2021 Volume 2021 Issue 31 Pages 62-67
Based on a review of previous reports and literature records, I examine changes in the freshwater fish fauna of Sado Island. With the addition of two primary and one peripheral freshwater species after the last faunal report in 2012, the number of species in the freshwater fish list of the island has been increased to 46. The fauna is predominantly characterized by a high richness of diadromous species, particularly amphidromous gobiids, and this has remained essentially unchanged over the last 60 years. However, the proportion of primary freshwater species has been increased from one fourth to one third due to anthropogenic introductions, raising concerns about the impact of the introduced species on the aquatic ecosystem. I give a brief discussion on preventive measures to be taken against species introductions, as well as environmental DNA-based monitoring of fish assemblages to be implemented for early detection of invasions.
