Acanthogobius flavimanus is a species of fish in the goby family known by the common name yellowfin goby. Other common names include mahaze, Japanese river goby, Oriental goby, and spotted goby. It is native to Asia, where its range includes China, Japan, Korea, parts of Russia, Vietnam, and Malaysia. It has spread beyond its native range to become an introduced, and often invasive, species. It has been recorded in Australia, Mexico, and Florida and California in the United States.