famílias e 22 gêneros). Oonopidae (335 ind.: 15,0%), Corinnidae (310 ind.; 13,9%), Gnaphosidae (289 ind.; 12,9%) e Ctenidae (248 ind.; 11,1%) corresponderam às principais representantes desta comunidade, bem como àquelas com maior densidade de atividade sobre a superfície do solo, enquanto Salticidae (177 ind.; 19,3%), Oonopidae (126 ind.; 13,7%) e Gnaphosidae (114 ind.; 12,4%) foram aquelas com maior densidade de emergência. Doze agrupamentos de guildas comportamentais foram identificados, sete representaram aranhas caçadoras e cinco tecelãs. As análises referentes à variação temporal da atividade e emergência desta comunidade evidenciaram que a influência de fatores abióticos como a pluviosidade e a inundação da floresta são determinantes para sua estruturação, influenciando a ocorrência de táxons como Salticidae, Corinnidae e Oonopidae.

This study aimed to evaluate the community composition of ground dwelling Araneae in a seasonally flooded forest in the Northern region of Pantanal of Mato Grosso, based on its density and emergency activity. Pitfall traps were used to estimate the ground activity and ground photoeclectors to verify the density of emergency throughout the seasonal periods between January 2004 and January 2005. A total of 2,233 spiders were collected, 1,314 with pitfall traps (29 families and 35 genera) and 919 with ground photoeclectors (27 families and 22 genera). Oonopidae (335 ind.: 15,0%), Corinnidae (310 ind.; 13,9%), Gnaphosidae (289 ind.; 12,9%) and Ctenidae (248 ind.; 11,1%) were the main representatives of the community, as well as those with higher density of activity on the soil surface, while Salticidae (177 ind.; 19,3%), Oonopidae (126 ind.; 13,7%) and Gnaphosidae (114 ind.; 12,4%) were those with higher density of emergency. Twelve groups of behavioral guilds were identified, seven were hunting spiders and five were weavers. The analyses concerning temporal variation of the activity and emergence of this community demonstrate that the influence of abiotic factors, such as rainfall and flooding of the forest, are determinant to its structure, influencing the occurrence of groups as Salticidae, Corinnidae and Oonopidae.

São apresentados, pela primeira vez para o Brasil, dados sobre a ocorrência de dez espécies de curculionídeos associadas à Pistia stratiotes L. (Araceae), provenientes da Ilha de Marchantaria, Manaus (Amazonas, Brasil). Durante o período de março a agosto de 2005 foram amostrados 809 espécimens de curculionídeos sobre P. stratiotes, distribuídos em nove espécies alocadas em cinco gêneros de Stenopelmini, e uma espécie não identificada pertencente à Cryptorhynchinae. Dentre os Stenopelmini, Argentinorhynchus breyeri Brèthes, 1910 (N = 665) foi a espécie dominante, com a maior abundância em julho (N = 189), e a menor em agosto (N = 11); Ochetina uniformis Pascoe, 1881 (N = 63), Neochetina bruchi Hustache, 1926 (N = 45), Neohydronomus pulchellus Hustache, 1926 (N = 15), Neohydronomus affinis Hustache, 1926 (N = 10), A. squamosus (Hustache, 1926) (N = 5), Neochetina eichhorniae Warner, 1970 (N = 4), A. minimus O'Brien & Wibmer, 1989b (N = 1) e Tanysphiroideus sp. (N = 1) apresentaram abundância inferior. Além disto, registra-se para o Brasil a co-ocorrência de A. breyeri, A. minimus e A. squamosus sobre P. stratiotes, e para o estado do Amazonas, o primeiro registro de A. minimus e A. squamosus.

