Species profile
Japanese Ricefish
Oryzias latipes
Peaceful
Easy care
50 L minimum aquarium
3–4 cm adult size
Top mid
Minimum group: 8
About this species
General notes for hobby use.
Temperate medaka; it should not be locked into a narrow 18–23°C tropical-style range.
Water parameters
Suggested general range for long-term care.
Temperature
10–28 °C
pH
6.5–8.5
GH
5–20 dGH
KH
Not yet documented
Flow preference
Low–moderate
Data confidence
Verified
Behaviour
General behaviour traits used by TanksConnected compatibility checks.
Minimum group size
Minimum group: 8
Tank zone
Top mid
Territory level
Low
Predation risk
None
Bioload factor
1.5
Peaceful social fish; keep a group of eight or more and provide a secure lid.
Compatibility flags
Quick cautions for common tank-planning issues.
Fin nipper
No
Plant safe
Yes
Shrimp safe
Yes
Snail safe
Yes
Cave breeder
No
Digs substrate
No
Jump risk
Yes
Natural history & care
Research-backed context for long-term aquarium care.
Lifespan
Not yet documented
Diet type
Omnivore
Minimum aquarium volume
50 L
Minimum footprint
60 × 30 cm
Accepted scientific name
Oryzias latipes
Native range
East Asia; native populations occur in Japan and nearby parts of East Asia, with introductions elsewhere.
Natural habitat
Shallow, slow or still waters including rice paddies, ponds and streams. A planted unheated aquarium or seasonal outdoor setup is suitable where temperatures remain safe.
Diet & feeding
Fine dry foods, small aquatic invertebrates and live/frozen foods.
Breeding & sexing
Research-backed guidance for identifying sexes and reproductive behaviour.
Sexing
Males generally have longer dorsal/anal fin rays; females are fuller-bodied and may be seen carrying egg clusters.
Breeding
Frequent non-annual spawner. Females carry a cluster of fertilised eggs briefly before attaching them to plants or spawning media.