RESUMO
This study evaluated the spatial variations in species richness and abundance of zooplankton over a hydrological cycle, and also verified the influence of physical and chemical water variables and chlorophyll-a concentrations on the abundance of these organisms. The tested hypothesis was that the zooplankton community presents higher species richness in lotic environments and higher abundance in lentic ones. One hundred forty species were identified, distributed among rotifers (88), testate amoebae (35), cladocerans (13) and copepods (4). Higher values of species richness and abundance were observed during the dry period. During both hydrological periods, the copepods presented high abundance values, due to the contribution of young stages, followed by rotifers, cladocerans and testate amoebae. In general, testate amoebae presented high values of species richness and abundance in lotic sampling stations, whereas the other zooplankton groups (rotifers, cladocerans and copepods) presented higher abundances in lentic environments and higher species richness in lotic ones. The Pearson correlation analysis evidenced the importance of physical and chemical water variables and food resource availability influencing the variation of organisms abundance.
This study evaluated the spatial variations in species richness and abundance of zooplankton over a hydrological cycle, and also verified the influence of physical and chemical water variables and chlorophyll- concentrations on the abundance of these organisms. The tested hypothesis was that the zooplankton community presents higher species richness in lotic environments and higher abundance in lentic ones. One hundred forty species were identified, distributed among rotifers (88), testate amoebae (35), cladocerans (13) and copepods (4). Higher values of species richness and abundance were observed during the dry period. During both hydrological periods, the copepods presented high abundance values, due to the contribution of young stages, followed by rotifers, cladocerans and testate amoebae. In general, testate amoebae presented high values of species richness and abundance in lotic sampling stations, whereas the other zooplankton groups (rotifers, cladocerans and copepods) presented higher abundances in lentic environments and higher species richness in lotic ones. The Pearson correlation analysis evidenced the importance of physical and chemical water variables and food resource availability influencing the variation of organisms abundance.
RESUMO
This study evaluated the spatial variations in species richness and abundance of zooplankton over a hydrological cycle, and also verified the influence of physical and chemical water variables and chlorophyll-a concentrations on the abundance of these organisms. The tested hypothesis was that the zooplankton community presents higher species richness in lotic environments and higher abundance in lentic ones. One hundred forty species were identified, distributed among rotifers (88), testate amoebae (35), cladocerans (13) and copepods (4). Higher values of species richness and abundance were observed during the dry period. During both hydrological periods, the copepods presented high abundance values, due to the contribution of young stages, followed by rotifers, cladocerans and testate amoebae. In general, testate amoebae presented high values of species richness and abundance in lotic sampling stations, whereas the other zooplankton groups (rotifers, cladocerans and copepods) presented higher abundances in lentic environments and higher species richness in lotic ones. The Pearson correlation analysis evidenced the importance of physical and chemical water variables and food resource availability influencing the variation of organisms abundance.
This study evaluated the spatial variations in species richness and abundance of zooplankton over a hydrological cycle, and also verified the influence of physical and chemical water variables and chlorophyll- concentrations on the abundance of these organisms. The tested hypothesis was that the zooplankton community presents higher species richness in lotic environments and higher abundance in lentic ones. One hundred forty species were identified, distributed among rotifers (88), testate amoebae (35), cladocerans (13) and copepods (4). Higher values of species richness and abundance were observed during the dry period. During both hydrological periods, the copepods presented high abundance values, due to the contribution of young stages, followed by rotifers, cladocerans and testate amoebae. In general, testate amoebae presented high values of species richness and abundance in lotic sampling stations, whereas the other zooplankton groups (rotifers, cladocerans and copepods) presented higher abundances in lentic environments and higher species richness in lotic ones. The Pearson correlation analysis evidenced the importance of physical and chemical water variables and food resource availability influencing the variation of organisms abundance.
RESUMO
This paper intends to be a contribution on the occurrence and geographical distribution of testate amoebae (Protozoa, Amoebozoa, Rhizopoda) in Brazilian inland waters, specifically the families Hyalospheniidae, Plagiopyxidae, Microcoryciidae, Cryptodifflugiidae, Phryganelidae, Euglyphidae, Trinematiidae and Cyphoderiidae. Fifty-four infra-generic taxa have been recorded. The genera with the greatest number of taxa are Nebela (Hyalospheniidae), with 17 taxa, and Euglypha (Euglyphidae), with 14 taxa. Euglypha acantophora (Ehrenberg), E. cristata Leidy, E. laevis (Ehrenberg), E. strigosa (Ehrenberg), Trinema enchelys (Ehrenberg), T. lineare Pénard and Cyphoderia ampulla (Ehrenberg) are the species with the greatest number of records in Brazil. Some taxonomic information is also provided
