First record of Plectris aliena Chapin, 1934 (Coleoptera: Melolonthidae) as a potential sugarcane pest in Brazil

Plectris aliena Chapin, 1934, a white grub that promotes serious damage to a variety of crops in North America and Australia, has been reported for the first time in Brazil. Larvae and adults of P. aliena were recorded in sugarcane crops in the state of Mato Grosso do Sul, sampled by trenches in the soil with light traps, respectively, during 2012 and 2013. Root consumption was also determined for the first, second and third instar larvae. The species is univoltine; adults were found mainly in Aug and the peak of third instar larval density was in Apr in all fields sampled. Pupae and adults of P. aliena were observed in the soil profile at depths of up to 60 and 80 cm, respectively. Larvae of P. aliena of the second and third instar consumed the primary and secondary roots of sugarcane, causing serious damage. Third instar larvae consumed 916 mg of root fresh matter, representing 72 % of the sugarcane root system. These results assist in furthering the understanding of its larval dynamics in the soil and provide support for Integrated Pest Management.

First record of Plectris aliena Chapin, 1934 (Coleoptera: Melolonthidae) as a potential sugarcane pest in Brazil

Plectris alienaChapin, 1934, a white grub that promotes serious damage to a variety of crops in North America and Australia, has been reported for the first time in Brazil. Larvae and adults of P. aliena were recorded in sugarcane crops in the state of Mato Grosso do Sul, sampled by trenches in the soil with light traps, respectively, during 2012 and 2013. Root consumption was also determined for the first, second and third instar larvae. The species is univoltine; adults were found mainly in Aug and the peak of third instar larval density was in Apr in all fields sampled. Pupae and adults of P. aliena were observed in the soil profile at depths of up to 60 and 80 cm, respectively. Larvae of P. aliena of the second and third instar consumed the primary and secondary roots of sugarcane, causing serious damage. Third instar larvae consumed 916 mg of root fresh matter, representing 72 % of the sugarcane root system. These results assist in furthering the understanding of its larval dynamics in the soil and provide support for Integrated Pest Management.

First record of Plectris aliena Chapin, 1934 (Coleoptera: Melolonthidae) as a potential sugarcane pest in Brazil

ABSTRACT: Plectris alienaChapin, 1934, a white grub that promotes serious damage to a variety of crops in North America and Australia, has been reported for the first time in Brazil. Larvae and adults of P. aliena were recorded in sugarcane crops in the state of Mato Grosso do Sul, sampled by trenches in the soil with light traps, respectively, during 2012 and 2013. Root consumption was also determined for the first, second and third instar larvae. The species is univoltine; adults were found mainly in Aug and the peak of third instar larval density was in Apr in all fields sampled. Pupae and adults of P. aliena were observed in the soil profile at depths of up to 60 and 80 cm, respectively. Larvae of P. aliena of the second and third instar consumed the primary and secondary roots of sugarcane, causing serious damage. Third instar larvae consumed 916 mg of root fresh matter, representing 72 % of the sugarcane root system. These results assist in furthering the understanding of its larval dynamics in the soil and provide support for Integrated Pest Management.

Variation in dung beetle (Coleoptera: Scarabaeidae: Scarabaeinae) assemblages in a tropical forest remnant from a Mexican National Park

Abstract The Cañón del Sumidero National Park (PNCS) is a priority area for conservation, but there are few studies on its fauna, which evidences the need for further basic studies to produce adequate knowledge on its biodiversity. This study aimed to determine dung beetle assemblages temporal distribution, trophic preference, and daily activity patterns. We conducted samplings using baited pitfall traps in a PNCS tropical sub deciduous forest remnant, during the dry and rainy seasons between 2014 and 2015. We captured a total of 863 individuals of 20 species, 12 genera, and five tribes of Scarabaeinae. Estimators suggest that we obtained high faunistic representation (> 80%), but species richness is low compared to other regional studies. The community was characterized by a high number of rare species and few dominant species. We captured the greatest richness and abundance during rainy months, however, species composition between seasons did not differ significantly. Trophic preference was mainly generalist and we considered only four species as specialists to tapir dung. We observed a clear segregation between activity hours. Nevertheless, we determined only nine species as specialists (six nocturnal and three diurnal) and two others had generalist habits. The low diversity we found could be influenced by the constant pressure of the urban area and non-native species within the park, which alter the dung beetle assemblages. However, performing samplings for longer periods and using a wider range of resources would help us obtain more robust results and better understand species distribution patterns.

Variation in dung beetle (Coleoptera: Scarabaeidae: Scarabaeinae) assemblages in a tropical forest remnant from a Mexican National Park

Abstract The Cañón del Sumidero National Park (PNCS) is a priority area for conservation, but there are few studies on its fauna, which evidences the need for further basic studies to produce adequate knowledge on its biodiversity. This study aimed to determine dung beetle assemblages temporal distribution, trophic preference, and daily activity patterns. We conducted samplings using baited pitfall traps in a PNCS tropical sub deciduous forest remnant, during the dry and rainy seasons between 2014 and 2015. We captured a total of 863 individuals of 20 species, 12 genera, and five tribes of Scarabaeinae. Estimators suggest that we obtained high faunistic representation (> 80%), but species richness is low compared to other regional studies. The community was characterized by a high number of rare species and few dominant species. We captured the greatest richness and abundance during rainy months, however, species composition between seasons did not differ significantly. Trophic preference was mainly generalist and we considered only four species as specialists to tapir dung. We observed a clear segregation between activity hours. Nevertheless, we determined only nine species as specialists (six nocturnal and three diurnal) and two others had generalist habits. The low diversity we found could be influenced by the constant pressure of the urban area and non-native species within the park, which alter the dung beetle assemblages. However, performing samplings for longer periods and using a wider range of resources would help us obtain more robust results and better understand species distribution patterns.

