Influência da complexidade do habitat na estrutura das assembleias e na dieta dos peixes em poças de maré em um recife de arenito, Paraíba

Abstract

Coastal reefs during low tides usually remain exposed, forming several tidepools, which can remain totally or partially isolated from the adjacent sea until the next high tide, they act in primary production, serve as a substrate for organisms and protect the coast. The structural complexity found favors the diversity of organisms in these environments, since it provides greater availability of shelter and food. This study aimed to evaluate the influence of the structural complexity of tidepools on the structure and diet of the ichthyofauna in a coastal sandstone reef. For this, fish samplings were made in the pools using eugenol to anesthetize the specimens and the aid of an aquarium net, in addition, structural and environmental parameters were measured: surface area, depth, volume, algal cover, number of refuges, roughness substrate, temperature and salinity. The structural characteristics divided the pools into two groups, pools with greater complexity (Alc) and pools with less complexity (N Alc). 5609 fish were caught in this study, distributed in 15 species, the most numerous, Scartella cristata, Bathygobius geminatus and Entomacrodus vomerinus. The more complex pools managed to attract greater density, biomass and wealth. The fish used mainly macroalgae and microcrustaceans as food resources, forming a total of three guilds (Herbivores, Omnivores and Zoobentivores). The structural complexity, mainly favored by the algal cover, positively influenced the ichthyofauna of the sandstone reef causing changes even in the diet of these organisms and thus in the ecological interactions. Tidal pools are nursery areas for fish species that benefit from the protection and availability of food in these habitats, increasing the chances of individuals reaching adulthood.