Padrão de recrutamento de peixes de poças de maré do Atlântico sudoeste

Abstract

In population ecology, the recruitment process is essential for the maintenance of populations and meta-populations and, therefore, understanding this aspect is fundamental for understanding the dynamics of ecosystems. In this sense, the recruitment process of a species can be defined as the settlement and survival of juveniles in the environment. In general, the intertidal period can be characterized by the high variability of abiotic parameters as result of air exposure caused by low tide. The recruitment patterns of benthic organisms, mainly sessile ones, are relatively known, but for fish, this process remains little studied. Between 2005 and 2007, quarterly collections of ichthyofauna were carried out in six tide pools on a flat reef in the southwest Atlantic intertidal zone, on what it was possible to detect the recruitment patterns of 17 fish species. Through simple linear regression analysis, the recruitment period for each analyzed species was determined, and calculations of the parameters of the von Bertalanffy equation were performed to estimate the maximum length that the species reaches while inhabiting the tide pools. Thus, it was possible to observe that 9 species presented recruitment events during the dry season (r = 0.72 – 0.92; R2 = 0.52 – 0.84) and 8 during the rainy season (r = 0.70 - 0.90; R2 = 0.45 - 0.81). We identify that congeneric species recruited at the same time of the year, while species that share the same ecological needs (e.g., species belonging to the same family, such as the Gobiidae family and Labrisomidae) do not recruit at the same time. With this, it can be inferred that the Castelhanos tide pools offer ideal conditions that allow the recruitment of species throughout the year, acting as a nursery environment and refuge for a variety of fish species. Finally, aspects related to the life history of these species are essentially important in determining recruitment events that culminate directly in population dynamics and community structure. In this way, the temporal and nursery use for species that are ecologically important both for the intertidal and reef environments in other regions is clear.