Diversidade, densidade e biomassa instantânea em lagoas e ambientes litorâneos da planície de inundação do alto rio Paraná

Abstract

Fish assemblages from five environments of the upper Paraná river floodplain with distinct physical-chemical and structural features are compared. Samples were collected using three seine nets simultaneously, with same characteristics, covering an area of 428 m2 and employing the removal fishing technique. To estimate density and standing crop, the maximum likelihood estimate method was used. Inferences in speciphic diversity was obtained by Shannon and Simpson indexes. Environments clustering using chemical-physical and structural features were consistents with the previous classification in lagoons and littoral zone. Habitats with same features presented similar biomass. The exclusive occurence of juveniles of the seven among ten large migratory species showed the great importance of the lagoons to the early develpment of this species in this region.