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Search Results: 1 - 10 of 297487 matches for " J.;Callisto "
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Diversity of larvae of littoral Chironomidae (Diptera: Insecta) and their role as bioindicators in urban reservoirs of different trophic levels
Morais, SS.;Molozzi, J.;Viana, AL.;Viana, TH.;Callisto, M.;
Brazilian Journal of Biology , 2010, DOI: 10.1590/S1519-69842010000500011
Abstract: the chironomidae (diptera: insecta) have a high species richness, with species adapted to live under widely different environmental conditions. the study of the taxonomic composition of chironomid larvae and the percentage of occurrence of deformities in mouthparts, mainly in the mentum, are used in biomonitoring programmes in order to obtain information on the levels of organic and chemical pollution of aquatic ecosystems. the objective of this study was to evaluate the abundance of chironomid larvae and to quantify the occurrence of mentum deformities in the specimens collected in three urban reservoirs with different trophic levels. the reservoirs are located in the hydrographic basin of the paraopeba river, an affluent of the s?o francisco river basin (minas gerais state, southeastern brazil). the serra azul reservoir is oligotrophic, the vargem das flores reservoir is mesotrophic, and the ibirité reservoir is eutrophic. along the littoral zone of each reservoir, 30 samples were collected during each sampling campaign. sampling was carried out every three months for one year, with two sampling campaigns during the wet season and two during the dry season in 2008. physical and chemical parameters measured in the water column included the water depth, secchi depth, air and water temperature, electrical conductivity, total dissolved solids, redox potential, dissolved oxygen, ph, turbidity, total-n, total-p, p-ortho, and chlorophyll-a. the chironomid larvae were identified to the genus level. the structure of the chironomid assemblages was evaluated based on taxonomic richness (24 genera), density, equitability, and diversity. the potential indicator taxa for each reservoir were established through an indicator species analysis. the values for taxonomic richness (20 taxa), equitability (0.737), and shannon-wiener diversity (2.215) were highest in the serra azul reservoir. fissimentum was the indicator taxon in serra azul, the oligotrophic reservoir; whereas pelomus
Nutrient addition does not enhance leaf decomposition in a Southeastern Brazilian stream (Espinha?o mountain range)
Abelho, M.;Moretti, M.;Fran?a, J.;Callisto, M.;
Brazilian Journal of Biology , 2010, DOI: 10.1590/S1519-69842010000400007
Abstract: a decomposition experiment using eucalyptus leaves was carried out in a southeastern brazilian mountain stream located at the transition between the cerrado and the atlantic forest to test whether nutrient addition increases microbial and invertebrate colonisation and accelerates breakdown rates. the results show that none of the tested variables was significantly affected by nutrient addition, despite the average increase in atp concentrations and invertebrate colonisation observed in the fertilised leaf bags. this could mean that breakdown in the stream was already at its maximum due to the relatively high water temperature and nutrient content, or that the breakdown rate of eucalyptus leaves was too fast to allow the detection of any effects of nutrient addition. breakdown rates of eucalyptus leaves were much faster than the values reported in literature for most species in brazilian cerrado streams, suggesting that the replacement of the natural vegetation by eucalyptus may affect nutrient dynamics in the region.
Diversity and biomass of Chironomidae (Diptera) larvae in an impacted coastal lagoon in Rio de Janeiro, Brazil
Brazilian Journal of Biology , 2002, DOI: 10.1590/S1519-69842002000100010
Abstract: diversity and biomass of chironomidae larvae were studied between january-november 1993 and march-november 1994 in an impacted lagoon in rio de janeiro, southeastern brazil, in an attempt to establish the ecological consequences of anthropogenic eutrophication processes. nine hundred and seventy-five organisms belonging to the tanypodinae, orthocladiinae, and chironominae were collected. polypedilum (62%) and chironomus (58%) were the most common genera found in the limnetic and littoral zones.