Variation in dung beetle (Coleoptera: Scarabaeidae: Scarabaeinae) assemblages in a tropical forest remnant from a Mexican National Park

The Cañón del Sumidero National Park (PNCS) is a priority area for conservation, but there are few studies on its fauna, which evidences the need for further basic studies to produce adequate knowledge on its biodiversity. This study aimed to determine dung beetle assemblages temporal distribution, trophic preference, and daily activity patterns. We conducted samplings using baited pitfall traps in a PNCS tropical sub deciduous forest remnant, during the dry and rainy seasons between 2014 and 2015. We captured a total of 863 individuals of 20 species, 12 genera, and five tribes of Scarabaeinae. Estimators suggest that we obtained high faunistic representation (> 80%), but species richness is low compared to other regional studies. The community was characterized by a high number of rare species and few dominant species. We captured the greatest richness and abundance during rainy months, however, species composition between seasons did not differ significantly. Trophic preference was mainly generalist and we considered only four species as specialists to tapir dung. We observed a clear segregation between activity hours. Nevertheless, we determined only nine species as specialists (six nocturnal and three diurnal) and two others had generalist habits. The low diversity we found could be influenced by the constant pressure of the urban area and non-native species within the park, which alter the dung beetle assemblages. However, performing samplings for longer periods and using a wider range of resources would help us obtain more robust results and better understand species distribution patterns.(AU)

Polyplacophora (Mollusca) from reef ecosystems and associations with macroalgae on the Coast of Alagoas, Northeastern Brazil

Brazilian marine molluscs, especially Gastropoda and Bivalvia, are relatively well studied. However, information on the class Polyplacophora is more scarce, particularly on reef-dwelling forms. This study aimed to qualitatively and quantitatively analyze aspects of polyplacophorans from reef ecosystems and their associations with macroalgae on the coast of Maceió (state of Alagoas, Brazilian Northeast). The study area included five coral reefs at Ipioca, Ponta do Prego, Ponta do Meirim, Riacho Doce and Ponta Verde, as well as two sandstone reefs, located in Guaxuma and Sereia. The samples were obtained by snorkelling along the intertidal and subtidal reef zones to a depth of up to five meters during low tides, between 2009 and 2011. In addition, the chitons associated with three macroalgae of the Ponta Verde coral reef were studied based on collections made over 12 years (from the summer of 1998 to the winter of 2009). Three replicates with an area of 25 cm2 were collected from each of the following species of macroalgal phytals: Amphiroa fragilissima (Rhodophyta), Caulerpa racemosa (Chlorophyta) and Dictyota cervicornis (Phaeophyta). A total of 715 individuals (110 juveniles and 605 adults) were identified, including Acanthochitona terezae Guerra, 1983, Ischnochiton striolatus (Gray, 1828) and Ischnoplax pectinata (Sowerby II, 1840). Acanthochitona terezae was found for the first time in the area. Ischnochiton striolatus was the most abundant species in the reef ecosystem and in association with macroalgae. The greatest number of individuals of all three polyplacophorans identified (adults and juveniles) was found on the phytal A. fragilissima.

Polyplacophora (Mollusca) from reef ecosystems and associations with macroalgae on the Coast of Alagoas, Northeastern Brazil

Brazilian marine molluscs, especially Gastropoda and Bivalvia, are relatively well studied. However, information on the class Polyplacophora is more scarce, particularly on reef-dwelling forms. This study aimed to qualitatively and quantitatively analyze aspects of polyplacophorans from reef ecosystems and their associations with macroalgae on the coast of Maceió (state of Alagoas, Brazilian Northeast). The study area included five coral reefs at Ipioca, Ponta do Prego, Ponta do Meirim, Riacho Doce and Ponta Verde, as well as two sandstone reefs, located in Guaxuma and Sereia. The samples were obtained by snorkelling along the intertidal and subtidal reef zones to a depth of up to five meters during low tides, between 2009 and 2011. In addition, the chitons associated with three macroalgae of the Ponta Verde coral reef were studied based on collections made over 12 years (from the summer of 1998 to the winter of 2009). Three replicates with an area of 25 cm2 were collected from each of the following species of macroalgal phytals: Amphiroa fragilissima (Rhodophyta), Caulerpa racemosa (Chlorophyta) and Dictyota cervicornis (Phaeophyta). A total of 715 individuals (110 juveniles and 605 adults) were identified, including Acanthochitona terezae Guerra, 1983, Ischnochiton striolatus (Gray, 1828) and Ischnoplax pectinata (Sowerby II, 1840). Acanthochitona terezae was found for the first time in the area. Ischnochiton striolatus was the most abundant species in the reef ecosystem and in association with macroalgae. The greatest number of individuals of all three polyplacophorans identified (adults and juveniles) was found on the phytal A. fragilissima.(AU)

