Neutral and outlier single nucleotide polymorphisms disentangle the evolutionary history of a coastal Solanaceae species.

Speciation begins with the isolation of some individuals or subpopulations due to drivers promoting a diverging genetic distribution. Such isolation may occur, followed by different processes and pressures. Isolation-by-distance (IBD), isolation-by-adaptation (IBA), and isolation-by-colonization (IBC) have been recognized as the main divergence patterns. Still, it is not easy to distinguish which one is the main pattern as each one may act at different points in time or even simultaneously. Using an extensive genome coverage from a Petunia species complex with coastal and inland distribution and multiple analytical approaches on population genomics and phylogeography, we showed a complex interplay between neutral and selective forces acting on the divergence process. We found 18,887 SNPs potentially neutral and 924 potentially under selection (outlier) loci. All analyses pointed that each subspecies displays its own genetic component and evolutionary history. We suggested plausible ecological drivers for such divergence in a southernmost South Atlantic coastal plain in Brazil and Uruguay and identified a connection between adaptation and environment heterogeneity.

Landscape and climatic features drive genetic differentiation processes in a South American coastal plant.

BACKGROUND: Historical and ecological processes shape patterns of genetic diversity in plant species. Colonization to new environments and geographical landscape features determine, amongst other factors, genetic diversity within- and differentiation between-populations. We analyse the genetic diversity and population structure of Calibrachoa heterophylla to infer the influence of abiotic landscape features on the level of gene flow in this coastal species of the South Atlantic Coastal Plain. RESULTS: The C. heterophylla populations located on early-deposited coastal plain regions show higher genetic diversity than those closer to the sea. The genetic differentiation follows a pattern of isolation-by-distance. Landscape features, such as water bodies and wind corridors, and geographical distances equally explain the observed genetic differentiation, whereas the precipitation seasonality exhibits a strong signal for isolation-by-environment in marginal populations. The estimated levels of gene flow suggest that marginal populations had restricted immigration rates enhancing differentiation. CONCLUSIONS: Topographical features related to coastal plain deposition history influence population differentiation in C. heterophylla. Gene flow is mainly restricted to nearby populations and facilitated by wind fields, albeit without any apparent influence of large water bodies. Furthermore, differential rainfall regimes in marginal populations seem to promote genetic differentiation.

Sampling effort and the drivers of plant species richness in the Brazilian coastal regions.

The causes of the gradients in species richness remain contentious because of multiple competing hypotheses, significant knowledge gaps, and regional effects of environmental and historical factors on species pools. Coastal zones are subject to particular sets of environmental constraints, thus identifying the drivers of species richness therein should shed light on the regional gradients of species diversity. Here, we investigate the geographic patterns and drivers of plant diversity across coastal regions while allowing for pervasive sampling deficiencies. Based on 142708 records of flowering plant occurrences, we mapped species richness and estimated the level of knowledge across the coastal zone of Brazil. Based on inventory completeness, we used linear regression models to test the predictive power of environmental variables that represent different environmental hypotheses. Few cells (25%) were well-surveyed, reflecting little knowledge about the distribution and diversity of flowering plants on the highly-populated Brazilian coast. Still, we found support for the habitat heterogeneity hypothesis as the best explanation of the variation in species richness of flowering plants in this region. Soil properties and water constraints are also important factors. Although our work emphasises the paucity of information on plant diversity in tropical and human-dominated areas, we show that knowledge limitations should not curb our capability of addressing hypotheses about species diversity.

A New Species of Mud Turtle of Genus Kinosternon (Testudines: Kinosternidae) from the Pacific Coastal Plain of Northwestern Mexico.

We describe a new species of mud turtle of the genus Kinosternon from the Pacific Coastal Plain of the Mexican states Sinaloa and Nayarit. The new species shares morphological characters with the recently described Kinosternon vogti, which are unique to these two turtles and separate them from the other species of the genus. The new species differs from K. vogti by skin coloration, size, and the scutellation of both carapace and plastron. We also present a molecular phylogeny of the family Kinosternidae based on two mitochondrial and four nuclear loci. Our results show that the new species is most closely related to K. vogti, and together they form the sister group to the K. hirtipes and K. integrum species groups of Kinosternon.

Community structure and species composition of a periodically flooded Restinga forest in Caraguatatuba, São Paulo, Brazil / Estrutura e composição de espécies de uma floresta de Restinga periodicamente alagada em Caraguatatuba, São Paulo, Brasil

Abstract: The aim of this study was to characterize the structure and composition of the tree and shrub community in a 77-ha fragment of Restinga forest in Caraguatatuba, São Paulo, Brazil. In this fragment, forty 20 × 20-m plots (1.6 ha) were systematically allocated and all trees with a stem diameter at breast height (DBH) ≥4.8 cm were sampled. Sixteen plots were randomly chosen to also sample individuals with a DBH of between 1 and 4.8 cm. All individuals were tagged, identified to species level, and their diameters and heights were measured. A total of 2587 individuals (1616 ind./ha) from 119 species and 42 families were found with a DBH >4.8 cm, and 2659 individuals (4154 ind./ha) from 125 species and 38 families were found with a DBH >1 cm. The richest families were Myrtaceae, Lauraceae, and Fabaceae, and the most abundant species were Diospyros brasiliensis (Ebenaceae), Anaxagorea dolichocarpa (Annonaceae), and Euterpe edulis (Arecaceae). The structure of the studied site was similar to that of other Restinga forest sites, but the forest composition was quite distinct. Implications for the conservation and restoration of Restinga forests in this region are discussed in light of the results obtained.