Diversity and biomass of Chironomidae (Diptera) larvae in an impacted coastal lagoon in Rio de Janeiro, Brazil
Brazilian Journal of Biology , 2002,
Abstract: Diversity and biomass of Chironomidae larvae were studied between January-November 1993 and March-November 1994 in an impacted lagoon in Rio de Janeiro, Southeastern Brazil, in an attempt to establish the ecological consequences of anthropogenic eutrophication processes. Nine hundred and seventy-five organisms belonging to the Tanypodinae, Orthocladiinae, and Chironominae were collected. Polypedilum (62%) and Chironomus (58%) were the most common genera found in the limnetic and littoral zones.
Dynamics of allochthonous organic matter in a tropical Brazilian headstream
Gon?alves Júnior, José Francisco;Fran?a, Juliana Silva;Callisto, Marcos;
Brazilian Archives of Biology and Technology , 2006, DOI: 10.1590/S1516-89132006000700014
Abstract: the species composition of the riparian vegetation and the seasonal contribution of input and storage of fine and coarse particulate organic matter were assessed in a 3rd order stretch. fourteen tree species in the riparian zone were identified, with 3 species contributing with 68% of total litter input: miconia chartacea triana (43%), miconia cyathanthera triana (16%) and erythroxylum pelletarianum st. hil (9%). the allochthonous input of coarse particulate organic matter (cpom) was composed mainly by leaves (over 50%). species composition and the contribution of each plant species biomass for vertical, lateral and soil inputs and benthic stocks varied along the study period. the maximum values found in september, november and december coincided with the beginning of the rainy season. there were no differences between the allochthonous vertical and lateral inputs of cpom to the stream. differently to other studies, this result was probably due to the peculiar composition of stream?s riparian vegetation at serra do cipó.
Malacological assessment and natural infestation of Biomphalaria straminea (Dunker, 1848) by Schistosoma mansoni (Sambon, 1907) and Chaetogaster limnaei (K. von Baer, 1827) in an urban eutrophic watershed
Callisto, M.;Moreno, P.;Gon?alves, J. F. Jr.;Ferreira, W. R.;Gomes, C. L. Z.;
Brazilian Journal of Biology , 2005, DOI: 10.1590/S1519-69842005000200005
Abstract: the objective of this study was to perform a malacological assessment at the ibirité reservoir watershed in the metropolitan region of belo horizonte (minas gerais) and to evaluate the natural infestation rate of biomphalaria straminea (gastropoda: planorbidae)by schistosoma mansoni (platyhelminthes: trematoda) and chaetogaster limnaei (oligochaeta: naididae). the samples were collected from july to august 2002. the b. straminea individuals collected were kept in the laboratory; the natural infestation rate by s. mansoni and c. limnaei was assessed weekly. the malacological assessment identified fivemollusk species present in the ibirité reservoir watershed: b. straminea, physa marmorata, lymnea sp., melanoides tuberculatus,and pomacea austrum. laboratory observations showed that the b. straminea individuals were infected by c. limnaei rather than s. mansoni. although there was no infection of b. straminea by s. mansoni,presence of b. straminea in itself merits close attention due to possible risk of human schistosomiasis by the local population.
Of rapid assessment approach to discuss ecological theories in wetland systems, Southern Brazil
Maltchik,Leonardo; Callisto,Marcos;
Interciencia , 2004,
Abstract: the rapid assessment program (rap) constitutes a powerful tool used to select important areas for the conservation of biodiversity. the relationships between species diversity and the ecosystem size have been investigated by biologists, mainly in terrestrial ecosystems. recent biodiversity surveys of algae, macrophytes and macroinvertebrates were developed in the sinos river basin (southern brazil) using the aqua-rap approach as a tool. the selection of wetlands (different size and classes) was fundamental to discuss the relationship between biodiversity and the size of ecosystems. only macrophyte richness was positively correlated to the size of the wetland. the richness of algae and macroinvertebrates was not influenced by the size of the wetlands. these results show the importance of the inclusion of different biological communities to test ecological theories and to propose strategies for conservation programs.