Variação temporal de cladóceros marinhos em uma região estuarina de Ubatuba, SP, Brasil / Temporal variation of marine cladocerans in an estuarine region of Ubatuba, SP, Brazil

The influence of temperature, salinity, pH and dissolved oxygen on the temporal distribution of marine cladocerans at Escuro River estuary, Municipality of Ubatuba, SP, was analysed. Sampling nearest to the surf zone was carried out from July 2004 to June 2005. The cladoceran Penilia avirostris (Dana, 1852) was the dominant species and appeared throughout the sampled period. The species Pseudevadne tergestina (Claus, 1877) and Pleopis polyphemoides (Leuckart, 1859) were the less frequent and Pleopis polyphemoides has occurred mainly in the winter. A negative relationship was obtained for P. avirostris abundance and the water dissolved oxygen, probably as an indirect effect to the water turbulence. Pleopis polyphemoides had a negative relationship with the water temperature and positive with salinity and pH. Abundance of P. tergestina was associated only with salinity. Our findings suggest that P. avirostris is the most resistant species to the local environmental oscillations and that the main factor avoiding their entrance into the estuary is the water turbulence near to the surf zone. Largest abundances of P. tergestina and P. polyphemoides are depending on higher salinity and, low temperatures are good indicators of occurrence of P. polyphemoides.(AU)

A influência da temperatura, salinidade, pH e oxigênio dissolvido na distribuição temporal dos cladóceros marinhos foram analisados na foz do estuário do Rio Escuro, em Ubatuba, SP. Amostragens próximas à zona de arrebentação foram realizadas no período de junho de 2004 a julho de 2005. O cladócero Penilia avirostris (Dana, 1852) foi a espécie dominante e ocorreu ao longo de todo período amostral. As espécies Pseudevadne tergestina (Claus, 1877) e Pleopis polyphemoides (Leuckart, 1859) foram as menos frequentes, esta última com ocorrência principalmente no inverno. A espécie P. avirostris apresentou correlação negativa com o oxigênio dissolvido, provavelmente uma resposta indireta à turbulência da água no local de estudo. Pleopis polyphemoides apresentou correlação negativa com a temperatura da água e positiva com a salinidade e o pH. Pseudevadne tergestina esteve associada apenas a altas salinidades. Os resultados indicam que, dentre as espécies amostradas, P. avirostris é a mais tolerante às oscilações das variáveis ambientais locais, e que o principal fator limitante à sua entrada no estuário é a turbulência das águas próximas à zona de arrebentação. Maiores abundâncias de P. tergestina e P. polyphemoides dependem de salinidades mais elevadas no estuário, e baixas temperaturas são bons indicadores da ocorrência de P. polyphemoides.(AU)

Variação temporal de cladóceros marinhos em uma região estuarina de Ubatuba, SP, Brasil / Temporal variation of marine cladocerans in an estuarine region of Ubatuba, SP, Brazil

The influence of temperature, salinity, pH and dissolved oxygen on the temporal distribution of marine cladocerans at Escuro River estuary, Municipality of Ubatuba, SP, was analysed. Sampling nearest to the surf zone was carried out from July 2004 to June 2005. The cladoceran Penilia avirostris (Dana, 1852) was the dominant species and appeared throughout the sampled period. The species Pseudevadne tergestina (Claus, 1877) and Pleopis polyphemoides (Leuckart, 1859) were the less frequent and Pleopis polyphemoides has occurred mainly in the winter. A negative relationship was obtained for P. avirostris abundance and the water dissolved oxygen, probably as an indirect effect to the water turbulence. Pleopis polyphemoides had a negative relationship with the water temperature and positive with salinity and pH. Abundance of P. tergestina was associated only with salinity. Our findings suggest that P. avirostris is the most resistant species to the local environmental oscillations and that the main factor avoiding their entrance into the estuary is the water turbulence near to the surf zone. Largest abundances of P. tergestina and P. polyphemoides are depending on higher salinity and, low temperatures are good indicators of occurrence of P. polyphemoides.

A influência da temperatura, salinidade, pH e oxigênio dissolvido na distribuição temporal dos cladóceros marinhos foram analisados na foz do estuário do Rio Escuro, em Ubatuba, SP. Amostragens próximas à zona de arrebentação foram realizadas no período de junho de 2004 a julho de 2005. O cladócero Penilia avirostris (Dana, 1852) foi a espécie dominante e ocorreu ao longo de todo período amostral. As espécies Pseudevadne tergestina (Claus, 1877) e Pleopis polyphemoides (Leuckart, 1859) foram as menos frequentes, esta última com ocorrência principalmente no inverno. A espécie P. avirostris apresentou correlação negativa com o oxigênio dissolvido, provavelmente uma resposta indireta à turbulência da água no local de estudo. Pleopis polyphemoides apresentou correlação negativa com a temperatura da água e positiva com a salinidade e o pH. Pseudevadne tergestina esteve associada apenas a altas salinidades. Os resultados indicam que, dentre as espécies amostradas, P. avirostris é a mais tolerante às oscilações das variáveis ambientais locais, e que o principal fator limitante à sua entrada no estuário é a turbulência das águas próximas à zona de arrebentação. Maiores abundâncias de P. tergestina e P. polyphemoides dependem de salinidades mais elevadas no estuário, e baixas temperaturas são bons indicadores da ocorrência de P. polyphemoides.

