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Evaluating the use of predatory insects as bioindicators of metals contamination due to sugarcane cultivation in neotropical streams

CORBI, Juliano Jose; FROEHLICH, Claudio Gilberto; TRIVINHO-STRIXINO, Susana; SANTOS, Ademir dos
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.59%
Streams located in areas of sugarcane cultivation receive high concentrations of metal ions from soils of the adjacent areas causing accumulation of metals in the aquatic sediment. This impact results in environmental problems and leads to bioaccumulation of metal ions in aquatic organisms. In the present study, metal concentrations in different predatory insects were studied in streams near sugarcane cultivation and compared to reference sites. Possible utilisation of predatory insects as bioindicators of metal contamination due to sugarcane cultivation from 13 neotropical streams was evaluated. Ion concentrations of Al, Cd, Cr, Cu, Zn, Fe, and Mn in adult Belostomatidae (Hemiptera) and in larvae of Libellulidae (Odonata) were analysed. Nine streams are located in areas with sugarcane cultivation, without riparian vegetation (classified as impacted area) and four streams were located in forested areas (reference sites). Metal concentrations in insects were higher near sugarcane cultivations than in control sites. Cluster analysis, complemented by an ANOSIM test, clearly showed that these insect groups are good potential bioindicators of metal contamination in streams located in areas with sugarcane cultivation and can be used in monitoring programmes. We also conclude that Libellulidae appeared to accumulate higher concentrations of metals than Belostomatidae.; FAPESP (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo)[06/61400-2]

Relação entre uso da terra e composição de insetos aquáticos em quatro bacias hidrográficas do Estado de São Paulo; Relationship of land use and composition of aquatic insects from four watersheds of São Paulo State

Sonoda, Kathia Cristhina
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 30/06/2005 PT
Relevância na Pesquisa
56.74%
1. Avaliar diferenças nas comunidades de insetos aquáticos de quatro bacias hidrográficas do estado de São Paulo com diferentes graus de ocupação, relacionando-as em função dos usos da terra e declividade do terreno na sub-bacia a montante dos locais de coleta e em uma zona tampão de 50m, assim como em função de variáveis químicas e físicas da água. 2. Avaliar alterações nas comunidades de insetos aquáticos provenientes de locais com presença ou ausência de mata ripária nas margens. Os dados referem-se às coletas de insetos aquáticos com cestos com substrato artificial; estes ficaram 44 dias em exposição, entre agosto e outubro de 2002. As bacias estudadas foram Alto Paranapanema, Peixe, Aguapeí e São José dos Dourados. Para o primeiro estudo, seis amostras de cada rio foram tomadas, cujas faunas foram identificadas e contadas; Chironomidae foram identificados em nível genérico, os demais insetos, em família. Para interpretação dos resultados, utilizou-se números absoluto e percentual de indivíduos e táxons; índices de diversidade, riqueza, uniformidade e quantidade de táxons de Ephemeroptera, Plecoptera e Trichoptera. Para o geoprocessamento, a partir de mapas digitais, delimitou-se a sub-bacia a montante dos locais de coleta e a zona tampão de 50m ao redor dos rios...

Partição da diversidade de insetos aquáticos em riachos do sul do Brasil; Partitioning diversity of aquatic insects in streams of the Southern Brazil

