Black Rice Fish - Oryzias latipes

Black Rice Fish – Oryzias latipes

The Black Rice Fish is an attractive freshwater fish admired for its deep black colouration, slender body shape and lively swimming behaviour. Also known as the Black Medaka or Black Japanese Ricefish, this selectively bred variety of Oryzias latipes is an excellent choice for planted aquariums, temperate freshwater setups and peaceful community displays. Hardy, active and relatively easy to care for, Black Rice Fish are particularly appealing when kept in groups against green aquatic plants and lighter substrates.

Common Name: Black Rice Fish, Black Medaka, Black Japanese Ricefish, Black Ricefish

Scientific Name (Latin): Oryzias latipes

Strain / Form: Black captive-bred Medaka colour variety

Maximum Size: Approximately 3–4 cm

Water Type: Freshwater

Origin / Natural Habitat: Wild Oryzias latipes originate from East Asia, particularly Japan and Korea, where they inhabit rice paddies, shallow ponds, marshes, drainage channels and slow-moving freshwater streams.

These habitats commonly contain aquatic vegetation, shallow water and areas with gentle water movement.

The Black Rice Fish is a selectively bred aquarium variety rather than a naturally occurring wild colour form.

In the aquarium, it thrives in mature planted environments with open swimming areas, floating vegetation and stable water conditions.

Water Parameters: Temperature: 16–24°C pH Range: 6.5–8.5 Hardness: Soft to hard (approximately 5–25 dGH) Ammonia/Nitrite: 0 ppm Nitrate: Kept low and stable Flow: Gentle to moderate preferred

Temperament: Peaceful / Active

Black Rice Fish are peaceful, sociable fish that are best kept in groups.

They spend much of their time swimming in the upper and middle levels of the aquarium and are generally compatible with other peaceful species that enjoy similar water conditions.

Males may occasionally display or chase one another, particularly during breeding, but serious aggression is uncommon.

Diet: Omnivore / Small Community Diet

Black Rice Fish readily accept a varied diet of appropriately sized aquarium foods.

Offer high-quality tropical flakes, micro pellets and small floating granules as their staple diet.

Supplement with frozen or live foods such as daphnia, cyclops, baby brineshrimp, mosquito larvae and finely chopped bloodworm.

A varied diet helps support healthy growth, strong colouration and breeding condition.

Minimum Tank Size: Approximately 45–60 litres for a small group

A longer aquarium with plenty of surface swimming space is preferred over a tall aquarium.

Larger aquariums are recommended for bigger groups, breeding colonies or mixed community setups.

Behaviour & Activity: The Black Rice Fish is an active, confident species that spends much of its time swimming near the surface and exploring planted areas.

When kept in groups, individuals display natural social behaviour, including gentle chasing and courtship displays.

This species is an egg-layer. Females may temporarily carry clusters of fertilised eggs attached near the underside of the body before depositing them among plants or spawning mops.

In well-planted aquariums, some fry may survive among dense vegetation, although adults may eat eggs or newly hatched young.

Their dark colouration makes them particularly attractive against bright green plants and pale aquarium substrates.

Community Suitability: Peaceful Community Fish

Black Rice Fish are excellent additions to peaceful temperate and cooler tropical community aquariums.

Suitable tankmates include White Cloud Mountain Minnows, other Medaka Ricefish, compatible small danios, peaceful temperate rasboras, suitable small corydoras and freshwater shrimp with caution.

Choose tankmates that tolerate similar temperatures and water conditions.

Avoid aggressive fish, fin-nippers, large predators and species that require consistently high tropical temperatures.

Special Requirements or Care Notes: Keep Black Rice Fish in a group of at least six, with eight or more preferred where space allows.

They are adaptable fish but prefer cooler freshwater conditions rather than permanently heated tropical aquariums.

A temperature of approximately 18–22°C is particularly suitable for routine aquarium maintenance.

They can be kept in unheated indoor aquariums where room temperatures remain within a suitable range.

Outdoor keeping may be possible in appropriately managed seasonal setups, but extreme temperatures, freezing conditions and rapid temperature changes must be avoided.

Provide floating plants, fine-leaved vegetation and sheltered areas while leaving sufficient open swimming space.

A secure lid or cover is recommended, as Rice Fish can jump when startled.

If breeding is desired, provide spawning mops or fine plants where females can deposit their eggs.

Black Rice Fish may breed with other colour varieties of Oryzias latipes, so keep strains separate if maintaining a particular colour line is important.

Regular water changes, stable conditions and a varied diet will help maintain their colouration and long-term health.

Suitable for: Beginner

Availability: Common to occasional, depending on supplier, breeding line and seasonal availability.

All images are a visual representation of the fish you will receive, made to be as accurate as possible. Please note that Mother Nature is a wonderful thing, and variation in patterns and colours will occur — that is part of the unique beauty of these animals.