Rhodeus sciosemus is a subtropical 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 Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

. It was originally described as Acanthorhodeus sciosemus by Jordan & Thompson in 1914.

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