Rhodeus uyekii is a temperate

Temperate

In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally relatively moderate, rather than extreme hot or cold...

 freshwater

Freshwater

Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...

 fish

Fish

Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

 belonging to the Acheilognathinae

Acheilognathinae

Acheilognathinae, the bitterling-like cyprinids, are a subfamily of cyprinids.Genera contained herein are:* Acanthorhodeus – spiny bitterlings* Acheilognathus* Rhodeus – bitterlings* Tanakia...

 sub-family of the Cyprinidae family. It originates in inland rivers in South Korea

South Korea

The Republic of Korea , , is a sovereign state in East Asia, located on the southern portion of the Korean Peninsula. It is neighbored by the People's Republic of China to the west, Japan to the east, North Korea to the north, and the East China Sea and Republic of China to the south...

. It was originally described as Pseudoperilampus uyekii by T. Mori in 1935. The fish reaches a size of up to 6.0 centimetres (2.4 in).

When spawning, the females deposit their eggs inside bivalves, where they hatch and the young remain until they can swim.