Testing the accuracy of biological attributes in predicting extinction risk

•We tested the accuracy of biological attributes to predict reef fish species’ vulnerability to extinction.•Megafauna, carnivorous, mobile invertivorous, habitat specialists, highly mobile species and Elasmobranchii have greater extinction risks.•Reef sites along southestern Brazil have greater proportions and richness of threatened species.•Biological attributes may be a tool to predict the vulnerability of reef fishes.