Temporal variation of fish community richness in coastal lagoons of the Restinga de Jurubatiba National Park, Rio de Janeiro, Brazil

Abstract

. Fish species were sampled in August/2001 (dry season) and February/2002 (rainy season) from seven coastal lagoons of the Restinga de Jurubatiba National Park, located in a “restinga” (sandy coastal plain vegetation) of the State of Rio de Janeiro. Water samples were collected from each lagoon in both seasons for analysis of pH, total phosphorous, water colour and salinity. Data about lagoon area, connected to sea or rivers, and presence of aquatic macrophytes were obtained from literature and by fieldwork trips. We registered 21 fish species belonging to 13 families and six orders: 7 Characiforms species (33%), 5 Perciforms (24%), 4 Cyprinodontiforms (19%) and 5 species of Clupeiforms, Siluriforms and Atheriniforms orders (24%). Cabiúnas and Carapebus lagoons presented highest richness values (16 and 13 species, respectively), followed by Paulista (10 species), Comprida (5), Preta and Piripiri (3), and Garças (none). The similarity index values showed seasonal influence in species composition. The groups of lagoons generated by PCA were the same for both sampling periods and their spatial projection influenced by changes in salinity, pH and total phosphorus. Species richness of fishes were positively correlated to the richness of aquatic macrophytes and connection with other ecosystems. The main factors involved in the predominant freshwater fish fauna of the lagoons are the scarce and eventual link to the sea and the seasonal regime of rains.