Competencia interespecífica entre macroinvertebrados sésiles del sustrato rocoso intermareal de la playa El Pelado

Abstract

CONDITION FOR PUBLICATION OF PROJECT. This study evaluates the interactions between barnacles and mussels, two sessile species from the rocky intertidal zone, with the aim of analyzing space competition and its effects on coverage, growth, and survival. The hypothesis proposes that initial coverage proportions condition the outcome of competitive interactions, favoring scenarios of coexistence, exclusion, or proportional maintenance. The research seeks to provide empirical evidence on dynamic rarely tested under natural intertidal conditions in Ecuador. To achieve this, 25×25 cm quadrats were established with different coverage combinations between both species at El Pelado beach, Ecuador. Three replicates per treatment were installed across the upper and lower intertidal zones, and image-based coverage analyses were performed using ImageJ software, along with statistical tests carried out in InfoStat. Results showed that coverage remained stable in most treatments; ANOVA detected significant effects of treatment and its interaction with zone. No statistically significant changes in growth were observed. It is concluded that interspecific competition did not produce evident displacement between species in the short term, but did allow identification of scenarios where initial proportions were maintained or stable coexistence occurred under natural conditions. Keywords: sessile organisms, coverage, experimental design, ecological interactions, intertidal zone