Resumo: O objetivo deste estudo foi caracterizar a estrutura e composição da comunidade arbórea e arbustiva em um fragmento de 77 ha de floresta de Restinga em Caraguatatuba, São Paulo. Neste fragmento, 40 parcelas de 20 × 20 m (1,6 ha) foram distribuídas sistematicamente e todas as árvores com diâmetro do tronco na altura do peito (DAP) ≥4,8 cm foram amostradas. Além disso, 16 parcelas foram escolhidas aleatoriamente para amostrar também todos os indivíduos com DAP entre 1 e 4.8 cm de DAP. Todos os indivíduos foram marcados, identificados ao nível de espécie e tiveram seu diâmetro e altura medidos. Para indivíduos acima de 4,8 cm de DAP, foi amostrado um total de 2587 indivíduos (1616 ind./ha) em 119 espécies e 42 famílias. Para indivíduos acima de 1 cm de DAP, foi amostrado um total de 2659 indivíduos (4154 ind./ha) em 125 espécies e 38 famílias. As famílias mais ricas foram Myrtaceae, Lauraceae e Fabaceae. As espécies mais abundantes foram Diospyros brasiliensis, Anaxagorea dolichocarpa e Euterpe edulis. Quando comparado com outros locais de florestas de Restinga, a estrutura florestal do fragmento estudado é semelhante a outras florestas de Restinga. No entanto, a composição da floresta é bastante distinta, evidenciando a heterogeneidade das florestas de Restinga ao longo da costa do Brasil. Implicações para a conservação e restauração das florestas de Restinga são destacadas.

Paleoenvironmental evolution of the coastal plain of Southern Brazil: palynological data from a Holocene core in Santa Catarina State

ABSTRACT This paper presents a paleoenvironmental reconstruction from palynological analyses of a sedimentary core of Holocene age, drilled at municipality of Garopaba (Santa Catarina), Southern Brazil. A total of 46 samples was collected for palynological analyses in the 450 cm-long core PCSC-3, as also three samples for radiocarbon dating and granulometric analyses. The palynological content includes 84 taxa related to pollen grains of angiosperms (38) and gimnosperm (3), spores of pteridophyta (16) and bryophyta (2), spores of fungi (8), algae (3), acritarchs (3), dinoflagellate cysts (2) and microforaminiferal linings (1). Three specimens of acritarchs are described and illustrated in detail. Three palynological phases were defined based on changes in assemblages: Phase I, Phase II and Phase III. The Phase I is characterized as a lagoonal paleoenvironment with marine influence from the beginning of the sedimentation (5390 cal yr BP), based on occurrences of acritarchs, dinoflagellate cysts and microforaminiferal linings. The Phase II (3032 yr BP until 858 cal yr BP) also is characterized by a lagoonal paleoenvironment, however, presented decrease in percentage of marine elements and increase in freshwater algae record, suggesting less marine influence in the lagoonal body. In Phase III (last 856 years), underwater sedimentation prevailed, under swamp-like conditions.

Responses of water mite assemblages (Acari) to environmental parameters at irrigated rice cultivation fields and native lakes

Many studies have revealed that water mite communities can be affected by the physical and chemical parameters of the water. The similarity between the water ‘mite assemblages in local water bodies and in irrigated rice areas can be a way to measure the water conditions, enabling an assessment of the anthropic impact in the environment. The aim of this study was to evaluate the distribution of water mites in lakes and irrigated rice fields in south Brazil. To accomplish that we characterized the distinctive environments using physical and chemical variables such as pH, turbidity (NTU), water temperature (°C) and dissolved oxygen (mg/L), in order to verify the influence of these abiotic factors on the species composition of water mite communities; and to compare water mite abundance, richness and composition among different habitats. We assessed three native lakes and four sites with irrigated rice cultivation. Our results showed, for the first time in Brazil, strong correlations between the water mite fauna and turbidity. In addition, native lakes were richer and had greater mite abundance when compared with the irrigated rice areas.

Responses of water mite assemblages (Acari) to environmental parameters at irrigated rice cultivation fields and native lakes

Many studies have revealed that water mite communities can be affected by the physical and chemical parameters of the water. The similarity between the water ‘mite assemblages in local water bodies and in irrigated rice areas can be a way to measure the water conditions, enabling an assessment of the anthropic impact in the environment. The aim of this study was to evaluate the distribution of water mites in lakes and irrigated rice fields in south Brazil. To accomplish that we characterized the distinctive environments using physical and chemical variables such as pH, turbidity (NTU), water temperature (°C) and dissolved oxygen (mg/L), in order to verify the influence of these abiotic factors on the species composition of water mite communities; and to compare water mite abundance, richness and composition among different habitats. We assessed three native lakes and four sites with irrigated rice cultivation. Our results showed, for the first time in Brazil, strong correlations between the water mite fauna and turbidity. In addition, native lakes were richer and had greater mite abundance when compared with the irrigated rice areas.(AU)

Two new species of Portanini (Hemiptera: Cicadellidae: Aphrodinae) from Southeastern Brazil.

