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Javanese Medaka Rice Fish swimming in a clear tank, showcasing small freshwater fish with colorful fins and distinctive markings.
JA Javanese Medaka Rice Fish swimming in an aquarium, showcasing its vibrant colors and small size in a natural aquatic environment.
Javanese Medaka Rice Fish swimming in a clear aquatic environment, showcasing vibrant colors and small size.
Javanese Medaka Rice Fish by JA, small colorful freshwater fish swimming in an aquarium, highlighting vibrant orange and white scales.
Javanese Medaka rice fish swimming in a clear aquarium, showcasing its small, colorful body and distinctive fins.
Japanese Javanese Medaka rice fish swimming in a clear aquarium, showcasing vibrant colors and small size.
Javanese Medaka Rice Fish by JA, small colorful freshwater fish with vibrant orange and white markings in an aquatic environment.
JA Javanese Medaka Rice Fish swimming in a clear aquarium, showcasing vibrant colors and small size typical of this freshwater fish.
Javanese Medaka Rice Fish swimming in a clear tank, showcasing small freshwater fish with colorful fins and distinctive markings.
JA Javanese Medaka Rice Fish swimming in an aquarium, showcasing its vibrant colors and small size in a natural aquatic environment.
Javanese Medaka Rice Fish swimming in a clear aquatic environment, showcasing vibrant colors and small size.
Javanese Medaka Rice Fish by JA, small colorful freshwater fish swimming in an aquarium, highlighting vibrant orange and white scales.
Javanese Medaka rice fish swimming in a clear aquarium, showcasing its small, colorful body and distinctive fins.
Japanese Javanese Medaka rice fish swimming in a clear aquarium, showcasing vibrant colors and small size.
Javanese Medaka Rice Fish by JA, small colorful freshwater fish with vibrant orange and white markings in an aquatic environment.
JA Javanese Medaka Rice Fish swimming in a clear aquarium, showcasing vibrant colors and small size typical of this freshwater fish.

Javanese Medaka Rice Fish

Sold out
$ 31.99 - $ 60.99
$ 31.99
$ 31.99 - $ 60.99
$ 31.99
Size: 6 Pack

Species Profile

Javanese Rice Fish (Oryzias javanicus) are native to coastal mangrove zones, brackish estuaries, and freshwater streams across Southeast Asia. Unlike domestic medakas bred for bright color morphs, these fish feature a semi-translucent, pearlescent body with subtle green, yellow, or smoky accents that catch overhead light. In a planted aquarium, they stay in the mid to upper water column, providing steady movement against dark substrate and dense stems without picking at live plants or uprooting delicate foreground carpeting. Their natural adaptability to both freshwater and brackish environments makes them tough and versatile, though their surface-oriented feeding habits mean you will want a tight-fitting lid to prevent jumping.

**Note: All livestock orders will come carefully packaged with solid wall Styrofoam insulation and shipped via 1-day shipping only. No extra insulation needs to be added to your cart for your livestock.

Key Features & Notes

  • Translucent pearlescent body with subtle iridescent accents provides clean contrast against dark hardscape and dense foliage.
  • Active top-level nano schooler that stays plant-safe and leaves carpet plants rooted.
  • Euryhaline species capable of thriving in soft freshwater, hard alkaline setups, or brackish systems.

Acclimation & Care Instructions

  • Float the sealed transport bag for 15 to 20 minutes to equalize water temperatures before opening.
  • Drip acclimate over 30 to 45 minutes using airline tubing to ease them gently into your tank parameters.
  • Maintain tropical temperatures between 72°F and 82°F; unlike temperate Japanese medakas, Javanese rice fish need consistent warmth.
  • Fit the aquarium with a secure lid or generous floating plant cover; active rice fish can jump when startled.
  • Provide gentle to moderate surface circulation; strong filter turbulence can tire out small surface swimmers.
  • Feed crushed flakes, micro pellets, or baby brine shrimp once or twice daily to suit their small, upturned mouths.
  • Translucency and accent intensity vary naturally between individuals and deepen under full-spectrum lighting.

Quick Facts

Listed information should be treated as general guidelines only. Team Buce Plant encourages you to do thorough research to ensure healthy livestock!

Attribute Specification
Scientific Name Oryzias javanicus
Common Name(s) Javanese Rice Fish, Java Medaka
Family Adrianichthyidae
Care Difficulty Easy
Diet Omnivore (Crushed flakes, micro pellets, baby brine shrimp, daphnia)
Plant Safe Yes (Safe with aquatic plants, carpets, and floaters)
Temperament Peaceful mid-to-top column schooler
Adult Size 1.0"–1.5" (2.5–3.8 cm)
Minimum Tank Size 10+ Gallons (Best in groups of 6+)
Water Parameters pH 7.0–8.2 | GH 6–15 | KH 4–10 | 72°F–82°F (22°C–28°C) | Brackish tolerant
Freshwater Breeding Yes (Egg hangers on fine mosses, floating roots, and yarn mops)
Origin Southeast Asia (Tank-bred)

Frequently Asked Questions

1. Do Javanese Rice Fish need an aquarium heater?

Yes. While Japanese rice fish (Oryzias latipes) tolerate cold water, Javanese rice fish are tropical natives from Southeast Asia. They need a steady water temperature between 72°F and 82°F to maintain proper immune function, feed normally, and stay active.

2. Can Javanese Rice Fish live in fresh water, or do they require salt?

They thrive in standard freshwater planted tanks. They are a euryhaline species, meaning they can tolerate a wide salinity range from pure freshwater to mild brackish environments, but adding salt is not required for general health or breeding.

3. How do Javanese Rice Fish breed in an aquarium?

Females carry clusters of fertilized eggs near the anal vent each morning before depositing them into fine-leafed stem plants, mosses, or spawning mops. For a complete walkthrough on water conditions, feeding, and fry collection, check out our comprehensive Japanese Rice Fish Care Guide.

4. Are Javanese Rice Fish safe to keep with dwarf shrimp?

Adult Neocaridina and Caridina shrimp are safe alongside them. Because these fish stay near the surface and have very small mouths, they do not bother bottom-grazing adult shrimp. Tiny shrimplets swimming out in open water can be picked off opportunistically, so maintaining dense moss clumps and low-growing ground cover helps maximize shrimplet survival.