Community structure of an assemblage of tidepool fishes on a tropical eastern Pacific rocky shore, Colombia

Abstract

The composition, abundance, species richness and diversity of a rocky intertidal fish assemblage in the central zone of the Pacific coast of Colombia were determined. From July to December 2002, 10 tidepools with volumes ranging from 0·087 to 1·350 m3 were surveyed. A total of 893 fishes belonging to 14 species and 12 families were found. The most abundant species were Bathygobius ramosus and Abudefduf concolor, representing 71% of all fishes collected. Bathy gobius ramosus, Malacoctenus zonifer and Gobiesox adustus were residents, Abudefduf concolor, Abudefduf troschelii, Microsphatodon bairdii, Chaenomugil proboscideus, Halichoeres aestuaricola and Echidna nocturna were transients, and Apogon dovii, Sargocentron suborbitalis, Cerdale sp, Rypticus nigripinnis and Ctenochaetus marginatus were considered as accidental visitors. The temporal and spatial variation of assemblage structure was tested. The fish assemblage structure did not differ between months and there was not a clear relationship between tidepool surface area and depth, and community variables. Diversity and species richness were negatively correlated with tidepool height. It is suggested that the tidepool assemblage was stable and resilient in time on short (annual) scales. The constancy in time and space could have been a consequence of eurytopic features of the organisms and the lack of drastic seasonal changes in the tropics.