EXPERIMENTAL ANALYSIS ON BEHAVIORAL RESPONSES OF Tridentiger obscurus TO HYPOXIA USING DISSOLVED-OXYGEN-AND-SALINITY-GRADIENT AQUARIUM

Abstract

 Demersal fish was forced to live near sea surface in a eutrophic sea area because hypoxic water was formed near sea bottom. There was no habitat for demersal fish near sea surface in urban canal because all coastal line was formed by vertical seawall. Environment-friendliness seawall is an effective solution because the seawall can provide a habitat for demersal fishes. This study focuses on design requirement of environment-friendliness seawall, especially inhabitable water quality level of DO for demersal fish, we conducted experiments using small aquarium which can control water quality difference in vertical direction. As a result, we found threshold level of DO for Dusky tripletooth gody(Tridentiger obscurus) was lower than other kind of fishes and Dusky tripletooth gody can live without any abnormal behavior in a condition of DO> 1.0mg/L.