Two new species, Portanus restingalis and Paraportanus marica, are described and illustrated from Restinga de Maricá, a sandy coastal plain in Rio de Janeiro State, Southeastern Brazil. Comparative notes on the two new species are given. Portanus youngi and Paraportanus eburatus are newly recorded from Brazil and Guyana, respectively. A checklist of all known species of Portanini with their geographic distribution is provided.

Diversidade, biogeografia, caracterização cariotípica e tricológica dos pequenos mamíferos não voadores do Parque Estadual Rio da Onça, Litoral Sul do Paraná

The Atlantic forest possess 1,361 vertebrate species of which 567 are endemic. Rodentia and Didelphimorphia comprise 71% of the endemic mammals observed in this biome. In Brazil, these animals still lack basic information about their biology, distribution, and even total wealth. This study aimed to identify the species of marsupials and rodents present in Rio da Onça State Park and to characterize the morphology of guard hairs and chromosomal set thereof, besides verify the composition of small non-flying mammals in different environments and vegetation strata. Thirteen field campaigns were conducted and as an additional effort, three lines of pitfall traps were installed. The total sampling effort was 6.633 traps and 1.181 buckets spread over 69 nights of sampling, which resulted in 196 captures of 166 individuals of 12 species. Seven species of Rodentia Order were recorded: Akodon montensis, Delomys sublineatus, Euryoryzomys russatus, Juliomys pictipes, Nectomys squamipes, Oligoryzomys nigripes and Thaptomys nigrita and five species of marsupials (Didelphimorphia Order): Didelphis aurita, Gracilinanus microtarsus, Metachirus nudicaudatus, Marmosa paraguayana and Monodelphis iheringi. Trichological and cytogenetic results were consistent with those available in the literature. Regarding the vertical stratification, only seven captures were made in trees. Four of the species Marmosa paraguayana, two Didelphis aurita, and one Akodon montensis. Therefore, in the environment of the lowlands of the study area, sampling carried out on tree and shrub extract of the understory did not contribute to the increase of the species list.

Das 1.361 espécies de vertebrados que a Mata Atlântica abriga, 567 são endêmicas. Rodentia e Didelphimorphia somam 71% dos endemismos observados para mamíferos nesse bioma. No Brasil, esses animais ainda carecem de informações básicas a cerca de sua biologia, distribuição, e mesmo riqueza total. Esse trabalho objetivou identificar as espécies de marsupiais e roedores do Parque Estadual Rio da Onça e caracterizar a morfologia dos pelos-guarda e do conjunto cromossômico das mesmas, além de verificar a composição de pequenos mamíferos não voadores em diferentes ambientes e estratos vegetais. Foram realizadas treze campanhas de campo e como esforço adicional, três linhas de armadilhas de queda foram instaladas. O esforço amostral total foi de 6.633 armadilhas e 1.181 baldes distribuídos ao longo de 69 noites de amostragem, que resultaram em 196 capturas de 166 indivíduos de 12 espécies. Foram registradas sete espécies da Ordem Rodentia: Akodon montensis, Delomys sublineatus, Euryoryzomys russatus, Juliomys pictipes, Nectomys squamipes, Oligoryzomys nigripes e Thaptomys nigrita, além de cinco espécies de marsupiais da Ordem Didelphimorphia: Didelphis aurita, Gracilinanus microtarsus, Metachirus nudicaudatus, Marmosa paraguayana e Monodelphis iheringi. Os resultados tricológicos e citogenéticos foram condizentes com os disponíveis na literatura. Quanto à estratificação vertical, somente sete capturas foram feitas em árvore: quatro da espécie Marmosa paraguayana, duas de Didelphis aurita e uma de Akodon montensis. Portanto, para o ambiente de Terras Baixas da área de estudo, a amostragem realizada no extrato arbóreo e arbustivo do sub-bosque não contribuiu para o incremento da lista de espécies.

Diversidade, biogeografia, caracterização cariotípica e tricológica dos pequenos mamíferos não voadores do parque estadual rio da onça, litoral sul do paraná

ABSTRACT The Atlantic forest possess 1,361 vertebrate species of which 567 are endemic. Rodentia and Didelphimorphia comprise 71% of the endemic mammals observed in this biome. In Brazil, these animals still lack basic information about their biology, distribution, and even total wealth. This study aimed to identify the species of marsupials and rodents present in Rio da Onça State Park and to characterize the morphology of guard hairs and chromosomal set thereof, besides verify the composition of small non-flying mammals in different environments and vegetation strata. Thirteen field campaigns were conducted and as an additional effort, three lines of pitfall traps were installed. The total sampling effort was 6.633 traps and 1.181 buckets spread over 69 nights of sampling, which resulted in 196 captures of 166 individuals of 12 species. Seven species of Rodentia Order were recorded: Akodon montensis, Delomys sublineatus, Euryoryzomys russatus, Juliomys pictipes, Nectomys squamipes, Oligoryzomys nigripes and Thaptomys nigrita and five species of marsupials (Didelphimorphia Order): Didelphis aurita, Gracilinanus microtarsus, Metachirus nudicaudatus, Marmosa paraguayana and Monodelphis iheringi. Trichological and cytogenetic results were consistent with those available in the literature. Regarding the vertical stratification, only seven captures were made in trees. Four of the species Marmosa paraguayana, two Didelphis aurita, and one Akodon montensis. Therefore, in the environment of the lowlands of the study area, sampling carried out on tree and shrub extract of the understory did not contribute to the increase of the species list.