Hepp, Luiz Ubiratan
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Tese de Doutorado Formato: application/pdf
POR
Relevância na Pesquisa
46.55%
O presente estudo teve por objetivo principal avaliar a distribuição espacial de insetos aquáticos (Ephemeroptera, Plecoptera e Trichoptera; EPT) em riachos do Sul do Brasil. Para tanto, foram realizados diferentes estudos com objetivos específicos direcionados a (i) avaliar o efeito de fatores ambientais e espaciais sobre a distribuição dos organismos, (ii) verificar as escalas heirárquicas onde ocorreram maior variação da comunidade (diversidade beta), (iii) testar a existência de relação entre a composição de espécies e diferentes distâncias espaciais e (iv) avaliar a importância da inclusão de espécies raras na diversidade beta de insetos aquáticos. No primeiro estudo, realizado em Maquiné-RS, observei que os preditores ambientais possuem maior importância na explicação da diversidade beta das comunidades do que a distância entre os trechos . No segundo estudo, em São José dos Ausentes–RS, particionei a diversidade em múltiplas escalas. A partição aditiva utilizada demonstrou que as escalas maiores (riachos e microbacias) foram as de maior importância para estruturação da comunidade. No último estudo, utilizei um método de decomposição da variância da comunidade em múltiplas escalas espaciais utilizando uma matriz biológica contendo toda a fauna de EPT coletada e outra matriz com exclusão das espécies raras. Neste estudo foi possível observar que a variação existente nas escalas de corredeiras...

Aquatic insects as the main food resource of fish the community in a Neotropical reservoir

Vidotto-Magnoni, Ana Paula; Carvalho, Edmir Daniel
Fonte: Sociedade Brasileira de Ictiologia Publicador: Sociedade Brasileira de Ictiologia
Tipo: Artigo de Revista Científica Formato: 701-708
ENG
Relevância na Pesquisa
46.72%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Processo FAPESP: 02/11113-6; Neste estudo foi avaliada a dieta das espécies de peixes do reservatório de Nova Avanhandava, baixo rio Tietê, Estado de São Paulo, Brasil. Os peixes foram coletados em dois trechos do reservatório: trecho Santa Bárbara (14 coletas) e trecho Bonito (duas coletas) entre setembro de 2002 e março de 2004, utilizando-se de redes de espera e arrasto. Os resultados das análisesde conteúdo estomacal foram expressos em frequência de ocorrência e método gravimétrico, combinados no Índice Alimentar (IAi). As 20 espécies analisadas consumiram um total de 52 itens, agrupados em 10 categorias alimentares: insetos aquáticos, insetos terrestres, crustáceos, peixes, macroinvertebrados, microcrustáceos, algas, material vegetal, detrito/sedimento e escamas. Os insetos aquáticos (principalmente Chironomidae, Odonata e Ephemeroptera) foram o recurso alimentar mais comum na dieta, consumido por 18 espécies. A análise da dieta da comunidade (espécies agrupadas) revelou que a categoria alimentar dominante foi insetos aquáticos (IAi = 77.6%), seguida pelos crustáceos (IAi = 7.1%). Quatro guildas tróficas foram identificadas pela análise de agrupamento (distância de Pearson): insetívoros (10 espécies)...

Diet and trophic groups of an aquatic insect community in a tropical stream

Motta, R. L.; Uieda, Virginia Sanches
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: 809-817
ENG
Relevância na Pesquisa
56.55%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Processo FAPESP: 90/2410-8; Processo FAPESP: 91/0612-5; A dieta e o grupo trófico de uma assembléia de insetos aquáticos foi estudada em um riacho tropical. Os gêneros de algumas ordens de insetos, como Lepidoptera, Ephemeroptera, Plecoptera, Odonata e Hemiptera, apresentaram especialização alimentar. Por outro lado, as ordens Trichoptera, Coleoptera e Diptera mostraram grande variação na dieta, com gêneros de diferentes grupos tróficos. Alguns gêneros das ordens Trichoptera, Lepidoptera, Coleoptera e Diptera apresentaram variação sazonal na dieta relacionada a mudanças na composição da comunidade e à dieta generalista desses gêneros. Entretanto, a comparação sazonal de grupos tróficos mostrou diferenças não significativas estatisticamente. A grande importância da matéria orgânica, um recurso não limitado, na dieta dos insetos aquáticos no Ribeirão do Atalho pode ser a explicação para a estabilidade da organização trófica dessa comunidade.; The diet and trophic groups of an assemblage of aquatic insects were studied in a tropical stream. Genera of the orders Ephemeroptera...

