Biotemas (Sep 2012)
Thecamoebians: occurrence and distribution in Iguape Bay/BTS – Bahia, Brazil
Abstract
The Iguape Bay (12º00’ – 13º00’S and 38º30’ – 39º30’) is an estuary located at the mouth of the Paraguaçu River, inside Todos os Santos Bay (BTS), in Bahia, Brazil. It is 30km downstream from the Pedra do Cavalo Dam, which is the second largest dam in Brazil. The water in Iguape Bay is influenced by ocean tides originating from the BTS and the discharge of the Paraguaçu River. The effects of the currents as well as the variation in the outflow from the Pedra do Cavalo Dam have intensified the natural stress of this paralic environment. The main goal of this study was to investigate the distribution of Thecamoeba species present in the bottom sediments of Iguape Bay, in order to produce data that can be used to interpret the processes operating in this ecologically complex environment. The density of the living and dead species of Thecamoeba was determined by the volume of sediment collected, and the diversity index, constancy, evenness and richness of Thecamoeba were calculated. Sedimentological analyses were also performed in order to classify sediment types in the selected profiles.