RESUMO Das 1.361 espécies de vertebrados que a Mata Atlântica abriga, 567 são endêmicas. Rodentia e Didelphimorphia somam 71% dos endemismos observados para mamíferos nesse bioma. No Brasil, esses animais ainda carecem de informações básicas a cerca de sua biologia, distribuição, e mesmo riqueza total. Esse trabalho objetivou identificar as espécies de marsupiais e roedores do Parque Estadual Rio da Onça e caracterizar a morfologia dos pelos-guarda e do conjunto cromossômico das mesmas, além de verificar a composição de pequenos mamíferos não voadores em diferentes ambientes e estratos vegetais. Foram realizadas treze campanhas de campo e como esforço adicional, três linhas de armadilhas de queda foram instaladas. O esforço amostral total foi de 6.633 armadilhas e 1.181 baldes distribuídos ao longo de 69 noites de amostragem, que resultaram em 196 capturas de 166 indivíduos de 12 espécies. Foram registradas sete espécies da Ordem Rodentia: Akodon montensis, Delomys sublineatus, Euryoryzomys russatus, Juliomys pictipes, Nectomys squamipes, Oligoryzomys nigripes e Thaptomys nigrita, além de cinco espécies de marsupiais da Ordem Didelphimorphia: Didelphis aurita, Gracilinanus microtarsus, Metachirus nudicaudatus, Marmosa paraguayana e Monodelphis iheringi. Os resultados tricológicos e citogenéticos foram condizentes com os disponíveis na literatura. Quanto à estratificação vertical, somente sete capturas foram feitas em árvore: quatro da espécie Marmosa paraguayana, duas de Didelphis aurita e uma de Akodon montensis. Portanto, para o ambiente de Terras Baixas da área de estudo, a amostragem realizada no extrato arbóreo e arbustivo do sub-bosque não contribuiu para o incremento da lista de espécies.

Diversidade, biogeografia, caracterização cariotípica e tricológica dos pequenos mamíferos não voadores do Parque Estadual Rio da Onça, Litoral Sul do Paraná

The Atlantic forest possess 1,361 vertebrate species of which 567 are endemic. Rodentia and Didelphimorphia comprise 71% of the endemic mammals observed in this biome. In Brazil, these animals still lack basic information about their biology, distribution, and even total wealth. This study aimed to identify the species of marsupials and rodents present in Rio da Onça State Park and to characterize the morphology of guard hairs and chromosomal set thereof, besides verify the composition of small non-flying mammals in different environments and vegetation strata. Thirteen field campaigns were conducted and as an additional effort, three lines of pitfall traps were installed. The total sampling effort was 6.633 traps and 1.181 buckets spread over 69 nights of sampling, which resulted in 196 captures of 166 individuals of 12 species. Seven species of Rodentia Order were recorded: Akodon montensis, Delomys sublineatus, Euryoryzomys russatus, Juliomys pictipes, Nectomys squamipes, Oligoryzomys nigripes and Thaptomys nigrita and five species of marsupials (Didelphimorphia Order): Didelphis aurita, Gracilinanus microtarsus, Metachirus nudicaudatus, Marmosa paraguayana and Monodelphis iheringi. Trichological and cytogenetic results were consistent with those available in the literature. Regarding the vertical stratification, only seven captures were made in trees. Four of the species Marmosa paraguayana, two Didelphis aurita, and one Akodon montensis. Therefore, in the environment of the lowlands of the study area, sampling carried out on tree and shrub extract of the understory did not contribute to the increase of the species list.(AU)

Das 1.361 espécies de vertebrados que a Mata Atlântica abriga, 567 são endêmicas. Rodentia e Didelphimorphia somam 71% dos endemismos observados para mamíferos nesse bioma. No Brasil, esses animais ainda carecem de informações básicas a cerca de sua biologia, distribuição, e mesmo riqueza total. Esse trabalho objetivou identificar as espécies de marsupiais e roedores do Parque Estadual Rio da Onça e caracterizar a morfologia dos pelos-guarda e do conjunto cromossômico das mesmas, além de verificar a composição de pequenos mamíferos não voadores em diferentes ambientes e estratos vegetais. Foram realizadas treze campanhas de campo e como esforço adicional, três linhas de armadilhas de queda foram instaladas. O esforço amostral total foi de 6.633 armadilhas e 1.181 baldes distribuídos ao longo de 69 noites de amostragem, que resultaram em 196 capturas de 166 indivíduos de 12 espécies. Foram registradas sete espécies da Ordem Rodentia: Akodon montensis, Delomys sublineatus, Euryoryzomys russatus, Juliomys pictipes, Nectomys squamipes, Oligoryzomys nigripes e Thaptomys nigrita, além de cinco espécies de marsupiais da Ordem Didelphimorphia: Didelphis aurita, Gracilinanus microtarsus, Metachirus nudicaudatus, Marmosa paraguayana e Monodelphis iheringi. Os resultados tricológicos e citogenéticos foram condizentes com os disponíveis na literatura. Quanto à estratificação vertical, somente sete capturas foram feitas em árvore: quatro da espécie Marmosa paraguayana, duas de Didelphis aurita e uma de Akodon montensis. Portanto, para o ambiente de Terras Baixas da área de estudo, a amostragem realizada no extrato arbóreo e arbustivo do sub-bosque não contribuiu para o incremento da lista de espécies.(AU)

The ichthyofauna of limnic systems in Quaternary deposits of extreme southern Brazil.