Data on the occurrence of ten weevils species associated with Pistia stratiotes L. (Araceae), from Ilha de Marchantaria, Manaus (Amazonas, Brazil) are presented for the first time. During the period from March to August 2005, 809 weevils specimens were sampled on P. stratiotes, distributed across nine species allocated in five genera of Stenopelmini, in addition to one unidentified species in the Cryptorhynchinae. Among the Stenopelmini, Argentinorhynchus breyeri Brèthes, 1910 (N = 665) was the dominant species, with the highest abundance in July (N = 189) and the lowest in August (N = 11), while Ochetina uniformis Pascoe, 1881 (N = 63), Neochetina bruchi Hustache, 1926 (N = 45), Neohydronomus pulchellus Hustache, 1926 (N = 15), Neohydronomus affinis Hustache, 1926 (N = 10), A. squamosus (Hustache, 1926) (N = 5), Neochetina eichhorniae Warner, 1970 (N = 4), A. minimus O'Brien & Wibmer, 1989b (N = 1), and Tanysphiroideus sp. (N = 1) had lower abundances. In addition, the co-occurrences of A. breyeri, A. minimus, and A. squamosus on P. stratiotes were recorded for Brazil and the first records of A. minimus and A. squamosus were observed for the State of Amazonas.

O comportamento de nado exibido por indivíduos de L. fasciatus e O. uniformis foi analisado quadro a quadro através de imagens obtidas com o auxílio de uma câmera fotográfica digital com opção de vídeo, acoplada a um estereomicroscópio. Foi demonstrado que O. uniformis, espécie aquática, nada com o auxílio dos três pares de pernas. Durante este processo a maior parte do abdome e rostro localizam-se abaixo da superfície da água, parte das tíbias anteriores e posteriores acima da superfície, enquanto as médias permanecem submersas durante o nado. As pernas metatorácicas, durante a "braçada", impulsionam fracamente o inseto para frente, enquanto que as mesotorácicas são as responsáveis por uma maior propulsão. As pernas protorácicas, estendidas anteriormente, ajudam na orientação do nado. A espécie L. fasciatus, de hábito semi-aquático, apresenta o mesmo estilo de nado como em O. uniformis, também realizado com auxilio dos três pares de pernas, sendo as mesotorácicas, responsáveis pela maior propulsão. O corpo do inseto permanece na superfície da água durante todo o processo, porém as pernas encontram-se mergulhadas. Ambas as espécies, O. uniformis e L. fasciatus, completam um ciclo do nado em cerca de 0,33 e 0,32 segundos, respectivamente, com uma velocidade média de 1,38 cm/s e tempo máximo e mínimo de permanência de nado 11,15 e 5,05 minutos, respectivamente, para L. fasciatus. O comportamento de nado exibido por O. uniformis e L. fasciatus corresponde ao estilo de nado conhecido como manobra semelhante ao nado peito (breast strok-like maneuver). Trata-se do primeiro registro para ambas as espécies elevando para sete o número de gêneros de Curculionidae conhecidos com tal comportamento.

The swimming behavior exhibited by specimens of L. fasciatus and O. uniformis was analyzed frame-by-frame with video observation recorded with a digital camera, attached to a stereomicroscope. Adults of O. uniformis, an aquatic insect, swim with all three pairs of legs. During the process of swimming the majority of the abdomen and rostrum remain submerged, part of the fore and hind tibiae remain above the surface, while the mid tibiae remain submerged. The mesothoracic legs, during the power-stroke stage, provide the greatest thrust while the metathoracic legs provide the least forward propulsion. The prothoracic legs, extended forward, help to direct the swimming. The semi-aquatic specie L. fasciatus shows the same swimming style as O. uniformis, that is, with movement of all the three pairs of legs; the mesothoracic legs are responsible for the main propulsion. The insect body remains on the water surface during the process of swimming, while the legs remain submerged. Both species complete a swimming cycle in 0.33 and 0.32 seconds, respectively, with an average speed of 1.38 cm/s and a maximum and minimum swimming duration time of 11.15 and 5.05 minutes, respectively, for L. fasciatus. The swimming behavior exhibited by O. uniformis and L. fasciatus corresponds to the style known as a breast strokelike maneuver. This is the first record of this kind of swimming for both species here observed and increases to seven the number of genera of Curculionidae exhibiting this behavior.