Spatial and temporal organization of aquatic insects assemblages in the longitudinal gradient of a tropical river

BAPTISTA,D. F.; DORVILLÉ,L. F. M.; BUSS,D. F.; NESSIAMIAN,J. L.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/05/2001 EN
Relevância na Pesquisa
56.55%
The distribution and abundance of aquatic insects were studied in the longitudinal gradient of the watershed of Macaé River, a coastal Atlantic Forest river in South-eastern Brazil. Sampling stations were selected in the first, second, fourth, fifth, and sixth orders and sampled in April, July, and October 1995. This represented the end of the rainy season, the dry season, and the beginning of another rainy season, respectively. In each month four samples were collected using a Surber sampler from each of the following substrates: sand, litter deposited in pool areas, litter in riffle areas, and stones. A total of 46,431 specimens of aquatic insects belonging to ten orders were obtained. The data were analyzed by the multivariate methodologies of Correspondence Analysis (CA) and Cluster Analysis (UPGMA) using the similarity index of Morisita, for all three months. Both showed a significant faunal disrupture in the river, which can be divided in two sections: the upper one, from first to fourth orders, and the lower section, including fifth and sixth orders. The same results were obtained with presence-absence matrices, using Jaccard similarity index, showing that the changes are not only due to quantitative differences. A Mantel test was used to compare the assemblage composition temporally and no difference was detected between the three months. Moreover...

Diet and trophic groups of an aquatic insect community in a tropical stream

Motta,R. L.; Uieda,V. S.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/11/2004 EN
Relevância na Pesquisa
56.55%
The diet and trophic groups of an assemblage of aquatic insects were studied in a tropical stream. Genera of the orders Ephemeroptera, Odonata, Plecoptera, Lepidoptera, and Hemiptera showed feeding specialization. Others, such as Trichoptera, Coleoptera, and Diptera, showed great diet variation with genera of different trophic groups. Seasonal variation of insect diet, evident only for some genera of the orders Trichoptera, Lepidoptera, Coleoptera, and Diptera, was due to the differences observed in community composition and to generalist habits of these genera. However, the seasonal comparison of trophic groups showed no significant statistical differences. The great importance of organic matter, a non-limited resource, in the diet of Ribeirão do Atalho aquatic insects may be the explanation for the trophic stability in this community organization.

Aquatic insects as the main food resource of fish the community in a Neotropical reservoir

Vidotto-Magnoni,Ana Paula; Carvalho,Edmir Daniel
Fonte: Sociedade Brasileira de Ictiologia Publicador: Sociedade Brasileira de Ictiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2009 EN
Relevância na Pesquisa
46.72%
We evaluated the feeding of fish species of the Nova Avanhandava Reservoir, low Tietê River, São Paulo State, Brazil. Fishes were collected in two stretches of the reservoir: Santa Bárbara (14 samples) and Bonito (two samples) between September 2002 and March 2004, using gill and seining nets. The results of stomach contents analysis were expressed with the frequency of occurrence and gravimetric method, combined in the Alimentary Index (AI). The 20 species studied consumed 52 food items, grouped in 10 food categories: aquatic insects, terrestrial insects, crustaceans, fish, macroinvertebrates, microcrustaceans, algae, vegetal matter, detritus/sediment and scales. The aquatic insects (mainly Chironomidae, Odonata and Ephemeroptera) were the most common food resources, consumed by 18 species. The diet composition of the community (species grouped) indicated that the dominant food category in the diet of fishes was aquatic insects (AI = 77.6%), followed by crustaceans (AI = 7.1%). Four trophic guilds were identified according a cluster analysis (Pearson distance): insectivorous (10 species), omnivorous (4 species), detritivorous (3 species) and piscivorous/carcinophagous (3 species). Despite the highest number of species, the insectivorous guild was responsible for more than 80% in captures in number and biomass (CPUEn and CPUEb). The low values of niche breadth presented by all species...

