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ICB - Instituto de Ciências Biológicas

URI permanente desta comunidadehttps://rihomolog.furg.br/handle/1/51

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1999 - 199912000 - 2009182010 - 201210

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Autor: search.filters.author.Albertoni, Edélti Faria

Resultados da Pesquisa

Agora exibindo 1 - 10 de 29
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    Uso de eichhornia crassipes (mart.) solms para fitorremediação de ambientes eutrofizados subtropicais no sul do Brasil
    (2012) Palma-Silva, Cleber; Albertoni, Edélti Faria; Trindade, Claudio Rossano Trindade; Furlanetto, Letícia Maria; Acosta, Michele de Carvalho
    O objetivo deste estudo foi examinar a possibilidade de uso da macrófita aquática Eichhornia crassipes (Mart.) Solms na retirada de nutrientes em lagos eutrofizados. O trabalho foi realizado na região costeira subtropical do Rio Grande do Sul, e contou com uma etapa descritiva e outra experimental. Na etapa descritiva foi feita a determinação da concentração de nutrientes da macrófita, durante um ano, em canais de escoamento pluvial. Na etapa experimental foi realizado o acompanhamento da acumulação de nutrientes na biomassa da macrófita crescendo durante 60 dias em um lago raso eutrófico. Em todas as coletas foram determinados o oxigênio dissolvido, temperatura, pH, condutividade elétrica, nitrogênio e fósforo total da água e no tecido vegetal. Foi observado que as concentrações de nutrientes na biomassa nos canais foram um pouco superiores aos valores encontrados na bibliografia, e que durante o período de crescimento experimental as concentrações de Nitrogênio e Fósforo aumentaram significativamente de 10,87 g.kg-1 para 28,50 g.kg-1, e de 3,29 g.kg-1 para 5,87 g.kg-1, respectivamente, em um período de 60 dias. Os resultados confirmam a capacidade desta espécie em acumular nutrientes rapidamente, atuando como um importante compartimento nestes ambientes. Sendo assim, apresenta grande potencial para ser utilizada em estratégias de fitorremediação de lagos eutrofizados em regiões subtropicais do Brasil.
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    Growth of immature chironomus calligraphus (diptera, chironomidae) in laboratory conditions
    (2011) Canteiro, Rita de Cássia da Silva Aloy; Albertoni, Edélti Faria
    Chironomidae larvae are important macroinvertebrates in limnic environments, but little knowledge exists about their biometrics development characteristics. This study aims to describe the immature Chironomus calligraphus Goeldi, 1905 under laboratory conditions by the accomplishment of thirteen egg masses from eggs eclosion to adults emergency, at controlled room temperature (25◦C) and photoperiod (12-12h). Larvae were feed ad libitum with “Alcon Basic – MEP 200 Complex” fish food and commercial dehydrated Spirulina. The postures had a mean length of 9 ± 1 mm (n = 13) and 348 ± 66 eggs. The brownish colored eggs with elliptical shape had length of 160.3 ± 17.7 μm (n = 130), being arranged as an organized string in a pseudo spiral form. The time duration from the first to the four instars were three, four, four and eight days, and the average length of a cephalic capsule to each one of the instars (66.3 ± 12.3 μm, 102.9 ± 22.1 μm, 159 ± 24.6 μm, 249.2 ± 29.7 μm, n = 456) were significantly different (ANOVA, p < 0.001). The Dyar’s Rule showed a constant growth rate, r = 1.5. Our results demonstrated that C. calligraphus is a species with short life cycle, low mortality rate, food adaptability, fast larval growth and easily maintained at laboratory, factors that allowed the use of this native species as a tool for ecotoxicological tests.
