Eclosão in situ de formas dormentes de microcrustáceos e rotíferos de um lago de água preta da Amazônia

Abstract

The objective of the study was to determine if the hatching abundance of dormant forms of Cladocera, Copepoda and Rotifera vary in different light intensities and different flood times according to the variation of the water level. For this we test the following hypotheses: i) greater light intensity results in greater hatching abundance; (ii) the hatching abundance of dormant forms decreases with increasing flood time on the litter and non-litter banks. In situ experiments were carried out with sediments from Lake Tupé, Manaus-AM, Brazil. Three light conditions were tested, being 100, 50 and 1%, and the number of hatching at different flood times of sediment of the ATTZ with and without litter was verified that pass for a time without water. It was possible to verify that hatching of the dormant forms of the three groups occurs independently of the light intensity that reaches the sediment, since the different intensities will only influence the amount of egg that breaks out in each region. We also observed that the hatching of dormant forms present on the banks with and without litter increases concomitantly with the increase of the water column in the flood period. With this, it was possible to determine the variation of the abundance in the different light intensities and in the different times of flood.