Artrópodes terrestres associados a copas de árvores no Pantanal de Mato Grosso, Brasil. Este estudo representa uma contribuição ao conhecimento da diversidade de artrópodes associados à copa de Vochysia divergens Pohl (Vochysiaceae). Três indivíduos foram amostrados durante dois períodos sazonais, um durante a cheia (árvore A: fevereiro) utilizando-se o método de pulverização com inseticida e dois durante a seca (árvore B: setembro, C: outubro), empregando-se a termonebulização. Um total de 15744 artrópodes (183,2±38,9 individuos/m²) foram obtidos em 86m² de área representando 20 ordens taxonômicas, 87,1% Insecta e 12,9% Arachnida. O grupo dominante foi Hymenoptera (48,5%; 88,9 individuos/m²), a maioria Formicidae (44,5%; 81,4 individuos/m²), seguido por Coleoptera (14,0%; 25,5 individuos/m²) e Araneae (10,2%; 19,5 individuos/m²), que representaram 62,5% do total coletado. Com relação a freqüência, 14 de todas as ordens (70%) ocorreram nas tres árvores. Dermaptera, Isoptera, Neuroptera, Odonata, Plecoptera e Trichoptera foram coletadas em uma única árvore. Foram obtidos 2197 Coleoptera adultos (25,5±11,3 indivíduos/m²), sendo 99% assinalados para 32 famílias e 256 morfoespécies. Nitidulidae (17,9%; 4,6 indivíduos/m²), Anobiidae (16,7%; 4,3 indivíduos/m²), Curculionidae (13,2%; 3,4 indivíduos/m²) e Meloidae (11,4%; 2,9 indivíduos/m²) foram dominantes. Os Coleoptera adultos associados à copa de V. divergens indicam dominancia de herbívoros (37,8% do total coletado, 127 spp.) e predadores (35,2%, 82 spp.), seguidos por saprófagos (16,2%, 32 spp.) e fungívoros (10,8%, 15 spp.). A influência do pulso de inundação sobre a comunidade de artrópodes arbóreos associados à V. divergens é indicada pela variação sazonal nos grupos avaliados, gerando mudanças em sua estrutura e composição ao longo dos períodos sazonais.

Terrestrial arthropods from tree canopies in the Pantanal of Mato Grosso, Brazil. This study represents a contribution to the knowledge of the diversity of arthropods associated to the canopy of Vochysia divergens Pohl (Vochysiaceae). Three trees individuals were sampled during two seasonal periods in this region: a) by spraying one tree canopy during high water (February); b) by fogging two tree canopies during low water (September/October). The 15,744 arthropods (183.2±38.9 individuals/m²) obtained from all three trees (86 m²) represented 20 taxonomic orders, 87.1% were Insecta, and 12.9% Arachnida. The dominant groups were Hymenoptera (48.5%; 88.9 individuals/m²), mostly Formicidae (44.5%; 81.4 individuals/m²), followed by Coleoptera (14.0%; 25.5 individuals/m²) and Araneae (10.2%; 19.5 individuals/m²), together representing 62.5% of the total catch. Fourteen (70%) of all orders occurred on three trees. Dermaptera, Isoptera, Neuroptera, Odonata, Plecoptera and Trichoptera were collected from only one tree. Of the total, 2,197 adult Coleoptera collected (25.5±11.3 individuals/m²), 99% were assigned to 32 families and 256 morphospecies. Nitidulidae (17.9% of the total catch; 4.6 individuals/m²), Anobiidae (16.7%; 4.3 individuals/m²), Curculionidae (13.2%; 3.4 individuals/m²) and Meloidae (11.4%; 2.9 individuals/m²) dominated. The communitiy of adult Coleoptera on V. divergens indicated a dominance of herbivores (37.8% of the total catch, 127 spp.) and predators (35.2%, 82 spp.), followed by saprophages (16.2%, 32 spp.) and fungivores (10.8%, 15 spp.). The influence of the flood pulse on the community of arboreal arthropods in V. divergens is indicated by the seasonal variation in evaluated groups, causing changes in their structure and composition.