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    Fauna de coleóptera associada a macrófitas aquáticas em ambientes rasos do sul do Brasil
    (2011) Nascimento, Letícia Vianna do; Albertoni, Edélti Faria; Silva, Cleber Palma
    Macrófitas aquáticas são comuns e abundantes em ecossistemas aquáticos rasos, e sua presença proporciona microhabitats que podem abrigar uma alta biodiversidade de invertebrados. Entre estes, são comumente encontrados os coleópteros aquáticos. O objetivo deste estudo foi identificar os gêneros de Coleoptera associados com macrófitas aquáticas em ambientes rasos costeiros no sul do Brasil. Sete diferentes espécies de macrófitas foram coletadas entre 2001 e 2005, com uma rede (malha de 250 μm) em três tipos de ambientes: córrego arenoso (n=1), canais de escoamento pluvial (n=3) e lagos rasos (n=3). Dezoito famílias e 19 gêneros foram identificados, sendo Dytiscidae (43%) e Hydrophilidae (29%) as famílias mais abundantes. Os gêneros mais abundantes foram Hemibidessus (Dytiscidae) e Tropisternus (Hydrophilidae), presentes em todas as espécies de macrófitas aquáticas. Chrysomelidae, Curculionidae, Dryopidae (Pelonomus Erichson, 1847), Dytiscidae (Dytiscus Linnaeus, 1758), Lampyridae, Lutrochidae (Lutrochus Erichson 1848), Scarabaeidae e Staphylinidae são registrados pela primeira vez para ambientes aquáticos no estado do Rio Grande do Sul. Entre os ambientes, os lagos rasos se diferenciaram, apresentando maior riqueza, densidade e diversidade de Coleoptera. A estrutura morfológica das plantas influenciou na densidade de Coleoptera encontrada, e as macrófitas com maior sistema radicular ou presentes durante todo o ciclo anual foram as que apresentaram maior densidade e riqueza de táxons, como Pistia stratiotes, Salvinia herzogii e S. minima.
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    Temporal variation of biomass and nutrient status of azolla filiculoides lam: (sal viniaceae) in a small shallow dystrophic lake
    (2011) Trindade, Claudio Rossano Trindade; Albertoni, Edélti Faria; Palma-Silva, Cleber
    This study determined the temporal variation of the biomass and the concentrations of carbon, nitrogen and phosphorus in Azolla filiculoides Lam. in a small (0.5 ha) shallow dystrophic lake located in the city of Rio Grande (Rio Grande do Sul State, Brazil). Method: Sampling was conducted monthly between November 2000 and October 2001. The macrophytes were collected randomly in three replicates with a circular collector 0.3 m in diameter and subsequently washed with tap water and oven-dried at 60 °C for determination of the dry weight and the nutrient status (i.e., carbon, nitrogen and phosphorus). Primary productivity was estimated by the variation in biomass among successive samples. Results: A. filiculoides was present in the lake throughout the year and occupied between 50 and 80% of the surface area. The biomass values ranged from 34.2 g DW.m–2, recorded in May (autumn), to 170.9 g DW.m–2 in January (summer). The highest rate of primary productivity was 3.3 g DW.m–2.d–1, observed in June. The concentrations of carbon, nitrogen and phosphorus in the plant ranged between 403 and 551 g.kg–1, 13.4 and 25.7 g.kg–1 and 0.5 and 1.9 g.kg–1, respectively. The water N:P ratio ranged between 19:1 and 368:1. Conclusion: The coverage of the surface of the lake by A. filiculoides throughout the study period and the nutritional status of the plant demonstrate the importance of the cycling of nutrients by macrophytes in this aquatic environment. The higher N:P ratio in the water column, compared with other neighboring environments without macrophytes, shows that the enrichment of the lake may result from the biological N-fixation activity produced by A. filiculoides.