Benthic macroinvertebrates as bioindicators of water quality in an Atlantic forest fragment
Oliveira, Augusto;Callisto, Marcos;
Iheringia. Série Zoologia , 2010, DOI: 10.1590/S0073-47212010000400003
Abstract: the objective of this study was to evaluate benthic macroinvertebrate communities as bioindicators of water quality in five streams located in the "reserva particular do patrim?nio natural" (rppn) mata samuel de paula and its surroundings, in the municipality of nova lima near the city of belo horizonte, minas gerais state, southeastern brazil. this region has been strongly modified by human activities including mining and urbanization. samples were collected in the field every three months between august 2004 and november 2005, totaling six samplings in the rainy and dry seasons. this assessment identified one area ecologically altered while the other sampling sites were found to be minimally disturbed systems, with well-preserved ecological conditions. however, according to the biological monitoring work party (bmwp) and the average score per taxon (aspt) indices, all sampling sites had excellent water quality. a total of 14,952 organisms was collected, belonging to 155 taxa (148 insecta, two annelida, one bivalvia, one decapoda, one planariidae, one hydracarina, and one entognatha). the most abundant benthic groups were chironomidae (47.9%), simuliidae (12.3%), bivalvia (7.5%), decapoda (6.1%), oligochaeta (5.2%), polycentropodidae (3.7%), hydropsychidae (2.5%), calamoceratidae (1.8%), ceratopogonidae (1.7%), and libellulidae (1.2%). the assessment of the benthic functional feeding groups showed that 34% of the macroinvertebrates were collector-gatherers, 29% predators, 24% collector-filterers, 8% shredders, and 5% scrapers. the rppn mata samuel de paula comprises diversified freshwater habitats that are of great importance for the conservation of many benthic taxa that are intolerant to organic pollution.
Mayfly diversity in the brazilian tropical headwaters of Serra do Cipó
Goulart, Michael;Callisto, Marcos;
Brazilian Archives of Biology and Technology , 2005, DOI: 10.1590/S1516-89132005000800015
Abstract: the objectives of this study were to evaluate spatial and seasonal distribution, assemblage structure and substrate associations of mayfly nymphs in five lotic ecosystems in the headwaters of the doce river and s?o francisco river watersheds, brazil. samples were taken in 24 sampling stations during rainy and dry seasons in 1998. in total, 7,066 organisms were collected, belonging to 27 genera and 6 families of ephemeroptera. the dominant taxa were americabaetis, paracloeodes, leptohyphes and hagenulus. during the rainy period, the s?o francisco river watershed showed higher taxonomic richness, diversity and evenness, while in the dry period, the taxonomic richness was higher in doce river watershed. no significant differences were found in the taxonomic richness, diversity, evenness and density of mayfly assemblages between the two studied sampling periods. the results suggested that the diversity of the mayfly assemblages in tropical headwaters of serra do cipó would be probably due to ecosystem and watershed characteristics.
Macroinvertebrates as tadpole food: importance and body size relationships
Dutra, Silvia L.;Callisto, Marcos;
Revista Brasileira de Zoologia , 2005, DOI: 10.1590/S0101-81752005000400018
Abstract: macroinvertebrates as food were recorded for three anurans tadpoles: hyla saxicola (bokermann, 1964) (hylidae), scinax machadoi (bokermann & sazima, 1973) (hylidae), and bufo rubescens (lutz, 1925) (bufonidae). these species are commonly found in the mountain streams at serra do cipó national park, minas gerais state, brazil. tadpoles were collected in pools of second-order reach in mascates stream and third and fourth order reaches of indaiá stream from march-october, 2003. biometrical data were recorded before dissecting each individual and a feeding importance index was estimated. eight taxa of chironomids and three taxa of mayfly exuviae were found in the guts, but no significantly differences were found between tadpole species (anova, p > 0.05). the results support the drift transport hypothesis that predicts that tadpoles commonly ingest suspended matter in lotic ecosystems, are generalist feeders, and macroinvertebrates are probably incidental ingested.
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