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The effect of water transparency, dissolved oxygen concentration and the invertebrate predator Chaoborus
brasiliensis on the day–night vertical distribution of the copepod cyclopoid Thermocyclops inversus was investigated in a shallow tropical reservoir, Nado Reservoir, Belo Horizonte, Brazil. Diel cycles were carried out over
a period of 12 consecutive months, between October 1999 and September 2000. The different developmental stages of T. inversus exhibited diel vertical migration (DVM) and displayed a clear ontogenetic trend, with the amplitude of DVM increasing with
the age of the organism, and ranging from 0.4 m to 0.8 m for nauplii, 0.4 m to 1.2 m for copepodite, and 1.1 m to 2.1 m for
adults. We observed that seasonal changes in dissolved oxygen and C. brasiliensis directly influenced the vertical distribution of the copepod population in this reservoir. Furthermore, it was showed that
the diurnal vertical migration is an important predator avoidance behavior since it diminished the spatial overlap between
prey and its potential predator. This finding supports the hypothesis that the vertical migration is a defense mechanism against
predation. Thus, T. inversus is able to remain in the anoxic layers during day light hours, and at night they move upwards avoiding hypolimnetic waters
to escape from predation by Chaoborus. 相似文献
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This is a long-term study (1993-1998) on the effects of increasing eutrophication on the crustacean zooplankton structure in a eutrophic reservoir. The study first demonstrates that the eutrophication increase verified is a phenomenon well described by a single abiotic variable: total phosphorus. During the study period, zooplankton suffered extensive qualitative and quantitative changes. Significant size and biomass responses of certain zooplankton groups to the temporal variations of total phosphorus were found. These findings suggest that the variables size and biomass of major zooplankton groups should always be considered simultaneously in order to assess impacts caused by eutrophication on the structure of zooplankton. 相似文献
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R M Pinto-Coelho A Giani C A Morais-Jr E R Carvalho-Jr J F Bezerra-Neto 《Revista brasleira de biologia》2005,65(2):313-324
The temporal variability of energetic reserves of zooplankton in the eutrophic Pampulha reservoir was investigated during two successive annual cycles. The effects of dominance of large filter-feeding cladocerans (Daphnia) and the occurrence of massive blooms of the cyanobacteria Microcystis on the energetic reserves of zooplankton were tested. This study showed that phytoplankton composition has a greater effect on energetic reserves of zooplankton. Some associations between lipid levels and the specific composition of zooplankton were also found. This study also demonstrated that the elementary composition of phosphorus in zooplankton can be used as an estimator of the nutritional status of zooplankton. 相似文献
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Jovem-Azevêdo Daniele Bezerra-Neto José Fernandes Feio Maria João Fernandes Rodrigo Gomes Wilma Izabelly Ananias Thomaz Sidinei Magela Molozzi Joseline 《Hydrobiologia》2022,849(3):625-639
Hydrobiologia - This study aimed to investigate the relative importance of abiotic factors and biotic resistance (expressed as species richness of native macroinvertebrates), through a correlative... 相似文献
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Brando Luciana Pena Mello Staehr Peter Anton Brighenti Ludmila Silva Peifer Daniel Barbosa Francisco Antnio Rodrigues Bezerra-Neto Jos Fernandes 《Limnology》2022,23(1):207-217
Limnology - Dissolved organic matter (DOM) is a central driver of many processes in aquatic environments. Here, we address the issue of spatial and temporal variations in DOM quantity and quality... 相似文献
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Gagliardi Laura Martins Brighenti Ludmila Silva Staehr Peter Anton Barbosa Francisco Antônio Rodrigues Bezerra-Neto José Fernandes 《Ecosystems》2019,22(6):1406-1423
Ecosystems - Ecosystem-level metabolism is a good sentinel for human and natural disturbances in freshwater systems, responding from local changes (for example, land use) to regional and global... 相似文献
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