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    Aquatic macrophytes as indicators of water quality in subtropical shallow lakes, Southern Brazil
    (2012) Pereira, Sabrina Amaral; Trindade, Claudio Rossano Trindade; Albertoni, Edélti Faria; Silva, Cleber Palma
    We evaluated the potential of aquatic macrophyte communities as bioindicators in six small shallow lakes. Methods: The sampling was conducted monthly for one year, during which all macrophytes were surveyed, and the water temperature, dissolved oxygen, pH, conductivity, total alkalinity, chlorophyll-a, suspended matter, total nitrogen (Nt) and total phosphorus (Pt) were measured. Results: In total, forty-three species were recorded, and there were significant differences in the species richness and limnological conditions among the lakes studied. A canonical correspondence analysis showed that the concentration of nutrients (Nt and Pt), chlorophyll-a, suspended matter, dissolved oxygen and pH were the most important predictors of the distribution of macrophytes. Some emergents were related to the high concentration of nutrients, chlorophyll-a, and suspended matter. Moreover, the most submersed species were associated with environments with low nutrient concentrations and the lowest values chlorophyll-a and suspended matter. In addition, some species submerged and floating were related to low values pH, alkalinity and dissolved oxygen. Limnological differences between lakes may be cited as the main causes of the observed heterogeneous distribution of macrophytes. Conclusions: These results indicate the importance of limnological characteristics of the different environments in the macrophyte community composition and the potential role of this community as a bioindicator in shallow lakes in southern Brazil.
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    Aquatic macrophytes of six subtropical shallow lakes, Rio Grande, Rio Grande do Sul, Brazil
    (2012) Pereira, Sabrina Amaral; Trindade, Claudio Rossano Trindade; Albertoni, Edélti Faria; Silva, Cleber Palma
    The aim of this study was to document the richness of aquatic macrophytes in six shallow lakes at Federal University of Rio Grande - FURG, Rio Grande, Rio Grande do Sul, Brazil. Qualitative surveys were carried out during 2008. Specimens were deposited at the university herbarium (HURG). We recorded 44 species belonging to 35 genera and 21 families. The majority of species were present all year. The family with highest diversity was Cyperaceae (eight species). Other studies have reported approximately 170 species for wetlands in the south of Brazil. This study documented approximately 25% of these species. The flora of the area should be preserved and monitored.
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    Leaf degradation of salix humboldtiana willd: (salicaceae) and invertebrate colonization in a subtropical lake (Brazil)
    (2011) Telöken, Franko; Albertoni, Edélti Faria; Silva, Cleber Palma
    To evaluate leaf degradation and invertebrate colonization of Salix humboldtiana Willd. in a subtropical shallow lake on the coastal plain of Rio Grande do Sul, Brazil; Methods: Litter bags containing 6.85 g of leaves were incubated in the superficial layer of sediment in the littoral region for 1, 4, 7, 14, 32, 47 and 71 days; Results: After 71 days, a loss of 51% of the initial leaf weight was observed (k = 0.0100 d-1). We estimated that it would take 300 days to lose 95% of the initial weight. A total of 16040 organisms and 35 taxa were identified. Caenidae (25.9%), Oligochaeta (19%), Ostracoda (13.8%), Hydracarina (9.8%), Tanypodinae (9.7%) and Coenagrionidae (7.7%) were the most highly represented taxa. We observed increases in density, richness and diversity of taxa over time, with a stabilizing trend noted in the taxa diversity. Regarding the functional trophic groups (FTGs), gathering-collectors accounted for 57.6% of the community, while predators (25%), scrapers (15.8%), filtering-collectors (0.88%) and shredders (0.73%) were also represented. The diversity and evenness of the FTGs had stabilized by day 14; Conclusions: S. humboldtiana detritus provides a favorable habitat for a sufficient duration to support a high density and diversity of aquatic invertebrates. The small percentage of shredders indicates the minor influence of the invertebrate community on the rate of detrital degradation. The main contribution of invertebrates to detrital processing comes from the consumption of fine particulate organic matter by gathering-collectors.
