Interações biológicas e suas consequências relacionadas à introdução de espécies exóticas de Ascidiacea e outros grupos em comunidades bioincrustantes

Abstract

Considered one of the main causes of the extinction of native species within an ecosystem, the bioinvasions dynamics, especially in tropical regions, are extremely important. Due to their high colonization capacity, organisms belonging to the subphylum Tunicate, class Ascidiacea, are among the main groups of organisms introduced into environments and with invasive potential. With the aim of evaluating the speed of action of pelagic predators on the community structure, in addition to analyzing the susceptibility of Ascidiacea species to predation according to their morphofunctional characteristics, structures formed by adapted exclusion cages, containing polyethylene plates in their interior, were kept immersed for 10 months, allowing us to observe and compare how pelagic predation acted on these established benthic communities. A total of 24 taxa were recorded, 16 of which were identified in species. Ten species were indicated as exotic, among them, the solitary ascidian Ascidia sydneiensis and the colonial Didemnum perlucidum, species with the highest percentage of contribution (22%), followed by the cryptogenic solitary ascidian Phallusia nigra (16%). The great importance that maritime traffic has to the IGB, over the years, has generated many opportunities for marine bioinvasions, and there is evidence for the idea that biotic resistance mediated by predation plays an important role in the control of exotic species, where the maintaining a natural and diverse community of predators can be very effective.