Composition of zooplankton of the small river Jesumira, located in a cleared in area at the Park National Serra do Divisor, State of Acre, Brazil

Abstract

The Upper Juruá is rich in biodiversity, not only because it is located at an untouched region, but also because it is near the equator, it is part of wealth in the tropics. Ecosystems in the region, however, have been modified by humans, what has resulted in biodiversity loss. The zooplankton is very vulnerable to environmental perturbations. This work aimed to study zooplankton taxonomy, and to address some ecological issues. The Jesumira Igarapé is located at the Parque Nacional da Serra do Divisor, between coordinates 7° 28’10, 2 “S and 73 º 33’54, 6” W. Quantitative sampling was conducted with a 55?m mesh size plankton net.  Horizontal and vertical hauls were performed, totaling eight samplings in the littoral and pelagic zones, at low and high tides. Analysis of zooplankton samples were conducted using a micro camera attached to a DCE microscope whose image was projected onto an Acer laptop with software installed to capture images and photos for species identification. The limnological variables obtained were as follows: temperature 24.17oC ± 2.19 (pelagic) and 24.01 oC ± 2.20 (littoral); pH 6.50 ± 0.37 (pelagic) and 6.42 ± 0.28 (littoral); dissolved oxygen 8.61 mg.L-1 ± 0.65 e e 8,00±0,32 mg.L-1; turbidity 39.50 UNT±7,14 (pelagic) and 27.86 TNU ±11,84 (littoral); transparency 0.26 m ±14.84  (pelagic) and 0.55±10.90 (littoral) and depth 0.31m ±0.21 (pelagic) and 0.73m ±0.11 (littoral). With respect to diversity, 30 species of rotifers, one species of Cladocera, immature stages of copepods, arthropod larvae (especially representatives of the abundant class Insecta) were listed.  Another relevant result of this study was the finding of thirthy and two new records for the state of Acre.