Este trabalho tem o objetivo de contribuir para o conhecimento sobre a ocorrência e distribuição geográfica de tecamebas (Protozoa, Amoebozoa, Rhizopoda) em ambientes aquáticos continentais brasileiros, especificamente das famílias Hyalospheniidae, Plagiopyxidae, Microcoryciidae, Cryptodifflugiidae, Phryganelidae, Euglyphidae, Trinematiidae e Cyphoderiidae. Foi registrado um total de 54 táxons infragenéricos. Os gêneros com maior número de táxons são Nebela (Hyalospheniidae), com 17 táxons, e Euglypha (Euglyphidae), com 14 táxons. Euglypha acantophora (Ehrenberg), E. cristata Leidy, E. laevis (Ehrenberg), E. strigosa (Ehrenberg), Trinema enchelys (Ehrenberg), T. lineare Pénard e Cyphoderia ampulla (Ehrenberg) são as espécies com maior número de registros no Brasil. Algumas informações taxonômicas são fornecidas
RESUMO
Among the testate amoebae the genus Difflugia contains the largest number of species, comprising about three hundred named species, varieties and forms. Testate amoebae fauna, more intensively studied in recent years in Brazil, hailed from a variety of different habitats such as sediments, aquatic macrophytes and the plankton. However, these studies have been limited to few geographic regions. In this study we furnish current information on the geographic distribution and occurrence of the species of genus Difflugia in Brazilian inland waters. Taxonomic information is also provided. A total of 60 infra-generic taxa is listed, among which Difflugia corona Wallich, D. lobostoma Leidy, D. oblonga Ehrenberg, D. urceolata Carter and D. acuminate Ehrenberg are the most frequent and the most widespread in freshwater environments in Brazil
Entre as tecamebas, o gênero Difflugia apresenta o maior número de espécies, com aproximadamente 300 espécies, variedades e formas descritas. No Brasil, a fauna de tecamebas, proveniente de diferentes hábitats, como sedimento,macrófitas aquáticas e plânton, tem sido mais intensivamente estudada nos últimos anos. No entanto, essas pesquisas estão limitadas a poucas regiões geográficas. Neste estudo,são fornecidas informações sobre a distribuição geográfica e a ocorrência das espécies do gênero Difflugia no Brasil. Informações taxonômicas atualizadas são fornecidas. É apresentado um total de 60 táxons infragenéricos, dentre os quais Difflugia corona Wallich, D. lobostoma Leidy, D. oblonga Ehrenberg, D. urceolata Carter and D. acuminata Ehrenberg são os que apresentam maior freqüência de ocorrência e os mais amplamente distribuídos nos sistemas de água doce brasileiros
RESUMO
Among the testate amoebae the genus Difflugia contains the largest number of species, comprising about three hundred named species, varieties and forms. Testate amoebae fauna, more intensively studied in recent years in Brazil, hailed from a variety of different habitats such as sediments, aquatic macrophytes and the plankton. However, these studies have been limited to few geographic regions. In this study we furnish current information on the geographic distribution and occurrence of the species of genus Difflugia in Brazilian inland waters. Taxonomic information is also provided. A total of 60 infra-generic taxa is listed, among which Difflugia corona Wallich, D. lobostoma Leidy, D. oblonga Ehrenberg, D. urceolata Carter and D. acuminate Ehrenberg are the most frequent and the most widespread in freshwater environments in Brazil
Entre as tecamebas, o gênero Difflugia apresenta o maior número de espécies, com aproximadamente 300 espécies, variedades e formas descritas. No Brasil, a fauna de tecamebas, proveniente de diferentes hábitats, como sedimento,macrófitas aquáticas e plânton, tem sido mais intensivamente estudada nos últimos anos. No entanto, essas pesquisas estão limitadas a poucas regiões geográficas. Neste estudo,são fornecidas informações sobre a distribuição geográfica e a ocorrência das espécies do gênero Difflugia no Brasil. Informações taxonômicas atualizadas são fornecidas. É apresentado um total de 60 táxons infragenéricos, dentre os quais Difflugia corona Wallich, D. lobostoma Leidy, D. oblonga Ehrenberg, D. urceolata Carter and D. acuminata Ehrenberg são os que apresentam maior freqüência de ocorrência e os mais amplamente distribuídos nos sistemas de água doce brasileiros
RESUMO
This paper intends to be a contribution on the occurrence and geographical distribution of testate amoebae (Protozoa, Amoebozoa, Rhizopoda) in Brazilian inland waters, specifically the families Hyalospheniidae, Plagiopyxidae, Microcoryciidae, Cryptodifflugiidae, Phryganelidae, Euglyphidae, Trinematiidae and Cyphoderiidae. Fifty-four infra-generic taxa have been recorded. The genera with the greatest number of taxa are Nebela (Hyalospheniidae), with 17 taxa, and Euglypha (Euglyphidae), with 14 taxa. Euglypha acantophora (Ehrenberg), E. cristata Leidy, E. laevis (Ehrenberg), E. strigosa (Ehrenberg), Trinema enchelys (Ehrenberg), T. lineare Pénard and Cyphoderia ampulla (Ehrenberg) are the species with the greatest number of records in Brazil. Some taxonomic information is also provided
Este trabalho tem o objetivo de contribuir para o conhecimento sobre a ocorrência e distribuição geográfica de tecamebas (Protozoa, Amoebozoa, Rhizopoda) em ambientes aquáticos continentais brasileiros, especificamente das famílias Hyalospheniidae, Plagiopyxidae, Microcoryciidae, Cryptodifflugiidae, Phryganelidae, Euglyphidae, Trinematiidae e Cyphoderiidae. Foi registrado um total de 54 táxons infragenéricos. Os gêneros com maior número de táxons são Nebela (Hyalospheniidae), com 17 táxons, e Euglypha (Euglyphidae), com 14 táxons. Euglypha acantophora (Ehrenberg), E. cristata Leidy, E. laevis (Ehrenberg), E. strigosa (Ehrenberg), Trinema enchelys (Ehrenberg), T. lineare Pénard e Cyphoderia ampulla (Ehrenberg) são as espécies com maior número de registros no Brasil. Algumas informações taxonômicas são fornecidas