The Quaternary in the state of Rio Grande do Sul (RS), southern Brazil, is geologically represented by the coastal plain and was originated by successive events of Pleistocene-Holocene marine transgressions and the occurrence of alluvial deposits. This paper aimed to characterize the fish assemblage occurring in a swampy Quaternary area adjacent to Lagoa Pequena, a lacustrine system connected to the west margin of the Laguna dos Patos estuary. A checklist is also provided of the ichthyofauna so far recorded in limnic systems of Quaternary deposits in the state of Rio Grande do Sul. A total of 42 species was recorded, distributed in nine orders, 18 families and 31 genera. Characidae and Cichlidae were the most representative families, comprising 15 and 4 species respectively. A bibliographic revision associated to our sample data revealed the occurrence of 156 species in limnic systems inserted in RS Quaternary deposits (114 limnic, 15 marine/estuarine/limnic, ten marine/estuarine, nine estuarine/limnic and eight marine). Characiformes and Siluriformes are the most diverse orders, corroborating the Neotropical pattern. Seven species can be considered endemic to RS Quaternary deposits.

DIVERSIDADE, BIOGEOGRAFIA, CARACTERIZAÇÃO CARIOTÍPICA E TRICOLÓGICA DOS PEQUENOS MAMÍFEROS NÃO VOADORES DO PARQUE ESTADUAL RIO DA ONÇA, LITORAL SUL DO PARANÁ

ABSTRACT The Atlantic forest possess 1,361 vertebrate species of which 567 are endemic. Rodentia and Didelphimorphia comprise 71% of the endemic mammals observed in this biome. In Brazil, these animals still lack basic information about their biology, distribution, and even total wealth. This study aimed to identify the species of marsupials and rodents present in Rio da Onça State Park and to characterize the morphology of guard hairs and chromosomal set thereof, besides verify the composition of small non-flying mammals in different environments and vegetation strata. Thirteen field campaigns were conducted and as an additional effort, three lines of pitfall traps were installed. The total sampling effort was 6.633 traps and 1.181 buckets spread over 69 nights of sampling, which resulted in 196 captures of 166 individuals of 12 species. Seven species of Rodentia Order were recorded: Akodon montensis, Delomys sublineatus, Euryoryzomys russatus, Juliomys pictipes, Nectomys squamipes, Oligoryzomys nigripes and Thaptomys nigrita and five species of marsupials (Didelphimorphia Order): Didelphis aurita, Gracilinanus microtarsus, Metachirus nudicaudatus, Marmosa paraguayana and Monodelphis iheringi. Trichological and cytogenetic results were consistent with those available in the literature. Regarding the vertical stratification, only seven captures were made in trees. Four of the species Marmosa paraguayana, two Didelphis aurita, and one Akodon montensis. Therefore, in the environment of the lowlands of the study area, sampling carried out on tree and shrub extract of the understory did not contribute to the increase of the species list.

RESUMO Das 1.361 espécies de vertebrados que a Mata Atlântica abriga, 567 são endêmicas. Rodentia e Didelphimorphia somam 71% dos endemismos observados para mamíferos nesse bioma. No Brasil, esses animais ainda carecem de informações básicas a cerca de sua biologia, distribuição, e mesmo riqueza total. Esse trabalho objetivou identificar as espécies de marsupiais e roedores do Parque Estadual Rio da Onça e caracterizar a morfologia dos pelos-guarda e do conjunto cromossômico das mesmas, além de verificar a composição de pequenos mamíferos não voadores em diferentes ambientes e estratos vegetais. Foram realizadas treze campanhas de campo e como esforço adicional, três linhas de armadilhas de queda foram instaladas. O esforço amostral total foi de 6.633 armadilhas e 1.181 baldes distribuídos ao longo de 69 noites de amostragem, que resultaram em 196 capturas de 166 indivíduos de 12 espécies. Foram registradas sete espécies da Ordem Rodentia: Akodon montensis, Delomys sublineatus, Euryoryzomys russatus, Juliomys pictipes, Nectomys squamipes, Oligoryzomys nigripes e Thaptomys nigrita, além de cinco espécies de marsupiais da Ordem Didelphimorphia: Didelphis aurita, Gracilinanus microtarsus, Metachirus nudicaudatus, Marmosa paraguayana e Monodelphis iheringi. Os resultados tricológicos e citogenéticos foram condizentes com os disponíveis na literatura. Quanto à estratificação vertical, somente sete capturas foram feitas em árvore: quatro da espécie Marmosa paraguayana, duas de Didelphis aurita e uma de Akodon montensis. Portanto, para o ambiente de Terras Baixas da área de estudo, a amostragem realizada no extrato arbóreo e arbustivo do sub-bosque não contribuiu para o incremento da lista de espécies.

