Competition between mussels at the rocky intertidal zone of La Lobería, Río Negro, Argentina

ARRIBAS, L. P.; BAGUR, M.; SORIA, S. A.; JORGE LUIS CEFERINO GUTIERREZ; PALOMO, M.G.

Revista del Museo Argentino de Ciencias Naturales

Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"

Año: 2016

Competitive interactions between individuals from a single or different speciescan regulate population densities and individual growth. Two mussel species, Brachidontesrodriguezii and B. purpuratus, coexist in the rocky intertidal zone ofLa Lobería, Río Negro Province, Argentina. The aim of this study was to analysethe effect of intra- and interspecific competition in the growth and mortalityof both bivalve species. An experiment was conducted to evaluate the intra- andinterspecific competition using asbestos cement plates of 10 x 10 cm varyingmussel densities. The results showed a trend toward decreasing size of B.rodriguezii with increasing density of conspecifics and when it coexistswith B. purpuratus, but only the width of B. purpuratus showedsignificant increase in presence of B. rodriguezii. Mortality of B.rodriguezii and B. purpuratus did not significantly differ betweentreatments. Limited supply of B. purpuratus larvae or local tidalconditions that differentially affect each species could be leading to weak competitionbetween both mussels species, thus allowing their coexistence.