Comparação de três redes para identificar a estrutura de assembléias de peixes em praias estuarinas de São Francisco do Sul, Santa Catarina / Comparison between three nets to identify the structure of fish assemblagesin estuarine beaches of São Francisco do Sul, Santa Catarina

The catchability of three type seine nets was compared in seven estuarine beaches of Sao Francisco do Sul, Santa Catarina. The capture of specimens and taxa was higher in the net 2.5 mm mesh with nets of meshes 1 and 2.5 mm showing a higher number of unique species. In general terms it was noted that the nets of meshes 1 and 2.5mm capture a greater number of specimens of smaller size. In most months the average collection for net and the number of fish species, Shannon-Wiener and equitability not differ significantly. Considering the beaches separately, between the nets used in the collections were not significant differences between the mean number of specimens and equitability, with differences in the average number of fish and Shannon-Wiener. Through cluster analysis shows that nets of meshes of 2.5 and 5.0 mm shown in estuarine beaches studied in assemblies similar pattern of temporal variation, differing markedly from the temporal pattern identified with the net of mesh 1mm. In spatial terms the three nets showed different results, with a greater similarity between the assemblages sampled by nets of 2.5 and 5mm.(AU)

A capturabilidade de três redes tipo picaré foi comparada em sete praias estuarinas de São Francisco do Sul, Santa Catarina. A captura de exemplares e taxa foi maior na rede de malha de 2,5 mm, com as redes de malhas de 1 e 2,5 mm apresentando um maior número de espécies exclusivas. Em termos gerais observou-se que as redes de malha de 1mm e 2,5mm capturam um maior número de exemplares de menor porte. Na maioria dos meses de coleta as médias por rede do número de peixes e espécies, diversidade de Shannon-Wiener e a equitavidade não diferiram significativamente. Considerando-se as praias em separado, entre as redes utilizadas nas coletas não foram significativas as diferenças entre as médias do número de exemplares e equittividade, com diferenças estatísticas na média do número de peixes e diversidade de Shannon-Wiener. Através das análises de agrupamento observa-se que as redes de malha de 2,5 mm e 5,0 mm mostraram, nas praias estuarinas estudadas, assembléias similares no padrão de variação temporal, diferindo acentuadamente do padrão temporal identificado com a rede de malha de 1mm. Em termos espaciais as três redes mostraram resultados diferentes, com uma maior similaridade entre as assembléias amostradas pelas redes de 2,5 e 5mm.(AU)

Comparação de três redes para identificar a estrutura de assembléias de peixes em praias estuarinas de São Francisco do Sul, Santa Catarina / Comparison between three nets to identify the structure of fish assemblagesin estuarine beaches of São Francisco do Sul, Santa Catarina

The catchability of three type seine nets was compared in seven estuarine beaches of Sao Francisco do Sul, Santa Catarina. The capture of specimens and taxa was higher in the net 2.5 mm mesh with nets of meshes 1 and 2.5 mm showing a higher number of unique species. In general terms it was noted that the nets of meshes 1 and 2.5mm capture a greater number of specimens of smaller size. In most months the average collection for net and the number of fish species, Shannon-Wiener and equitability not differ significantly. Considering the beaches separately, between the nets used in the collections were not significant differences between the mean number of specimens and equitability, with differences in the average number of fish and Shannon-Wiener. Through cluster analysis shows that nets of meshes of 2.5 and 5.0 mm shown in estuarine beaches studied in assemblies similar pattern of temporal variation, differing markedly from the temporal pattern identified with the net of mesh 1mm. In spatial terms the three nets showed different results, with a greater similarity between the assemblages sampled by nets of 2.5 and 5mm.

A capturabilidade de três redes tipo picaré foi comparada em sete praias estuarinas de São Francisco do Sul, Santa Catarina. A captura de exemplares e taxa foi maior na rede de malha de 2,5 mm, com as redes de malhas de 1 e 2,5 mm apresentando um maior número de espécies exclusivas. Em termos gerais observou-se que as redes de malha de 1mm e 2,5mm capturam um maior número de exemplares de menor porte. Na maioria dos meses de coleta as médias por rede do número de peixes e espécies, diversidade de Shannon-Wiener e a equitavidade não diferiram significativamente. Considerando-se as praias em separado, entre as redes utilizadas nas coletas não foram significativas as diferenças entre as médias do número de exemplares e equittividade, com diferenças estatísticas na média do número de peixes e diversidade de Shannon-Wiener. Através das análises de agrupamento observa-se que as redes de malha de 2,5 mm e 5,0 mm mostraram, nas praias estuarinas estudadas, assembléias similares no padrão de variação temporal, diferindo acentuadamente do padrão temporal identificado com a rede de malha de 1mm. Em termos espaciais as três redes mostraram resultados diferentes, com uma maior similaridade entre as assembléias amostradas pelas redes de 2,5 e 5mm.

