Fish from streams at the Juréia-Itatins Ecological Station: structure and conservation Cristina Gonçalves, María Angélica Pérez-Mayorga

Abstract

The Atlantic Forest is one of the most threatened ecosystems in the world and is home to an exceptional number of endemic species that are suffering from habitat reduction. In this work, we evaluate the structure of the ichthyofauna that occurs in the streams of the Juréia-Itatins Ecological Station (EEJI) in terms of species composition, abundance and biomass, discuss the threats to the ichthyofauna and suggest some conservation measures. The fish were sampled in 73 locations with different fishing gear (electric fishing, gill nets, pit traps and sieve) according to the possibilities of use in each environment (e.g. rapids and wells). 39 species were recorded, belonging to six orders and 17 families, totaling 7,719 individuals and approximately 32.2 kg. The orders Characiformes and Siluriformes were predominant in terms of richness, abundance and biomass. Most of the species (74.4%) occurred in exclusive freshwater environments and the rest of the species are tolerant to salinity and therefore were recorded in environments close to the influence of the tides. Many fish species endemic to the Atlantic Forest (61.5%) occurred in EEJI streams. Six species, Characidium schubarti (Crenuchidae), Scleromystax macropterus, S. prionotos (Callichthyidae), Pseudocorynopoma heterandria (Characidae), Hoplias lacerdae (Erythrinidae) and Brachyhypopomus jureiae (Hypopomidae), are on the state's official list of endangered species from Sao Paulo. The fish fauna sampled during this study complements previous inventories carried out in EEJI streams and represents a significant portion of the fish in the Atlantic Forest biome. The restricted distribution of most species increases their vulnerability to disturbances caused by human activities. In this way, UCs play a fundamental role in preserving aquatic fauna habitats. Considering the advanced degree of deforestation in the Atlantic Forest and the importance of UCs for the conservation of threatened and endemic species of this biome, the creation of new integral protection units such as EEJI is highly recommended.