Bioprospecção de poliquetas para insumos em maricultura: biodiversidade e composição bioquímica

Abstract

Polychaetes are among the three main groups of benthic macrofauna. They have a wide variety of shapes and appendages, which gives them the skills to inhabit different types of substrates and obtain differentiated food resources. Historically, it is known that they are used as bait in communities that practice artisanal fishing and there is an expansion of this activity in the economy with the exploitation of this resource in the natural environment, removing tons of polychaetes and moving thousands of dollars around the world. Furthermore, polychaetes have been studied in other areas, such as mariculture and marine biotechnology, having their use in the feeding of commercially valuable species, mainly in the cultivation of shrimp and in the bioremediation of organic matter in the effluents of mariculture nurseries. However, the cultivation of polychaetes to meet the demand of these sectors is still difficult to establish and maintain, making studies on the way of life, distribution, reproduction and biochemical composition of these species necessary and also an analysis in groups of individuals, such as functional feeding groups. This study aimed to expand the knowledge of the polychaete biodiversity in Enseada dos Anjos, in Arraial do Cabo / RJ, as well as to understand the distribution of its density and the trophic groups relating them to environmental variables, and the biochemical composition of these organisms to form trophic groups. 103 polychaetes morphotypes were identified, belonging to 51 species, 71 genera and 31 families in a total of 2,300 specimens collected. 31 new records were observed for the internal Continental Platform of Arraial do Cabo and six new records for the state of Rio de Janeiro. Enseada dos Anjos is structured according to the granulometry of the sediment, ranging from coarse to fine grains in the south-north direction. The intensity and direction of the wind seem to influence the marine currents that enter the inner portion of the inlet, moving the most superficial layers of the unconsolidated substrate, determining the presence of species that inhabit this area, more related to the surface depositivorous trophic group. At the Cais station, protected from the direct action of the northeast winds by the breakwater of Forno Port, the variation of species between the four trophic groups is not perceived, as was observed at the Hotel and Tayo stations. The highest concentration of protein was found in the depositivore group. The minerals that stood out in greater quantity were calcium, phosphorus, iron and magnesium. Phosphorus was found in higher values in animals with a carnivorous habit and the other minerals in animals with a depositivorous habit. It can be concluded that environmental variations directly affect the survival of polychaetes. However, the presence of different trophic groups can favor their permanence in the environment. In a species cultivation, variations in the physicochemical conditions of the water or the speed of the water flow in the breeding pond can affect the organisms present there. The creation of different species of the same trophic group, for example, depositivores, can favor not only the continuity of cultivation, but also the improvement of the offer of species as a product or service. Keywords: Trophic groups, Food, Fishing.