Aquatic Insects as a Vector for Mycobacterium ulcerans

Marsollier, Laurent; Robert, Raymond; Aubry, Jacques; André, Jean-Paul Saint; Kouakou, Henri; Legras, Pierre; Manceau, Anne-Lise; Mahaza, Chetaou; Carbonnelle, Bernard
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /09/2002 EN
Relevância na Pesquisa
46.72%
Mycobacterium ulcerans is an emerging environmental pathogen which causes chronic skin ulcers (i.e., Buruli ulcer) in otherwise healthy humans living in tropical countries, particularly those in Africa. In spite of epidemiological and PCR data linking M. ulcerans to water, the mode of transmission of this organism remains elusive. To determine the role of aquatic insects in the transmission of M. ulcerans, we have set up an experimental model with aquariums that mimic aquatic microenvironments. We report that M. ulcerans may be transmitted to laboratory mice by the bite of aquatic bugs (Naucoridae) that are infected with this organism. In addition, M. ulcerans appears to be localized exclusively within salivary glands of these insects, where it can both survive and multiply without causing any observable damage in the insect tissues. Subsequently, we isolated M. ulcerans from wild aquatic insects collected from a zone in the Daloa region of Ivory Coast where Buruli ulcer is endemic. Taken together, these results point to aquatic insects as a possible vector of M. ulcerans.

Why do red and dark-coloured cars lure aquatic insects? The attraction of water insects to car paintwork explained by reflection–polarization signals

Kriska, György; Csabai, Zoltán; Boda, Pál; Malik, Péter; Horváth, Gábor
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.7%
We reveal here the visual ecological reasons for the phenomenon that aquatic insects often land on red, black and dark-coloured cars. Monitoring the numbers of aquatic beetles and bugs attracted to shiny black, white, red and yellow horizontal plastic sheets, we found that red and black reflectors are equally highly attractive to water insects, while yellow and white reflectors are unattractive. The reflection–polarization patterns of black, white, red and yellow cars were measured in the red, green and blue parts of the spectrum. In the blue and green, the degree of linear polarization p of light reflected from red and black cars is high and the direction of polarization of light reflected from red and black car roofs, bonnets and boots is nearly horizontal. Thus, the horizontal surfaces of red and black cars are highly attractive to red-blind polarotactic water insects. The p of light reflected from the horizontal surfaces of yellow and white cars is low and its direction of polarization is usually not horizontal. Consequently, yellow and white cars are unattractive to polarotactic water insects. The visual deception of aquatic insects by cars can be explained solely by the reflection–polarizational characteristics of the car paintwork.

Anthropogenic Impacts on Aquatic Insects in Six Streams of South Western Ghats

Dinakaran, S.; Anbalagan, S.
Fonte: University of Wisconsin Library Publicador: University of Wisconsin Library
Tipo: Artigo de Revista Científica
Publicado em 04/06/2007 EN
Relevância na Pesquisa
46.69%
Diversity patterns of aquatic insects among sampling sites lying with!ç the unprotected and protected areas of Western Ghats were studied. This study primarily emphasizes whether anthropogenic influence is the prime cause for the presence of aquatic insects especialIy of pollution-sensitive organisms belonging to the orders Ephemeroptera, Plecoptera and Trichoptera, or to factors such as the physico-chemical features of the water, or sampling methods. Six streams were sampled quantitatively, of which three streams (Abbifalls, Monkey falls and SiIver Cascade) were within protected areas and the remaining three streams (Kumbakarai, Shenbagadevi and Manimutharu falls) were in unprotected areas. A total of 3,209 individual aquatic insects belonging to 25 genera, 18 families and 7 orders were collected. The highest species richness and abundance was observed in Monkey falls followed by Kumbakkarai falls. Large çumbers of more habitat-sensitive organisms such as Ecdyonurus sp., Epeorus sp., Thalerosphyrus sp., Euthraulus sp., and Nathanella sp., were found in Monkey falls. Though the species assemblage was somewhat different, pollution-sensitive taxa were also observed in Kumbakkarai falls. Shenbagadevi and Manimutharu falls had a lower diversity of aquatic insects. The likely causes of these differences are discussed.