Spawning of migratory fish species between two reservoirs of the upper Uruguay River, Brazil

This study investigated the migratory fish spawning within the reservoirs of the Machadinho and Itá dams (upper Uruguay River, Brazil) and its relationship to environmental variables. Sampling was conducted in the lotic region of the river in two sites between the dams' reservoirs: Uruguay (main river) and Ligeiro (tributary). Sampling included nine consecutive reproductive periods (RP) spanning the period from 2001 to 2010 and was conducted at night on the water surface using cylindrical-conical plankton nets (0.5 mm mesh); environmental variables were also recorded. The spawning of the migratory species Salminus brasiliensis, Prochilodus lineatus, and Steindachneridion scriptum was registered: S. brasiliensis and P. lineatus spawned in the tributary river at the end of spring/beginning of summer, during flooding and during periods of high water temperature. Steindachneridion scriptum spawned in the main river at the beginning of spring. The study showed that S. brasiliensis, P. lineatus, and S. scriptum are able to spawn in small lotic river stretches within two reservoirs, but only under very specific and not common environmental conditions.(AU)

Este estudo verificou a presença de desova de peixes migradores entre os reservatórios das Usinas Hidrelétricas de Machadinho e Itá (alto rio Uruguai, Brasil), e sua relação com as variáveis ambientais. As amostragens foram realizadas na região lótica do rio Uruguai, no trecho situado entre os reservatórios de Itá e Machadinho, em duas estações de amostragem: Uruguai (Principal) e Ligeiro (Tributário). As coletas abrangeram nove períodos reprodutivos (PR) consecutivos, desde 2001 até 2010, e foram realizadas no período noturno, na superfície, com o uso de redes de plâncton do tipo cilíndrico-cônicas de malha 0,5 mm, quando também foram registradas as variáveis ambientais. O estudo registrou a desova de três espécies migradoras: Salminus brasiliensis, Prochilodus lineatus e Steindachneridion scriptum. As populações de S. brasiliensis e P. lineatus desovaram no rio tributário no final da primavera e início do verão em condições de enchentes e temperatura da água mais alta. Steindachneridion scriptum desovou no rio principal durante o início da primavera. O presente estudo mostra que S. brasiliensis, P. lineatus e S. scriptum conseguem desovar em pequenos trechos lóticos de rio entre dois reservatórios, porém em condições ambientais determinadas e pouco frequentes.(AU)

Effect of abiotic variables on fish eggs and larvae distribution in headwaters of Cuiabá River, Mato Grosso State, Brazil

Researches on ichthyoplankton seems to be an important tool to identification of spawning areas and periods for freshwater fish. Ichthyoplankton was sampled monthly in the headwaters of the Cuiabá River, upper Paraguay River basin, (Mato Grosso State, Brazil), and in four of its tributaries, between November 2007 and March 2008, to evaluate the spatial and temporal distribution of fish eggs and larvae and the influence of regional and local variables on their distribution. In total, 22,067 eggs and 1,045 larvae were collected. A significant negative correlation was found between egg density and the variables of river level and flow volume. Larval density was not significantly correlated with any of the regional variables. The egg and larval densities were significantly higher at the sampling sites in the main river. The highest densities were found in environments with greater river widths, intermediate depths and lowest values of dissolved oxygen, electrical conductivity, and transparency. Anostomidae, Zungaro zungaro, Bryconamericus spp., Pimelodus spp., Pimelodidae, Auchenipteridae, and Siluriformes were the most abundant groups of larvae, and were observed at the sampling sites in the main river. The study site is an important spawning area for migratory and, non-migratory fish species, and highlight the importance of the main river to the reproductive event, by the influence of local variables transparency and river width, which in turn maybe temporally influenced by the river level.(AU)

O estudo do ictioplâncton tem se mostrado uma importante ferramenta na identificação de áreas e períodos de desova para as espécies de peixes de água doce.Amostragens de ictioplâncton foram realizadas mensalmente na região de cabeceira do rio Cuiabá, bacia do alto rio Paraguai, (Mato Grosso, Brasil) e em quatro de seus tributários, entre novembro de 2007 e março de 2008, com o objetivo de avaliar a distribuição espaço-temporal de ovos e larvas de peixes. Foram amostrados 22.067 ovos e 1.045 larvas. Identificou-se correlação significativa e negativa entre a densidade de ovos, o nível fluviométrico e a vazão. A densidade de larvas não apresentou correlação significativa com nenhuma das variáveis regionais. As densidades, tanto de ovos quanto de larvas, foram significativamente maiores nos pontos no rio principal. As maiores abundâncias foram observadas em ambientes com maiores valores de largura do rio, valores intermediários de profundidade e menores valores de O2 dissolvido, condutividade e transparência. Os grupos taxonômicos de larvas mais abundantes foram Anostomidae, Zungaro zungaro, Bryconamericus spp., Pimelodus spp., Pimelodidae, Auchenipteridae e Siluriformes, com maiores abundâncias observadas nos pontos no rio principal. Os resultados mostram que o local de estudo é uma importante área de desova para as espécies de peixes migradores e não-migradores, e destacamos a importância do rio principal para o evento reprodutivo, pela influência das variáveis locais, transparência e largura do rio, que por sua vez parecem ser influenciadas temporalmente pelo nível fluviométrico.(AU)

Prey-capture efficiency between juveniles and adults, feeding habitat and abundance of Wattled Jacana foragers in northern Pantanal, Mato Grosso state, Brazil

