NICTEMERAL VARIATIONS OF THE ZOOPLANKTON IN THE UNA DO PRELADO ESTUARY, SÃO PAULO, BRAZIL Teodoro Vaske Júnior, Bruna Marques Ribeiro, Mariana Arruda Nascimento, Jéssica dos Santos Muniz Knoeller, Gabriela Alexia Simon, Andréia da Conceição Lentini Kian

Abstract

The zooplankton community of the Una do Prelado river estuary was studied according to its composition, diversity, abundance and richness, during the day and night periods in the spring of 2015. Six day and night collections were carried out with a 180 µm zooplankton net mesh, by means of horizontal trawls on the surface, at three different points in the estuary, downstream, midpoint and upstream. Fifteen large groups of organisms were identified with a remarkable predominance of the Phylum Arthropoda followed by Chaetognatha and fish. The most abundant taxon was Copepoda, followed by a notable occurrence of crustacean larvae in the zoea stage, possibly explained by the fact that the collection was carried out at a time that coincides with the reproductive period of species of the order Decapoda in the region.