A Review of Chemosensation and Related Behavior in Aquatic Insects

Crespo, José G.
Fonte: University of Wisconsin Library Publicador: University of Wisconsin Library
Tipo: Artigo de Revista Científica
Publicado em 17/05/2011 EN
Relevância na Pesquisa
46.72%
Insects that are secondarily adapted to aquatic environments are able to sense odors from a diverse array of sources. The antenna of these insects, as in all insects, is the main chemosensory structure and its input to the brain allows for integration of sensory information that ultimately ends in behavioral responses. Only a fraction of the aquatic insect orders have been studied with respect to their sensory biology and most of the work has centered either on the description of the different types of sensilla, or on the behavior of the insect as a whole. In this paper, the literature is exhaustively reviewed and ways in which antennal morphology, brain structure, and associated behavior can advance better understanding of the neurobiology involved in processing of chemosensory information are discussed. Moreover, the importance of studying such group of insects is stated, and at the same time it is shown that many interesting questions regarding olfactory processing can be addressed by looking into the changes that aquatic insects undergo when leaving their aquatic environment.

Who Eats Whom in a Pool? A Comparative Study of Prey Selectivity by Predatory Aquatic Insects

Klecka, Jan; Boukal, David S.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 05/06/2012 EN
Relevância na Pesquisa
46.61%
Predatory aquatic insects are a diverse group comprising top predators in small fishless water bodies. Knowledge of their diet composition is fragmentary, which hinders the understanding of mechanisms maintaining their high local diversity and of their impacts on local food web structure and dynamics. We conducted multiple-choice predation experiments using nine common species of predatory aquatic insects, including adult and larval Coleoptera, adult Heteroptera and larval Odonata, and complemented them with literature survey of similar experiments. All predators in our experiments fed selectively on the seven prey species offered, and vulnerability to predation varied strongly between the prey. The predators most often preferred dipteran larvae; previous studies further reported preferences for cladocerans. Diet overlaps between all predator pairs and predator overlaps between all prey pairs were non-zero. Modularity analysis separated all primarily nectonic predator and prey species from two groups of large and small benthic predators and their prey. These results, together with limited evidence from the literature, suggest a highly interconnected food web with several modules, in which similarly sized predators from the same microhabitat are likely to compete strongly for resources in the field (observed Pianka’s diet overlap indices >0.85). Our experiments further imply that ontogenetic diet shifts are common in predatory aquatic insects...

Efeito de distúrbio causado pelo despejo de efluente orgânico sobre a comunidade de insetos aquáticos; Effect of disturbance caused by dumping of organic waste in the community of aquatic insects

ARAÚJO, Cecília Santiago do Carmo
Fonte: Universidade Federal de Goiás; BR; UFG; Mestrado em Ecologia e Evolução; Ciências Biológicas - Biologia Publicador: Universidade Federal de Goiás; BR; UFG; Mestrado em Ecologia e Evolução; Ciências Biológicas - Biologia
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
66.72%
Among several environmental impacts caused by human activities, the release of domestic and industrial effluents has been major disturbances that cause degradation of water quality in natural systems by altering their physical, chemical and biological features. For this reason, the aim of this work was to evaluate the effect of discharging organic waste from five Sewage Treatment Plants (STP) on abundance, richness and composition of aquatic insect fauna present in streams receiving sewage, in addition to test the hypotheses that i) disturbance caused by the discharge of effluents from STP alters the abundance of some groups of aquatic insects in the site downstream when compared to the upstream of site and ii) the taxonomic composition of the downstream impact of STPs is modified by the presence of resistant taxa.Thus, the sampling of aquatic insects and measures of some limnological variable was carried out during the drought of 2010, with the Surber sampler, 100m upstream and 100m downstream from the effluent discharge. Chironomidae and EPT larvaes (Ephemeroptera, Plecoptera and Trichoptera) were identified to genus. To test the hypothesis, a paired t test was performed with logarithmic data of total abundance, a paired t test with the richness of taxa identified at family and genus level. To evaluate the composition of the taxa sampled in two parts in relation to environmental variables were carried out two CCA separately...

