Invertebrados zooplanctônicos em dois brejos de altitude da Paraíba

Abstract

In this study we feature the big groups of zooplankton invertebrates in the localities of swamp in Areia and Natuba, cities in the Paraíba state, Brasil. Two collections were made for each location: one in April and another in November in Areia, at the Vaca Brava reservoir; and in March and November in Natuba, at the city's reservoir. Four collecting points were determined in each environment. Zooplankton organisms were collected using a 50 µm zooplankton net, filtring 200 liters of water from the littoral zone of the reservoirs and fixed with 4% formalin. Environmental abiotic data were also collected, namely: water temperature, pH, redox potential, conductivity, dissolved oxygen and total dissolved solids. 1 L of water was collected for nutrient analysis (ammonia, nitrite, nitrate and phosphate). In the laboratory, the zooplankton samples were counted using a 1 mL Sedgwick-rafter chamber. The density (ind.L-1) and abundance of the groups was calculated. In Areia, Rotifera predominated in the dry season (87%), with the absence of other groups in this season. In the city of Natuba, copepods stand out with an abundance of 86% during the flood season, which is equivalent to 97.4 ind.L-1. Mann-Whitney test was performed correlating groups with location and season. Significant results were found for Cladocera and i nsect l arvae in relation to the season; and for r otifers in relation to the location. The concentrations of nutrients were, for the most part, within the limits of CONAMA resolution 357/05 for the Class 2, as well as the abiotic data also did not present worrying results.