Resumen de Competition between mussels at the rocky intertidal zone of La Lobería, Río Negro, Argentina
Lorena Pilar Arribas, María Bagur, Sabrina A. Soria, Jorge L. Gutiérrez, M. Gabriela Palomo
Competitive interactions between individuals from a single or different species can regulate population densities and individual growth. Two mussel species, Brachidontes rodriguezii and Perumytilus purpuratus, coexist in the rocky intertidal zone of La Lobería, Río Negro Province, Argentina. The aim of this study was to analyse the effect of intra- and interspecific competition in the growth and mortality of both bivalve species. An experiment was conducted to evaluate the intra- and interspecific competition using asbestos cement plates of 10 x 10 cm varying mussel densities. The results showed a trend toward decreasing size of B. rodriguezii with increasing density of conspecifics and when it coexists with P. purpuratus, but only the width of P. purpuratus showed significant increase in presence of B. rodriguezii. Mortality of B. rodriguezii and P. purpuratus did not significantly differ between treatments. Limited supply of P. purpuratus larvae or local tidal conditions that differentially affect each species could be leading to weak competition between both mussels species, thus allowing their coexistence.
