LEVANTAMENTO COMPARATIVO DE ZOOPLÂNCTON EM ÁREA DE PRODUÇÃO DE PEIXES E EM ÁREA NÃO OCUPADA POR SISTEMAS DE PRODUÇÃO DO RIO PARANÁ (SANTA FÉ DO SUL - SP / RUBINÉIA - SP)

The use of aquatic ecosystems for leisure purposes, dilution of liquid waste and production promote negative interferences that alter the local biota. Zooplankton surveys allow the rapid detection of environmental changes, as aquatic pollution creates a selective environment, causing changes in the abundance and composition of zooplankton communities, which respond rapidly to changes in the environment, due to their short life cycle. The study aimed at inventorying and comparing the zooplankton community in two distinct areas of the Paraná River, one area of fish production and other not occupied. The collections were carried out, monthly, with the aid of plankton net of 68 μm. The samples obtained were anesthetized and stored in labeled bottles. The physical and chemical parameters of the water, such as pH, transparency and the level of turbidity were measured. The identification of the microorganisms was performed under an optical microscope, using specific keys. Copepoda, Cladocera and Rotifera were observed in both areas. In the production area, Copepoda: Diaptomus and Cyclops, Cladocera; Alona, Camptocercus, Ceriodaphinia, Diaphanosoma, Dunhevediae Simocephalus were found. And the Rotifera variety was shown in Philodina, Conochilus, Ascomorpha, Otostephanos, Mytilina, Collotheca, and Keratella. In the unoccupied area, Copepoda Acartia, Diaptomus, Labidocera and Cyclops were observed. Cladocera Alona, Ceriodaphinia, Bosmina and Daphnia and Rotifera only Ptygura were identified. It was verified that the environmental conditions of the studied sites vary naturally, but the anthropic action also encourages such variations, which interferes in the structure of the zooplankton communities. However, it would be unfeasible to diagnose the degree of trophicness of the ecosystems.