Mangrove sedimentary characteristics and implications for crab Ucides cordatus (Crustacea, Decapoda, Ucididae) distribution in an estuarine area of the Amazonian region / Características sedimentares de manguezal e implicações para a distribuição do caranguejo-uçá Ucides cordatus (Crustacea, Decapoda, Ucididae) em uma área estuarina amazônica

At the coastal zone sediments, water and organisms interact intensely. At equatorial tidal-dominated coast mangroves are abundant. These areas are well-known for their ecological importance. Considering the mangroves of Atlantic South America, the mangrove crab, Ucides cordatus has ecological and economic prominence. High densities of this crab are found on the Amazon coast. This study investigates the sediment distribution of the Bragança mangrove area (Amazon coast, Brazil) and its correlations with vegetation and mangrove crab distribution. Sediments of 47 sites, as well as crabs from sites with different sediment and vegetation, were sampled. Results show that surface sediment of the area is mainly composed by silt (59%), with 21% sand and 20% clay. Variations in sorting and skewness are the product of local variations in clay and sand content. The vegetation type was significantly correlated to mangrove crab characteristics, abundance and weight/size. Sediment characteristics are also substantially different according to the vegetation type. Areas where Avicennia germinans prevails have more sand and clay than areas of Rizophora mangle, in which silt is dominant and crabs were significantly heavier. The present results have showed that the distribution of sediments, crabs and vegetation at mangrove areas are strongly correlated. Thus, they should be studied in conjunction.

Na zona costeira, sedimentos, água e organismos interagem intensamente. Nas costas equatoriais dominadas por maré os manguezais são abundantes. Estas áreas são conhecidas por sua importância ecológica. No caso dos manguezais da costa atlântica da América do Sul o caranguejo-uçá Ucides cordatus (Linnaeus, 1763) se destaca por sua relevância ecológica e econômica, sendo que altas densidades deste organismo são encontradas na zona costeira amazônica. O presente estudo investiga a distribuição de sedimentos nos manguezais de Bragança (costa Amazônica, Brasil) e suas correlações com a vegetação e a distribuição do caranguejo-uçá. Quarenta e sete amostras de sedimento foram avaliadas, assim como caranguejos de 8 destas áreas foram coletados, onde o tipo dominante de vegetação foi também identificado. Os resultados demonstram que os sedimentos superficiais, assim como no extrato 0,8 a 1 m de profundidade, na área são principalmente compostos por silte (59%), incluindo em média 21% de areia e 20% de argila. O tipo de vegetação predominante foi significativamente correlacionado com a abundância e tamanho/peso dos caranguejos. As características sedimentares também foram substancialmente diferentes dependendo da vegetação. Áreas dominadas por Avicennia germinans tiveram mais areia e argila que as áreas dominadas por Rizophora mangle, onde a fração silte prevalece grandemente e os caranguejos eram significativamente maiores e mais abundantes. Os resultados demonstraram que sedimentos, invertebrados bentônicos e vegetação estão intimamente relacionados nos manguezais e devem ser estudados de maneira integrada.

Dieta e estratégia alimentar de Characidium rachovii (Characiformes, Crenuchidae) em riachos de planície costeira do sul do Brasil / Diet and feeding strategy of Characidium rachovii (Characiformes, Crenuchidae) in coastal plain streams of southern Brazil

Characidium rachovii (Regan, 1913) is a frequent species in coastal plain streams on state of Rio Grande do Sul, southern Brazil. However, its trophic niche is still unknown. This paper aimed to: (i) describe the diet of C. rachovii in three coastal plain streams of RS; (ii) evaluate the influence of an ecotone (sea-stream) in the diet by comparing two sites, one near and other distant of the sea, and (iii) evaluate the effect of individuals number analyzed on the richness of the diet. The stomach contents analysis of 139 individuals revealed that the species was a specialist in Diptera (aquatic stage) and Amphipoda. Characidium rachovii was also opportunist, since besides such preference, consumed great richness of resources (24 items) and various with low frequency and high abundance. There were no differences in diet composition among streams and sites. The expected richness (rarefaction) showed that the number of individuals analyzed changes the estimate of diet richness in species that consume several items at low frequency.

Characidium rachovii (Regan, 1913) é uma espécie frequente em riachos da planície costeira do estado do Rio Grande do Sul, sul do Brasil. Entretanto, seu nicho trófico é ainda desconhecido. O presente trabalho teve como objetivos: (i) descrever a dieta de C. rachovii de três riachos costeiros do RS; (ii) avaliar a influência de um ecótono (mar-riacho) na dieta, comparando dois locais, um próximo do mar e outro distante, e (iii) avaliar o efeito do número de indivíduos analisados na riqueza da dieta. A análise do conteúdo estomacal de 139 indivíduos revelou que a espécie é especializada no consumo de Diptera (estágio aquático) e Amphipoda. Ao mesmo tempo, pode-se considerar que C. rachovii apresentou hábito alimentar oportunista, já que, apesar de tal preferência, consumiu grande riqueza de recursos (24 itens), vários deles em baixa frequência e alta abundância. Não houve diferenças na composição da dieta entre os riachos e locais. A riqueza esperada (rarefação) mostrou que o número de indivíduos analisados altera a estimativa de riqueza da dieta em espécies que consomem itens raros.

