Fitoplâncton como alimento para microcrustáceos e rotíferos nos períodos de seca e enchente no lago Tupé, Manaus-AM
The lake Tupé, which is located near Manaus, in the Amazonas state, is a black-water lake of great richness of phytoplanktonic and zooplanktonic species. The zooplanktonic organisms may belong to different size categories: microplankton, mesoplankton, and macroplankton; but the phytoplanktonic or...
| Autor principal: | Mendes, Raize Castro |
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| Grau: | Dissertação |
| Idioma: | por |
| Publicado em: |
Instituto Nacional de Pesquisas da Amazônia - INPA
2020
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| Assuntos: | |
| Acesso em linha: |
https://repositorio.inpa.gov.br/handle/1/11369 http://lattes.cnpq.br/5664226512014558 |
| Resumo: |
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The lake Tupé, which is located near Manaus, in the Amazonas state, is a black-water
lake of great richness of phytoplanktonic and zooplanktonic species. The zooplanktonic
organisms may belong to different size categories: microplankton, mesoplankton, and
macroplankton; but the phytoplanktonic organisms may belong to picoplankton,
nanoplankton, and microplankton. Because of the size difference, the zooplanktonic
organisms might be feeding on phytoplanktonic organisms of different sizes. The goal of
this research was to evaluate the importance of phytoplankton different fractions as food
for microcrustaceans and planktonic rotifers in the low waters period (2015) and rising
waters (2016) at the lake Tupé, Manaus-AM. The samples were conducted in two months
at the low Waters period and two months in the rising Waters period at the lake Tupé
(Reserve of Sustainable Development of Tupé). As sampling criteria, the estimated photic
zone extension was used with the assistance of transparency measures by the Secchi disc.
A PVC tube of 50 mm in diameter and 3 m in length with a water retention valve which
was inserted in this extension and its content was placed in a bucket, homogenized and 2
L samples were taken. At the laboratory, the samples were fractionated in order to obtain
the picoplankton, nanoplankton, and microplankton and later the biomass of each fraction
was measured through the Chlorophyl-a. An experiment was placed at lake Tupé during
24 hours in the low Waters period and rising water period. The zooplanktonic and
phytoplanktonic samples were collected with a PVC tube of 4 m in length, later they were
taken to the laboratory to be analyzed. The zooplanktonic organisms. The zooplanktonic
organisms were counted and measured. The phytoplankton samples were fractionated in
order to obtain the differences in size fraction, and later, the biomass of each fraction was
measured. The total low Waters period biomass was 27,03 μg/L, and the total rising
Waters biomass was 36,59 μg ̸ L. There were no statistically significant differences
between the biomass of the picoplankton, nanoplankton and microplankton in the two
periods. The zooplanktonic organisms did not exercised selective predation pressure on
just one of the phytoplankton size fractions. Instead, they exercised predation pressure on
phytoplankton three size fractions. |