Diel vertical migration and distribution of zooplankton in a tropical Brazilian reservoir

Biotemas

关键词: Cladocera;    Copepoda;    Rotifera;    diel migration;    semi-arid;   

DOI  :  

来源: DOAJ

【 摘 要 】

Diel vertical migration of zooplankton is a strategy usually employed to reduce the risk of predation, and it can also be associated with the environmental day/night shifts, particularly of light and temperature. The aim of this study was to identify the diel patterns of zooplankton vertical migration and their relationship to the environmental variables in a shallow reservoir in northeastern Brazil. Water samples were taken at a single five-meter depth sampling station (Subsurface, 50% Io, 1% Io and Bottom) at four-hour intervals over a period of 24 hours. Two Cladocera species (Moina minuta and Diaphanosoma spinulosum) and one Copepoda species (Notodiaptomus cearensis) showed similar patterns of nocturnal migration, staying at the bottom during the day and rising toward the surface in the afternoon and during the night. Brachionus falcatus and Hexarthra mira (Rotifera) showed no patterns of vertical migration and their vertical distributions were relatively homogenous. Environmental variables were poorly correlated to the species distribution, suggesting that other mechanisms may be responsible of inducing vertical migration.

【 授权许可】

Unknown