Mangrove sedimentary characteristics and implications for crab Ucides cordatus (Crustacea, Decapoda, Ucididae) distribution in an estuarine area of the Amazonian region / Características sedimentares de manguezal e implicações para a distribuição do caranguejo-uçá Ucides cordatus (Crustacea, Decapoda, Ucididae) em uma área estuarina amazônica

At the coastal zone sediments, water and organisms interact intensely. At equatorial tidal-dominated coast mangroves are abundant. These areas are well-known for their ecological importance. Considering the mangroves of Atlantic South America, the mangrove crab, Ucides cordatus has ecological and economic prominence. High densities of this crab are found on the Amazon coast. This study investigates the sediment distribution of the Bragança mangrove area (Amazon coast, Brazil) and its correlations with vegetation and mangrove crab distribution. Sediments of 47 sites, as well as crabs from sites with different sediment and vegetation, were sampled. Results show that surface sediment of the area is mainly composed by silt (59%), with 21% sand and 20% clay. Variations in sorting and skewness are the product of local variations in clay and sand content. The vegetation type was significantly correlated to mangrove crab characteristics, abundance and weight/size. Sediment characteristics are also substantially different according to the vegetation type. Areas where Avicennia germinans prevails have more sand and clay than areas of Rizophora mangle, in which silt is dominant and crabs were significantly heavier. The present results have showed that the distribution of sediments, crabs and vegetation at mangrove areas are strongly correlated. Thus, they should be studied in conjunction.(AU)

Na zona costeira, sedimentos, água e organismos interagem intensamente. Nas costas equatoriais dominadas por maré os manguezais são abundantes. Estas áreas são conhecidas por sua importância ecológica. No caso dos manguezais da costa atlântica da América do Sul o caranguejo-uçá Ucides cordatus (Linnaeus, 1763) se destaca por sua relevância ecológica e econômica, sendo que altas densidades deste organismo são encontradas na zona costeira amazônica. O presente estudo investiga a distribuição de sedimentos nos manguezais de Bragança (costa Amazônica, Brasil) e suas correlações com a vegetação e a distribuição do caranguejo-uçá. Quarenta e sete amostras de sedimento foram avaliadas, assim como caranguejos de 8 destas áreas foram coletados, onde o tipo dominante de vegetação foi também identificado. Os resultados demonstram que os sedimentos superficiais, assim como no extrato 0,8 a 1 m de profundidade, na área são principalmente compostos por silte (59%), incluindo em média 21% de areia e 20% de argila. O tipo de vegetação predominante foi significativamente correlacionado com a abundância e tamanho/peso dos caranguejos. As características sedimentares também foram substancialmente diferentes dependendo da vegetação. Áreas dominadas por Avicennia germinans tiveram mais areia e argila que as áreas dominadas por Rizophora mangle, onde a fração silte prevalece grandemente e os caranguejos eram significativamente maiores e mais abundantes. Os resultados demonstraram que sedimentos, invertebrados bentônicos e vegetação estão intimamente relacionados nos manguezais e devem ser estudados de maneira integrada.(AU)

Dieta e estratégia alimentar de Characidium rachovii (Characiformes, Crenuchidae) em riachos de planície costeira do sul do Brasil / Diet and feeding strategy of Characidium rachovii (Characiformes, Crenuchidae) in coastal plain streams of southern Brazil

Characidium rachovii (Regan, 1913) is a frequent species in coastal plain streams on state of Rio Grande do Sul, southern Brazil. However, its trophic niche is still unknown. This paper aimed to: (i) describe the diet of C. rachovii in three coastal plain streams of RS; (ii) evaluate the influence of an ecotone (sea-stream) in the diet by comparing two sites, one near and other distant of the sea, and (iii) evaluate the effect of individuals number analyzed on the richness of the diet. The stomach contents analysis of 139 individuals revealed that the species was a specialist in Diptera (aquatic stage) and Amphipoda. Characidium rachovii was also opportunist, since besides such preference, consumed great richness of resources (24 items) and various with low frequency and high abundance. There were no differences in diet composition among streams and sites. The expected richness (rarefaction) showed that the number of individuals analyzed changes the estimate of diet richness in species that consume several items at low frequency.(AU)

Characidium rachovii (Regan, 1913) é uma espécie frequente em riachos da planície costeira do estado do Rio Grande do Sul, sul do Brasil. Entretanto, seu nicho trófico é ainda desconhecido. O presente trabalho teve como objetivos: (i) descrever a dieta de C. rachovii de três riachos costeiros do RS; (ii) avaliar a influência de um ecótono (mar-riacho) na dieta, comparando dois locais, um próximo do mar e outro distante, e (iii) avaliar o efeito do número de indivíduos analisados na riqueza da dieta. A análise do conteúdo estomacal de 139 indivíduos revelou que a espécie é especializada no consumo de Diptera (estágio aquático) e Amphipoda. Ao mesmo tempo, pode-se considerar que C. rachovii apresentou hábito alimentar oportunista, já que, apesar de tal preferência, consumiu grande riqueza de recursos (24 itens), vários deles em baixa frequência e alta abundância. Não houve diferenças na composição da dieta entre os riachos e locais. A riqueza esperada (rarefação) mostrou que o número de indivíduos analisados altera a estimativa de riqueza da dieta em espécies que consomem itens raros.(AU)

The activity patterns and microhabitat use of Pseudis minuta Günther, 1858 (Anura, Hylidae) in the Lagoa do Peixe National Park, a biosphere reserve of the brazilian subtropics / Padrão de atividade e uso de micro-habitat de Pseudis minuta Günther, 1858 (Anura, Hylidae) no Parque Nacional da Lagoa do Peixe, uma reserva da biosfera na região subtropical do Brasil

