Peixes de poças de maré do Nordeste do Brasil: estrutura da comunidade, sazonalidade e conectividade genética

Abstract

The composition, structure and seasonal patterns of distribution of tidepools fishes in northeast Brazil were determined. One hundred tidepools were surveyed from december 2010 to august 2012. A total of 3586 specimens belonging to 52 species and 24 families were captured, with the dominance of resident species, cryptic, and mobile invertebrate predators species. The most abundant species were Bathygobius soporator, B. geminatus and Stegastes fuscus, representing 14.95%, 13.11% and 10.54% of all fishes captured, respectively. Significant differences related to the composition of ichthyofauna between the sampling sites were not observed. In the dry season, 2031 specimens of 49 species and 23 families were sampled and, in the wet season, 1555 specimens of 56 species and 22 families were sampled in the tidepools. Of these, B. geminatus and B. soporator were the most abundant and frequent species in the both seasons. Significant differences in the total abundance of species between the dry and wet seasons were detected. Indirect evidence suggests that seasonal variation in abundance may be result of the increment of recruits individuals from intertidal and subtidal zones surrounding. Environmental factors such as depth, temperature, salinity, macroalgae, zoanthids and marine terrigenous clastics aggregates (sand and gravel) affected the community structure of fishes, resulting in spatial variability in the tidepools analyzed. Thus, the seasonal relations and spatial patters observed may be explained according to their reproductive cycles and habitat requirements, respectively.