Comunidade de moluscos associados a macroalgas em ambientes recifais: Uma abordagem funcional

Abstract

Habitat complexity is a structural factor of the community of molluscs associated to algal environments, since each species of macroalga offers a type of structurally different habitat. In this study, we evaluated whether the structural complexity of three macroalgae spec ies influences the diversity and functional richness of the associated malacofauna and which algal morphological features influence the functional traits of the mollusc community. Macroalgae with greater structural complexity, such as Bryothamnion triquetrum and Sargassum polyceratium, harbored greater abundance of individuals and greater diversity and functional richness in relation to the macroalga Padina gymnospora, of minor structural complexity. Morphological attributes of macroalgae were related to the composition of functional traits of the mollusc community. The higher algal height favored the existence of species with high fecundity, spawning released in the water and detritivore feeding habit. The algal width was related to species with average fecundity and larval planktotrophic development. The wet weight and the complexity of the habitat were related to the presence of species of small size and average life time. The width of the thallus at level 1 and the degree of branching favored the presence of species with direct larval development and carnivorous food habit. The width of the thallus at level 2 and 3 were related to species of short and medium length of life. These results suggest that macroalgae offer the marine mollusks of fital different possibilities of substrates, allowing functionally diverse individuals to inhabit their banks. In addition, they make the reef environments more heterogeneous, increasing the opportunities of colonization and microhabitats for different organisms that live and depend on the algal system.