Pseudis minuta is abundant in a variety of aquatic environments of the Pampa domain. Therefore, it can be considered a good model for testing hypotheses on environmental heterogeneity and the influence of climate on the activity of anurans. In this study, we examined the spatial distribution pattern of P. minuta in terms of microhabitats and the influence of abiotic factors on seasonal fluctuations in the abundance of this species. Samples were collected monthly from April 2008 to May 2009 in wetlands and coastal dunes in the Lagoa do Peixe National Park. A total of 112 specimens of P. minuta were collected, of which 45 were found in the wetland area and 67 in the dune area. The species showed seasonal fluctuation in abundance, and it was most abundant in months with higher temperatures (spring-summer). Pseudis minuta was mainly associated with aquatic vegetation, an expected pattern in terms of their morphological adaptations to this environment. Among the abiotic parameters analyzed, only the monthly mean temperature showed a significant correlation (p < 0.05; r = 0.67) with the abundance of P. minuta. We concluded that P. minuta is a generalist species with respect to microhabitat use and also that fluctuation in its population abundance is mainly associated with seasonal variation in temperature.

Pseudis minuta é uma espécie abundante em diferentes tipos de ambientes aquáticos do domínio Pampa. Por essa razão, essa espécie pode ser considerada um bom modelo para testar hipóteses relacionadas à heterogeneidade ambiental e à influência do clima sobre padrões de atividade em anuros. Neste trabalho, foi avaliado o padrão de distribuição espacial de P. minuta em termos de micro-habitats, além de se avaliar a influência de fatores abióticos nas flutuações sazonais da abundância dessa espécie. Coletas foram realizadas mensalmente, entre abril de 2008 e maio de 2009, em áreas úmidas e de cordões de dunas costeiras no Parque Nacional de Lagoa do Peixe. Um total de 112 indivíduos de P. minuta foi coletado, sendo 45 em áreas de banhado e 67 em área de dunas. A espécie apresentou flutuação sazonal na abundância, sendo mais abundantes em meses com temperaturas mais elevadas (primavera-verão). Pseudis minuta esteve associada principalmente à vegetação aquática, um padrão esperado em função de suas adaptações morfológicas a esse meio. Entre os parâmetros abióticos analisados, somente a temperatura média mensal apresentou correlação significativa (p < 0.05; r = 0,67) com a abundância de P. minuta. Foi possível concluir que P. minuta é uma espécie generalista com relação ao uso do habitat e que as flutuações na sua abundância populacional estão principalmente associadas à variação sazonal da temperatura.

The activity patterns and microhabitat use of Pseudis minuta Günther, 1858 (Anura, Hylidae) in the Lagoa do Peixe National Park, a biosphere reserve of the brazilian subtropics

Pseudis minuta is abundant in a variety of aquatic environments of the Pampa domain. Therefore, it can be considered a good model for testing hypotheses on environmental heterogeneity and the influence of climate on the activity of anurans. In this study, we examined the spatial distribution pattern of P. minuta in terms of microhabitats and the influence of abiotic factors on seasonal fluctuations in the abundance of this species. Samples were collected monthly from April 2008 to May 2009 in wetlands and coastal dunes in the Lagoa do Peixe National Park. A total of 112 specimens of P. minuta were collected, of which 45 were found in the wetland area and 67 in the dune area. The species showed seasonal fluctuation in abundance, and it was most abundant in months with higher temperatures (spring-summer). Pseudis minuta was mainly associated with aquatic vegetation, an expected pattern in terms of their morphological adaptations to this environment. Among the abiotic parameters analyzed, only the monthly mean temperature showed a significant correlation (p 0.05; r = 0.67) with the abundance of P. minuta. We concluded that P. minuta is a generalist species with respect to microhabitat use and also that fluctuation in its population abundance is mainly associated with seasonal variation in temperature.

Pseudis minuta é uma espécie abundante em diferentes tipos de ambientes aquáticos do domínio Pampa. Por essa razão, essa espécie pode ser considerada um bom modelo para testar hipóteses relacionadas à heterogeneidade ambiental e à influência do clima sobre padrões de atividade em anuros. Neste trabalho, foi avaliado o padrão de distribuição espacial de P. minuta em termos de micro-habitats, além de se avaliar a influência de fatores abióticos nas flutuações sazonais da abundância dessa espécie. Coletas foram realizadas mensalmente, entre abril de 2008 e maio de 2009, em áreas úmidas e de cordões de dunas costeiras no Parque Nacional de Lagoa do Peixe. Um total de 112 indivíduos de P. minuta foi coletado, sendo 45 em áreas de banhado e 67 em área de dunas. A espécie apresentou flutuação sazonal na abundância, sendo mais abundantes em meses com temperaturas mais elevadas (primavera-verão). Pseudis minuta esteve associada principalmente à vegetação aquática, um padrão esperado em função de suas adaptações morfológicas a esse meio. Entre os parâmetros abióticos analisados, somente a temperatura média mensal apresentou correlação significativa (p 0.05; r = 0,67) com a abundância de P. minuta. Foi possível concluir que P. minuta é uma espécie generalista com relação ao uso do habitat e que as flutuações na sua abundância populacional estão principalmente associadas à variação sazonal da temperatura.