Kyushu Bitterling (Rhodeus atremius)

Family: Cyprinidae

Kyushu Bitterling — a Cyprinidae from Korean Peninsula, mostly peaceful; keep with calm tankmates. Reaches 4.5–6.6 cm; loose shoals; groups of 6+ settle quickly. 10–25 °C.

Care parameters

Water temperature
10–25 °C
pH
6.8–7.8
GH hardness
5–15 dGH
Adult length
4.5–6.6 cm
Minimum tank
52 L
Water layer
Bottom-dwelling
Difficulty
Moderate
Temperament
Mostly peaceful; keep with calm tankmates
Origin
Korean Peninsula

Species overview

A Cyprinidae species native to Korean Peninsula: Rhodeus atremius lives bottom-dwelling over gravel. Mostly peaceful; keep with calm tankmates. Adults reach 4.5–6.6 cm. It is one of the aquarium-kept Rhodeus species we profile, alongside Rhodeus fangi, Rhodeus lighti, Rhodeus ocellatus.

Native biotope

Habitat
Clear streams and rivers over gravel
Flow
Moderate, well-oxygenated current
Dissolved O₂
Appreciates well-oxygenated water

Aquascape & hardware

Substrate
Fine gravel and sand
Hardscape
Water-worn stones and driftwood
Plants
Hardy rooted plants along the margins

Temperament, diet & tankmates

Schooling
Loose shoals; groups of 6+ settle quickly
Diet
Small omnivore; flakes, granules and vegetable matter
Recommended tankmates
  • Other small peaceful cyprinids — Similar size, similar water
Avoid keeping with
  • Fin-nippers — Their flowing fins invite damage

Breeding & notes

Sexual dimorphism
Males often slimmer and more colourful
Breeding method
Deposits eggs in freshwater mussels; no aftercare

Frequently asked questions

Is Kyushu Bitterling easy to keep?

Difficulty: moderate. Mostly peaceful; keep with calm tankmates. Loose shoals; groups of 6+ settle quickly.

What temperature and water chemistry does Kyushu Bitterling need?

Set the heater to 10–25 °C and avoid swings. pH 6.8–7.8, GH 5–15 dGH suit it.

How big does Kyushu Bitterling get, and what tank size?

Adults reach 4.5–6.6 cm; it is bottom-dwelling. Plan for at least 52 litres.

What does Kyushu Bitterling eat?

Small omnivore; flakes, granules and vegetable matter. Vary the menu — quality flakes or pellets plus frozen or live foods.

Can Kyushu Bitterling live with other fish?

Mostly peaceful; keep with calm tankmates; loose shoals; groups of 6+ settle quickly. Good company: Other small peaceful cyprinids — Similar size, similar water. Keep away from Fin-nippers — Their flowing fins invite damage.

Where does Kyushu Bitterling come from?

Its home waters are Korean Peninsula — clear streams and rivers over gravel, with moderate, well-oxygenated current.

Does Kyushu Bitterling jump?

Not a noted jumper — a standard cover still keeps dust and spray in.

How does Kyushu Bitterling breed?

In the aquarium: deposits eggs in freshwater mussels; no aftercare. Males often slimmer and more colourful.