First record of the invasive fish species Odontobutis potamophila (Günther) in Tokyo, Japan, collected from the Edo River in the Tone River system

Abstract

Odontobutis potamophila (Günther) is a freshwater fish native to northern Vietnam and eastern China. In Japan, this species was first identified in 2010 in Sugao Swamp in the Tone River system in Ibaraki Prefecture. The distribution of the species is expanding in the Tone River. In this study, an individual of the species was collected in the Edo River, a tributary of the Tone River system. The collected fish would have entered the river via two routes: one by streamflow via the Tone Canal from a known habitat and the other via direct release by someone. Its feeding habit may have a negative impact on native ecosystems. The continuous monitoring and management of this species is necessary during the early stages of its invasion.