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    Diversity of chironomidae (diptera) in decomposing nymphoides indica (l.) kuntze in two subtropical lakes with different trophic conditions
    (2010) Silva, Juliana Santos; Silveira, Wagner Terra; Albertoni, Edélti Faria; Palma-Silva, Cleber
    Chironomids are the most abundant macroinvertebrates in macrophyte detritus. The goal of this study was to characterize the diversity of these animals in decomposing Nymphoides indica and their relationship with abiotic variables and mass loss in two subtropical shallow lakes of different trophic conditions (Polegar – oligotrophic, Biguás – eutrophic). Experiments were conducted using litter bags in the summers of 2007 and 2008. Mass loss rate, total N and P concentrations of the detritus, density of chironomids (100 gDW-1), which were identified at the genera level and classified into functional trophic groups, were all recorded. The mass loss of N. indica was fast, with merely 8.5% of dried mass remaining in samples from Lake Polegar after five days and 8.7% in those from Lake Biguás after 17 days. The decay coefficient of N. indica in the oligotrophic lake, where the experiment lasted 5 days, was high (k=0.4242 d-1), as were the diversity and evenness of chironomids. In the eutrophic lake, the experiment lasted 17 days; the decay coefficient was lower (k=0.1199 d-1), as weel as diversity. The genus Goeldichironomus was the most abundant of the 13 genera found in each lake. Our results demonstrate that trophic level influences the colonization of chironomids in detritus in addition to determining the structure and ecological succession of functional trophic groups.
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    Caracterização e importância dos invertebrados de águas continentais com ênfase nos ambientes de Rio Grande
    (2010) Albertoni, Edélti Faria; Silva, Cleber Palma
    Os invertebrados aquáticos constituem um grupo de extrema importância ecossistêmica, pois apresentam uma grande biodiversidade que reúne animais de várias categorias taxonômicas, sendo essenciais na manutenção da estrutura trófica dos sistemas aquáticos. Este texto é dedicado a alunos de cursos de graduação da área biológica, e a professores de Ciências da rede de ensino fundamental e médio, tendo por objetivo fornecer uma visão geral sobre o assunto, reunindo informações da ecologia dos principais grupos, a partir de obras consagradas em ecologia de águas interiores. O formato do texto consiste principalmente de aspectos ecológicos dos grupos, apresentando exemplos de alguns organismos facilmente encontrados nos ambientes rasos da planície costeira sul do estado do Rio Grande do Sul, coletados em vários trabalhos desenvolvidos pelo laboratório de Limnologia, Instituto de Ciências Biológicas, da Universidade Federal do Rio Grande – FURG. Todos os organismos coletados encontram-se depositados na Coleção de Invertebrados Límnicos Subtropicais da universidade. Este texto tem o objetivo de fornecer uma visão geral sobre estes organismos, ressaltando sua biodiversidade e papel ecológico nos ambientes da região sul do estado do Rio Grande do Sul, bem como sua utilização como ferramenta para monitorar o estado de conservação dos ecossistemas aquáticos continentais da região.
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    Overlap of dietary niche and electivity of three shrimp species (Crustacea, Decapoda) in a tropical coastal lagoon (Rio de Janeiro, Brazil)
    (2003) Albertoni, Edélti Faria; Silva, Cleber Palma; Esteves, Francisco de Assis
    Three species of shrimp, Farfantepenaeus brasiliensis (Latreille, 1817), F. paulensis (Pérez-Farfante, 1967) (Penaeidae) and Macrobrachium acanthurus (Wiegmann, 1836) (Palaemonidae) were sampled at the Imboassica lagoon (Rio de Janeiro State, Brazil), in order to estimate the overlap of dietary niches and electivity of their prey, through the analysis of the fauna associated with the macroalgae Chara and of the benthic fauna on the sediment. The overlap of dietary niches was estimated using five indexes. A total of 495 F. brasiliensis, 131 F. paulensis and 102 M. acanthurus stomachs were examined. The results of the different indexes of niche overlap exhibited the same general trend in the three species, indicating a high degree of homogeneity in the diet of the two species of Penaeidae (between 75 and 100%) and a smaller overlap between each Penaeidae species and M. acanthurus (between 23 and 68%). The species presented selective predation, with differences in the two studied habitats. The results show that the three species are omnivorous, with a varied diet including components of benthic macrofauna and those associated with the macroalgae Chara, plant fragments and detritus, and that there are good conditions in the Imboassica lagoon for the development of these species.