INFLUENCE OF UPWELLING AND TROPICAL ENVIRONMENTS ON THE BREEDING DEVELOPMENT OF THE INTERTIDAL BARNACLE

Cabo Frio, with its unique oceanographic conditions, is an important biogeographical transitional region between tropical and sub-tropical waters. This is due to the presence of upwelling from the Central Water of the South Atlantic (CWSA), and the presence of tropical waters from the Brazilian Current (BC) and Coastal Water (CW). The intertidal barnacle, Tetraclita stalactifera, and its brooding stages were analyzed to correlate environmental conditions with reproductive development. Two thermal contrasting sites were chosen: Ponta da Cabeca (PC), which is under the influence of seasonal upwelling, and Ponta da Fortaleza (PF) which experiences tropical influences. At each site, T. stalactifera specimens were collected monthly and their egg lamellae conditions classified into stages from 0 (empty) to IV (ready to release). Our results show a seasonal effect on brooding at the PC site and a continuous development at the PF site. Nauplii larval availability also followed this trend. Differences between the sites could be due to ecological differences related to water temperature and the ecological-physiological response of the barnacles to these differences.