Indicadores ecológicos multi-escala para avaliação de comunidades de macroinvertebrados aquáticos na bacia do rio dos bois-Go; Biological indicators to evaluate communities of aquatic insects of the bois river basin, Goiás, Brazil

Silveira, Allan Valle Toledo da
Fonte: Universidade Federal de Goiás; Brasil; UFG; Programa de Pós-graduação em Ciências Ambientais (PRPG); Pró-Reitoria de Pós-graduação (PRPG) Publicador: Universidade Federal de Goiás; Brasil; UFG; Programa de Pós-graduação em Ciências Ambientais (PRPG); Pró-Reitoria de Pós-graduação (PRPG)
Tipo: Tese de Doutorado Formato: application/pdf
POR
Relevância na Pesquisa
56.72%
This thesis evaluated the variables that influence the distribution of aquatic insects, along different spatial scales, aiming to establish a biologic index of water quality based on these organisms. The study area was the Rio dos Bois watershed, one of the most important from Goiás State, due to its vocation for agricultural and cattle production. Thus, the community of aquatic insects occurring in forty two streams was sampled, as well as a series of water physicochemical variables. Surrounding the streams (up to a distance of 200 m), and along the watershed above the sampling units, percentages of land use (agriculture, pasture and native vegetation) were estimated based on LandSat 5/TM satellite images from July 2012. The main results showed that (1) smaller spatial scales seem to provide better estimates of water quality and aquatic insects community than the watershed level scale, being recommended to use habitat integrity indexes (HII); (2) the variance partition held to define the contribution of the spatial processes and environmental variables on the community structure of aquatic insects did not present statistically significant values to corroborate none of the two sets of predictors and (3) only four from the 26 biodiversity metrics studied were enough to compose a multimetric index for the watershed...

Effects of forest conversion on the assemblages' structure of aquatic insects in subtropical regions

Bertaso,Tiago R.N.; Spies,Marcia R.; Kotzian,Carla B.; Flores,Maria L.T.
Fonte: Sociedade Brasileira De Entomologia Publicador: Sociedade Brasileira De Entomologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2015 EN
Relevância na Pesquisa
56.46%
The effects of forest conversion to agricultural land uses on assemblages of aquatic insects were analyzed in subtropical streams. Organisms and environmental variables were collected in six low-order streams: three streams located in a forested area, and three in areas converted to agricultural land uses. We expected that the aquatic insects' assemblage attributes would be significantly affected by forest conversion, as well as by environmental variables. Streams in converted areas presented lower species richness, abundance and proportion of sensitive insect taxa. The ANOSIM test evidenced strong difference in EPT assemblage structure between streams of forested and converted areas. The ISA test evidenced several EPT genera with high specificity to streams in forested areas and only one genus related to streams in converted areas. Thus, the impacts of the conversion of forested area to agricultural land uses have significantly affected the EPT assemblages, while environmental variables were not affected. We suggest that the effects detected can be influenced by two processes related to vegetation cover: i) lower input of allochthonous material, and ii) increased input of fine sediments in streams draining converted areas.

Concentration changes of organochlorine compounds and polybromodiphenyl ethers during metamorphosis of aquatic insects

Bartrons Vilamala, Mireia; Grimalt, Joan O.; Catalán, Jordi
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artículo Formato: 19968 bytes; application/msword
ENG
Relevância na Pesquisa
56.4%
5 pages, 3 figures.-- PMID: 17937293 [PubMed].-- Printed version published on Sep 1, 2007.; The role of insect larvae and pupae as sources of organochlorine compounds (OCs) and polybromodiphenyl ethers (PBDEs) in freshwater food webs for high predators such as fish is evaluated. Trichoptera and diptera have been taken as organisms of choice for such comparison because they are common in benthic aquatic habitats and accumulate substantial amounts of these compounds. Hexachlorobenzene, hexachlorocyclohexanes, 4,4'DDE, 4,4'DDT, polychlorobiphenyls, and PBDEs have been measured. The results show a nonselective enrichment of OCs and PBDEs from larvae to pupae. These concentration increases may result from the weight loss of pupae during metamorphosis as a consequence of mainly protein carbon respiration and lack of feeding. Despite the lack of change in total amount, the concentration increases from larvae to pupae are very relevant for the pollutant ingestion of the higher predators. The intakes of OCs and PBDEs by trout are between 2- and 5-fold higher per calorie gained when predating on pupae than on larvae. Since pollutant concentration, energy reward, predation susceptibility, and duration of life stage are very different between these two insect stages...

