Experimental assessment of the lethal and non-lethal effects of benthic predators with different feeding strategies, Eriphia gonagra e Thais haemastoma, on the bivalve Perna perna

• Grant number: 09/07678-7
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: December 01, 2009
• End date: January 31, 2014
• Field of knowledge: Biological Sciences - Ecology
• Principal Investigator: Augusto Alberto Valero Flores
• Grantee: María Soledad López
• Host Institution: Centro de Biologia Marinha (CEBIMAR). Universidade de São Paulo (USP). São Sebastião , SP, Brazil
• Associated scholarship(s): 12/03650-3 - Risk allocation hypotheses and trophic cascades: the effect of variable risk predation environments on the feeding behavior of the herbivorous Littorina obtusata and the induced defenses of the macroalgae Ascophyllum nodosum, BE.EP.PD

Abstract

Most studies addressing predation in rocky shores have emphasized lethal effects (consumption) of predators on prey density. Non-lethal effects, such as the development of defensive morphological and behavioral features induced by predation risk, and their indirect role in other trophic levels, is recently gaining increasing attention. In Brazil, little is known on the effect of predation in community structure. In this project, the effect of different benthic predators will be examined on the edible mussel Perna perna, which is a species of commercial interest in the region. Laboratory experiments were designed to identify induced morphological defenses in sessile prey by two benthic predators using different predation mechanisms, the crab Eriphia gonagra and the whelk Thais haemastoma. In the field, non-lethal indirect effects of predators on prey density will be evaluated. By monitoring the natural community, including the quantification of predator abundance, prey cover and their recruitment, we will discuss the importance of predation in the regulation of sessile assemblages. These results may be valuable to elucidate recent questions on predator-prey interactions, and will constitute a pioneering work in southeastern Brazil. A better understanding of the mechanisms controlling community dynamics of the intertidal zone of rocky shores will help identifying potential key interactions, which is a necessary step towards an efficient management of these ecosystems. (AU)