Dinâmica da comunidade de Copepoda (Crustacea, Maxillopoda) no lago Tupé sob a influência da enchente do Rio Negro, Manaus –AM

Abstract

In the floodplain the variation of the main river water level influences the water level of lakes adjacent to the river. The communities that inhabit these lakes suffer from this influence and are adapted to this change.The studies performed in the Amazon that have analyzed the effects of water level variation in planktonic copepods community were conducted in varzea lakes, which have different characteristics of black water lakes, these studies are limited to monthly and fortnightly collections during high and low water periods. This work’s purpose was oevaluate the effect of the Negro river (black waters) in the composition, richness and abundance of species of planktonic copepods in Tupé lake. Quantitative samples of the limnetic region, in three sampling stations in the lake were taken daily during January, February and March 2011. In the first 10 sampling days there was no influence of the river and on the 11th day of the Negro river waters begin to flood. A total of 14 taxons of copepods were recorded, (Oithona amazonica, Macrocyclops albidus albidus, Mesocyclops brasilianus, Metacyclops brauni, Thermocyclops sp., Aspinus acicularis, Rhacodiaptomus retroflexus, Rhacodiaptomus calatus, Rhacodiaptomus calamensis, Dasydiaptomus coronatus, Dactylodiaptomus pearsei, Notodiaptomus inflatus, Notodiaptomus coniferoides, Diaptomus linus). Diaptomidae was the most representative with 9 species, followed by Cyclopidae who presented four species and Oithonidae with only one representative. The specie Oithona amazonica was the most abundant throughout the study, with ist maximum abundance occurring in the lake's isolation period. The most abundant specie of Calanoida was Aspinus acicularis which also showed higher abundance in the lake's isolation period. The entrance of the Negro river waters negatively influenced the abundance of adult copepods and there was also a decrease in nauplii and copepodites density. However, the diversity and species richness increased during the rising water period.