The choice of foraging strategies implies an attempt at gaining energy by predators. Supposedly, the difference in employing the "sit and wait" or "active foraging" behavior lays in hunter skills, experience and the kind of prey consumed. With the hypothesis that "active foraging" demands no learning, in this study we compared the prey capture efficiency among Wattled Jacana juveniles and adults, and also present descriptive information about feeding habitat and the abundance variation of foragers throughout the day in the northern Pantanal. Prey capture efficiency did not differ significantly among juveniles and adults, corroborating our initial hypothesis that "active foraging" is an instinctive behavior and demands no experience to be effective. However, future work is necessary to compare the energetic quality of consumed items by juveniles and adults, searching for differences explained by adults' experience. Foraging individuals were found at an average distance of 14 m ranging from 2 to 42 m) from the margin of the sampled swamps, however 64% of the foragers were found closer to the margins. The average depth of foraging sites was 17 cm, ranging from 5 to 40 cm, although no preference for specific classes of depth was found (p > 0,05). Despite the accepted general pattern of birds being more active in the early morning, the largest number of individuals foraging was observed between 11:00 and 12:00 AM, but no significant difference was found in the abundance of foraging individuals among different periods of the day. Factors, which were not analyzed, such as food availability and presence of competitors and predators need to be studied to reveal the main factors of the spatial and temporal distribution of the Wattled Jacana.

A escolha de uma estratégia de forrageamento implica em uma tentativa de maximizar o ganho energético por predadores. Supostamente, a diferença em empregar o comportamento "senta e espera" ou o "forrageamento ativo" jaz sobre a habilidade de caça, a experiência e o tipo de presa consumida. A partir da hipótese de que o "forrageamento ativo" não demanda aprendizado, neste trabalho é comparada a eficiência de captura de presas entre jovens e adultos de Jaçanãs forrageadores, além de serem apresentadas informações descritivas sobre o habitat de alimentação e a variação na abundância de forrageadores ao longo do dia no Pantanal Norte. Os itens consumidos foram contabilizados para estimativas da eficiência de captura de presas, a qual não diferiu significativamente entre as classes etárias analisadas; corroborou-se, dessa forma, a hipótese inicial de que o "forrageamento ativo" é um comportamento instintivo e não demanda experiência para ter eficiência. No entanto, ainda é necessária pesquisa mais detalhada, comparando-se qualitativamente a dieta de jovens e adultos, com a intenção de testar se a experiência de adultos implica no consumo de presas com mais energia disponível. Os indivíduos forragearam, em média, a 14 m (amplitude de 2 a 42 m) de distância da margem dos brejos e lagoas amostradas; porém, 64% dos indivíduos avistados forrageavam em distâncias mais próximas da margem. A profundidade média dos locais de forrageio foi de 17 cm, com amplitude variando de 5 a 40 cm, não havendo preferência dos forrageadores por classes de profundidade específicas (p > 0,05). Apesar do padrão esperado para aves, segundo o qual a maior atividade ocorre nos momentos iniciais da manhã, o maior número de indivíduos forrageando foi observado entre 11:00 e 12:00 horas; porém, não houve diferença significativa na abundância de indivíduos forrageadores entre diferentes períodos do dia. Outros fatores, não analisados, tais como a disponibilidade alimentar e a presença de competidores e predadores, precisam ser estudados para se revelarem os principais determinantes da distribuição espacial e temporal dos Jaçanãs no Pantanal.

Distribuição espacial e sazonal de anfíbios em quatro poças na região serrana do Espírito Santo, sudeste do Brasil: influência de corredores florestais

This study evaluated the composition of anuran assemblages, and also the spatial and temporal distribution of those species in four permanent ponds. Two of these ponds are connected to Atlantic rainforest fragments by forest corridor and the other two are surrounded by Eucalyptus plantation and human settlement. Twenty-two species from five families were recorded from December 2003 to November 2004. Most species and individuals collected belong to Hylidae, which presented pronounced spatial overlap. Vegetation under 0.60 m was the most used calling site. Although not statistically supported, species richness and abundance were higher in rainy than dry months. Ponds with corridors had higher species richness and fourteen species were exclusively found on these ponds. The community structure of anurans in permanent ponds at this fragmented landscape is apparently dictated by the presence or absence of forest corridors connecting ponds to forest fragments.

Este estudo avaliou a composição da anurofauna, bem como a distribuição espacial e temporal das espécies em quatro poças permanentes em uma região montanhosa do Espírito Santo, sudeste do Brasil. Duas dessas poças são conectadas a fragmentos florestais por corredores florestais e as outras duas poças são circundadas por plantação de eucalipto e habitação humana. Foram registradas 22 espécies, incluídas em cinco famílias, entre dezembro de 2003 a novembro de 2004. Hylidae foi a mais rica e abundante, apresentando elevada sobreposição espacial. Nove espécies foram coletadas em vegetação abaixo de 0,60 m, sendo o sítio de vocalização mais utilizado. Riqueza de espécies e abundância foram maiores em meses chuvosos. Poças com corredores abrigaram maior riqueza de espécies. Adicionalmente quatorze espécies foram exclusivamente encontradas nessas poças. A estrutura da comunidade de anuros em poças permanentes nessa paisagem fragmentada é aparentemente determinada pela presença ou ausência de corredores florestais conectando fragmentos em topos de morro às poças d'água ocorrentes ao longo dos vales.

