Curved-back Rice Fish (Oryzias curvinotus)

Family: Adrianichthyidae

A peaceful omnivore adrianichthyidae from South China (Guangdong, Guangxi and Hainan) — beginner-friendly.

Care parameters

Water temperature: 18–26 °C
pH: 6.5–7.5
GH hardness: 5–15 dGH
Adult length: 2.8–4 cm
Minimum tank: 40 L
Water layer: Upper; surface-oriented; keep 6+
Difficulty: Easy
Temperament: Peaceful
Origin: 中国华南（广东、广西、海南）

Species overview

Oryzias curvinotus is a Adrianichthyidae. In the aquarium it stays peaceful. Plan on 2.8–4 cm of adult fish at 18–26 °C. Related profiles: Oryzias javanicus, Oryzias latipes, Oryzias sinensis.

Native biotope

Habitat: Clear streams, rivers and still waters
Flow: Still to very gentle water
Dissolved O₂: Average oxygen needs

Aquascape & hardware

Substrate: Dark fine gravel or sand
Hardscape: Driftwood, water-worn stones and shelters that mimic the native biotope
Plants: Dense floating plants for cover and security

Temperament, diet & tankmates

Schooling: Keep 6+; larger groups settle better
Diet: Omnivore; quality prepared foods with variety
Recommended tankmates: Amur False Gudgeon — Similar size and water needs
China-Bitterling — Similar size and water needs
Acanthorhodeus chankaensis — Similar size and water needs
Avoid keeping with: Large aggressive cichlids — Bullying and injury risk
Known fin nippers — Constant stress and fin damage

Breeding & notes

Sexual dimorphism: Males are typically slimmer and more intensely colored; females fuller-bodied
Breeding method: Egg-scatterer over fine plants; condition with rich foods and simulate seasonal changes

Frequently asked questions

Is Curved-back Rice Fish easy to keep?

Rated easy — peaceful.

What temperature and water chemistry does Curved-back Rice Fish need?

Hold 18–26 °C and keep it stable — community-standard range; verify locally. Standard heater to hold the mid-range steadily.

How big does Curved-back Rice Fish get, and what tank size?

Expect 2.8–4 cm as an adult, living upper; surface-oriented; keep 6+. A 40 L tank or larger gives it room.

What does Curved-back Rice Fish eat?

Omnivore; quality prepared foods with variety. Vary the menu — quality flakes or pellets plus frozen or live foods.

Can Curved-back Rice Fish live with other fish?

Peaceful; keep 6+; larger groups settle better. Good company: Amur False Gudgeon — Similar size and water needs, China-Bitterling — Similar size and water needs, Acanthorhodeus chankaensis — Similar size and water needs. Keep away from Large aggressive cichlids — Bullying and injury risk, Known fin nippers — Constant stress and fin damage.

Where does Curved-back Rice Fish come from?

Comes from 中国华南（广东、广西、海南）: clear streams, rivers and still waters. Expect still to very gentle water and average oxygen needs.

Does Curved-back Rice Fish jump?

Low escape risk, but a lid is cheap insurance.

How does Curved-back Rice Fish breed?

Egg-scatterer over fine plants; condition with rich foods and simulate seasonal changes. Males are typically slimmer and more intensely colored; females fuller-bodied.