Brazilian Journal of Biology | |
Fluctuations of the population of Daphnia laevis Birge 1878: a six-year study in a tropical lake | |
Lpm. Brandão2  T. Fajardo2  E. Eskinazi-sant'anna1  S. Brito2  P. Maia-barbosa2  | |
[1] ,Universidade Federal de Minas Gerais Instituto de Ciências Biológicas Belo Horizonte MG ,Brazil | |
关键词: Daphnia laevis; Brazil; tropical lake; temperature; ephippium; Daphnia laevis; Brasil; lago tropical; temperatura; efípio; | |
DOI : 10.1590/S1519-69842012000300010 | |
来源: SciELO | |
【 摘 要 】
The fluctuation of the population of Daphnia laevis in Lake Jacaré (Middle River Doce, Minas Gerais) was monitored monthly (at one point in the limnetic region) for six years (2002-2007) as part of the Program of Long-Term Ecological Research (LTER/UFMG). The following parameters were also monitored: water temperature, pH, electrical conductivity, dissolved oxygen, chlorophyll a, total phosphorus, phosphate, total nitrogen, nitrate, nitrite, ammonia, and densities of Chaoborus and ephippia of Daphnia laevis in the sediment. A seasonal pattern was observed in the fluctuation of D. laevis, with higher densities recorded during periods of circulation (May-August). A significant correlation was found between the density of D. laevis and temperature (r = -0.47, p = 0.0001), chlorophyll-a (r = -0.32, p = 0.016) and indicators of the lake's trophic status (total phosphorus, r = 0.32, p = 0.007 and trophic state, r = 0.36, p = 0.003), as well as Chaoborus density (r = 0.43 and p = 0.002). These results indicate that changes in the physical and chemical characteristics of the water related with stratification and circulation of the lake may have a direct (temperature, total phosphorous) or an indirect (food availability, presence of predators, ephippia eclosion) influence on the fluctuation of the D. laevis population.
【 授权许可】
CC BY
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