Distribuição espacial e sazonal de anfíbios em quatro poças na região serrana do Espírito Santo, sudeste do Brasil: influência de corredores florestais

This study evaluated the composition of anuran assemblages, and also the spatial and temporal distribution of those species in four permanent ponds. Two of these ponds are connected to Atlantic rainforest fragments by forest corridor and the other two are surrounded by Eucalyptus plantation and human settlement. Twenty-two species from five families were recorded from December 2003 to November 2004. Most species and individuals collected belong to Hylidae, which presented pronounced spatial overlap. Vegetation under 0.60 m was the most used calling site. Although not statistically supported, species richness and abundance were higher in rainy than dry months. Ponds with corridors had higher species richness and fourteen species were exclusively found on these ponds. The community structure of anurans in permanent ponds at this fragmented landscape is apparently dictated by the presence or absence of forest corridors connecting ponds to forest fragments.

Este estudo avaliou a composição da anurofauna, bem como a distribuição espacial e temporal das espécies em quatro poças permanentes em uma região montanhosa do Espírito Santo, sudeste do Brasil. Duas dessas poças são conectadas a fragmentos florestais por corredores florestais e as outras duas poças são circundadas por plantação de eucalipto e habitação humana. Foram registradas 22 espécies, incluídas em cinco famílias, entre dezembro de 2003 a novembro de 2004. Hylidae foi a mais rica e abundante, apresentando elevada sobreposição espacial. Nove espécies foram coletadas em vegetação abaixo de 0,60 m, sendo o sítio de vocalização mais utilizado. Riqueza de espécies e abundância foram maiores em meses chuvosos. Poças com corredores abrigaram maior riqueza de espécies. Adicionalmente quatorze espécies foram exclusivamente encontradas nessas poças. A estrutura da comunidade de anuros em poças permanentes nessa paisagem fragmentada é aparentemente determinada pela presença ou ausência de corredores florestais conectando fragmentos em topos de morro às poças d'água ocorrentes ao longo dos vales.

Estructura de la comunidad de macroinvertebrados del arroyo Achiras (Córdoba, Argentina): análisis previo a la construcción de una presa

La regulación de ríos y arroyos mediante diques modifica parámetros que influyen directamente sobre la biota. En la cuenca endorreica Achiras-del Gato ha finalizado recientemente la construcción de una presa de mediana envergadura que alterará las características limnológicas del sistema y la estructura de las comunidades bentónicas. Este estudio aporta los primeros registros del macrobentos de este sistema lótico y analiza la variación espacio-temporal de la estructura de la comunidad en tramos pedemontanos del arroyo Achiras. Durante un año, antes de la construcción de la presa, se colectaron muestras de zoobentos y se registraron variables abióticas en correderas y rabiones de dos sitios del arroyo, uno situado río arriba del área del dique y otro aguas abajo de la misma. Para cada sitio, hábitat y estación del año se determinó abundancia, frecuencia, riqueza taxonómica, Índice de Shannon y equidad, y se analizaron mediante ANOVA de una y tres vías. Los atributos de las comunidades de referencia se complementaron con la determinación de taxa exclusivos e indicadores y detectores ecológicos. En el primer sitio se registraron 73 taxa, Simulium fue más abundante y Leptohyphes eximius Eaton, 1882, más frecuente. En el segundo se hallaron 75 taxa, Caenis fue más abundante y Cricotopus sp. 3 más frecuente. La abundancia y la riqueza fueron significativamente mayores en primavera, y la diversidad en rabiones de invierno. Se determinó que los atributos de la comunidad estuvieron afectados por la época de muestreo. El arroyo Achiras posee un régimen hídrico freático-pluvial, con caudales bajos en invierno y altos en verano, por lo que se esperan cambios en la biota nativa y la integridad del sistema en respuesta a la reducción de la variabilidad hidráulica cuando el funcionamiento de la presa altere el caudal natural.

Regulation of rivers and streams modifies parameters that directly influence on the biota. In Achiras-del Gato endorheic basin has completed the construction of a midsize dam that will alter the limnological characteristics of the system and the structure of benthic communities. This study provides the first taxonomic records of macrobenthos of this lotic system and analyzes the spatial and temporal variations of the community structure in the foothills stretches of Achiras stream. Zoobenthos samples were collected and abiotic variables were recorded in runs and riffles, during a year, in two sites located upstream and downstream of the dam area, prior to the dam was built. For each site, habitat and season we determined the abundance, frequency, taxonomic richness, Shannon and evenness, and the data were analyzed using one-way and three-way ANOVA. Attributes of the reference communities were complemented by the determination of ecological indicators and detectors, and exclusive taxa. In the first site 73 taxa were recorded, Simulium was the most abundant and Leptohyphes eximius Eaton, 1882, was the most frequent. In the second site we found 75 taxa, Caenis was the most abundant and Cricotopus sp. 3, was the most frequent. In this study composition and distribution of the biota and indicators taxa are discussed. We determined that the community attributes were affected by the hydrological periods in wich the samples were taken. Achiras stream has a phreatic-pluvial hydrological regime with low flows in winter and high flows in summer. Therefore, we expect changes in native biota and in system integrity in response to hydraulic variability reduction when Achiras dam start functioning and alters the natural flow.