Diversity and distribution of aquatic insects in Southern Brazil wetlands: implications for biodiversity conservation in a Neotropical region

Maltchik,Leonardo; Schmidt Dalzochiov,Marina; Stenert,Cristina; Rolon,Ana Silvia
Fonte: Revista de Biología Tropical Publicador: Revista de Biología Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2012 EN
Relevância na Pesquisa
56.7%
The selection of priority areas is an enormous challenge for biodiversity conservation. Some biogeographic methods have been used to identify the priority areas to conservation, and panbiogeography is one of them. This study aimed at the utilization of panbiogeographic tools, to identify the distribution patterns of aquatic insect genera, in wetland systems of an extensive area in the Neotropical region (~280 000km²), and to compare the distribution of the biogeographic units identified by the aquatic insects, with the conservation units of Southern Brazil. We analyzed the distribution pattern of 82 genera distributed in four orders of aquatic insects (Diptera, Odonata, Ephemeroptera and Trichoptera) in Southern Brazil wetlands. Therefore, 32 biogeographic nodes corresponded to the priority areas for conservation of the aquatic insect diversity. Among this total, 13 were located in the Atlantic Rainforest, 16 in the Pampa and three amongst both biomes. The distribution of nodes showed that only 15% of the dispersion centers of insects were inserted in conservation units. The four priority areas pointed by node cluster criterion must be considered in further inclusions of areas for biodiversity conservation in Southern Brazil wetlands...

Dry mass estimates of some tropical aquatic insects

Cressa,Claudia
Fonte: Revista de Biología Tropical Publicador: Revista de Biología Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/1999 EN
Relevância na Pesquisa
56.4%
Relationships of body mass and head capsule width were developed for Thraulodes sp., Haplohyphes sp. (Ephemeroptera), Leptonema sp., Phylloicus sp. Nectopsyche sp. (Trichoptera), and Anacroneuria sp. (Plecoptera). The organisms were collected with a Surber net (0.1296 m² and 0.286 mm mesh size) on the Orituco river, Venezuela. The number of specimens used in the analysis for the species studied, was different (from 84 to 103 specimens). Regression analysis indicated that all relationships were best expressed by a power function rather than by linear or exponential equation. Analyses of the relationships reveal interspecific differences among insects of the same order. Species-specific relationships are recommended to be used whenever possible since, depending on the species, the underestimation of mass could be as much as 56%.

Community structure of aquatic insects in the Esparza River, Costa Rica

Herrera-Vásquez,Jonathan
Fonte: Revista de Biología Tropical Publicador: Revista de Biología Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2009 EN
Relevância na Pesquisa
66.65%
Community structure of aquatic insects in the Esparza River, Costa Rica. This study focused on the structure of the aquatic insect community in spatial and temporal scales in the Esparza River. The river was sampled for one full year throughout 2007. During the dry season low flow months, five sampling points were selected in two different habitats (currents and pools), with five replicates per sample site. During the wet season with peak rain, only the data in the "current habitat" were sampled at each site. Specimens present in the different substrates were collected and preserved in situ. A nested ANOVA was then applied to the data to determine richness and density as the response variables. The variations in temporal and spatial scales were analyzed using width, depth and discharge of the river, and then analyzed using a nested ANOVA. Only a correlation of 51% similarity in richness was found, while in spatial scale, richness showed significant variation between sampling sites, but not between habitats. However, the temporal scale showed significant differences between habitats. Density showed differences between sites and habitats during the dry season in the spatial scale, while in the temporal scale significant variation was found between sampling sites. Width varied between habitats during the dry season...