Life history differences enhance invasiveness and syntopic distribution: a comparative study with three congeneric marine species along Southwest Atlantic coast

Introductions of close related species provides an opportunity to study differences in life history traits and their ability to cooccur in syntopy. We examine a case in which three species of Megabalanus barnacles coexist syntopically along the tropical southwestern Atlantic. A comparative life history study, focusing on parameters such as size, distribution, abundance, growth, and reproduction is presented. Through such an analysis, we could better understand the successful establishment of the non-indigenous M. coccopoma in the southwestern Atlantic, discern why the cryptogenic M. tintinnabulum flourishes across approximately 5000 km of Brazilian shores, and probe how the endemic M. vesiculosus occurs with these two species. Although we did not measure growth and reproduction period, the higher egg size and fecundity of M. vesiculosus might be allowing its extensive range of occurrence. The observed superior density of M. coccopoma in southern locations might be directly associated with its continuous reproduction period and fecundity. But the absence of M. coccopoma on northern shores can be attributed to the smaller egg size, not work wheel on oligotrophic warm water. The faster growth rate and large adult size of M. tintinnabulum appear to be beneficial in competitive intertidal environments of tropical shores. This study showed how close related species diverge in traits, and how such differences may act when in syntopy. The knowledge of how these factors relate to the establishment of nonindigenous species may furnish tools to understand future invasion scenarios.