Estructura de la comunidad de macroinvertebrados del arroyo Achiras (Córdoba, Argentina): análisis previo a la construcción de una presa

La regulación de ríos y arroyos mediante diques modifica parámetros que influyen directamente sobre la biota. En la cuenca endorreica Achiras-del Gato ha finalizado recientemente la construcción de una presa de mediana envergadura que alterará las características limnológicas del sistema y la estructura de las comunidades bentónicas. Este estudio aporta los primeros registros del macrobentos de este sistema lótico y analiza la variación espacio-temporal de la estructura de la comunidad en tramos pedemontanos del arroyo Achiras. Durante un año, antes de la construcción de la presa, se colectaron muestras de zoobentos y se registraron variables abióticas en correderas y rabiones de dos sitios del arroyo, uno situado río arriba del área del dique y otro aguas abajo de la misma. Para cada sitio, hábitat y estación del año se determinó abundancia, frecuencia, riqueza taxonómica, Índice de Shannon y equidad, y se analizaron mediante ANOVA de una y tres vías. Los atributos de las comunidades de referencia se complementaron con la determinación de taxa exclusivos e indicadores y detectores ecológicos. En el primer sitio se registraron 73 taxa, Simulium fue más abundante y Leptohyphes eximius Eaton, 1882, más frecuente. En el segundo se hallaron 75 taxa, Caenis fue más abundante y Cricotopus sp. 3 más frecuente. La abundancia y la riqueza fueron significativamente mayores en primavera, y la diversidad en rabiones de invierno. Se determinó que los atributos de la comunidad estuvieron afectados por la época de muestreo. El arroyo Achiras posee un régimen hídrico freático-pluvial, con caudales bajos en invierno y altos en verano, por lo que se esperan cambios en la biota nativa y la integridad del sistema en respuesta a la reducción de la variabilidad hidráulica cuando el funcionamiento de la presa altere el caudal natural.

Regulation of rivers and streams modifies parameters that directly influence on the biota. In Achiras-del Gato endorheic basin has completed the construction of a midsize dam that will alter the limnological characteristics of the system and the structure of benthic communities. This study provides the first taxonomic records of macrobenthos of this lotic system and analyzes the spatial and temporal variations of the community structure in the foothills stretches of Achiras stream. Zoobenthos samples were collected and abiotic variables were recorded in runs and riffles, during a year, in two sites located upstream and downstream of the dam area, prior to the dam was built. For each site, habitat and season we determined the abundance, frequency, taxonomic richness, Shannon and evenness, and the data were analyzed using one-way and three-way ANOVA. Attributes of the reference communities were complemented by the determination of ecological indicators and detectors, and exclusive taxa. In the first site 73 taxa were recorded, Simulium was the most abundant and Leptohyphes eximius Eaton, 1882, was the most frequent. In the second site we found 75 taxa, Caenis was the most abundant and Cricotopus sp. 3, was the most frequent. In this study composition and distribution of the biota and indicators taxa are discussed. We determined that the community attributes were affected by the hydrological periods in wich the samples were taken. Achiras stream has a phreatic-pluvial hydrological regime with low flows in winter and high flows in summer. Therefore, we expect changes in native biota and in system integrity in response to hydraulic variability reduction when Achiras dam start functioning and alters the natural flow.

Spatial and temporal distribution of Pseudis minuta (Anura, Hylidae, Hylinae) and environmental variables related to its reproductive activity in Reserva Biológica do Lami, southern Brazil

We studied the reproductive biology of a population of Pseudis minuta Günther, 1858 from Reserva Biológica do Lami (30º 15' S; 51º 05' W), Porto Alegre, southern Brazil. We assessed the spatial and temporal distribution of individuals (males, females, juveniles) and explored potential relationships with environmental variables. Field activities encompassed bimonthly surveys in three semi-permanent ponds, each one during approximately two days and two nights, from August 2004 to July 2005. We recorded differences in the sites used by males, females and juveniles, with males occupying deeper and more distant places from the border. The temporal distributions of individuals, calling sites and amplectant pairs indicated that the reproductive activity of P. minuta is related to some of the studied abiotic factors. Calling males presented statistical differences in relation to non-calling males for all daily abiotic variables analyzed (air temperature, water temperature, relative humidity and rainfall), as well as to monthly temperature and rainfall. The number of active males, females and juveniles was influenced by at least one of the daily or monthly environmental variables analyzed. We conclude that the reproduction in this species is seasonal and may be partially determined by abiotic factors.

A distribuição espacial e temporal de Pseudis minuta Günther, 1858 e fatores ambientais relacionados à atividade reprodutiva da espécie foram estudados na Reserva Biológica do Lami (30º 15' S; 51º 05' W), Porto Alegre, Brasil. As atividades de campo compreenderam visitas bimensais a três banhados semi-permanentes, com duração aproximada de dois dias e duas noites cada, entre agosto de 2004 e julho de 2005. Observaram-se diferenças nos sítios utilizados por machos, fêmeas e juvenis, com machos ocupando locais mais profundos e mais distantes da margem. A distribuição temporal dos indivíduos, vocalizações e amplexos indicaram que a atividade reprodutiva de P. minuta está relacionada com alguns dos fatores abióticos estudados. Os machos em atividade de vocalização apresentaram diferença significativa em relação aos machos não vocalizantes para todos os fatores abióticos diários analisados (temperatura do ar, temperatura da água, umidade relativa do ar e pluviosidade), bem como na temperatura do ar e pluviosidade mensais. O número de machos, fêmeas e juvenis em atividade foi influenciada por pelo menos um dos fatores ambientais mensais ou diários analisados. Conclui-se que a reprodução desta espécie é sazonal e parcialmente determinada por fatores abióticos.