Rhodeus pseudosericeus is a temperate freshwater fish belonging to the Acheilognathinae subfamily of the family Cyprinidae. It originated in the Namhan River system in the Gyeonggi-do and Gangwon-do provinces of Korea. It was originally described as Acanthorhodeus atremius by Jordan & Thompson in 1914. The fish reaches a length up to 6.1 cm (2.4 in). When spawning, the females deposit their eggs inside bivalves, where they hatch and the young remain until they can swim.