Komachi Medaka Rice Fish

Species Profile

Komachi Medaka Rice Fish (Oryzias latipes) are a prized Japanese domestic strain inspired by the classic Kohaku coloration of ornamental koi, featuring distinct patches of fiery orange set against a clean, milky porcelain-white base. In a planted aquarium, they cruise the upper third of the water column, adding bold two-tone contrast against dark substrate, driftwood, and lush green stem plants. They are peaceful nano schoolers that leave live foliage alone, ensuring delicate carpet runners and stem leaves stay rooted. While they look clean through front aquarium glass, Medakas have a long history of being appreciated from above, making Komachis especially well suited for shallow rimless tanks, mini ponds, and outdoor patio tubs where their split color blocking is on full display. Because they feed actively right at the surface and can easily leap when startled, keeping a secure lid on the tank is essential.

**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

• Two-tone orange and milky white pattern creates vivid contrast in both front and top-down views.
• Active top-dwelling nano schooler that stays plant-safe and leaves carpet plants rooted.
• Cold-tolerant and adaptable nature thrives in unheated indoor tanks, heated community setups, or outdoor tubs.

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 into your tank's GH, KH, and pH levels.
• Equip your tank with a snug lid or generous floating plant cover; active Medakas can leap when startled.
• Provide gentle surface circulation; strong filter turbulence can easily exhaust these small surface swimmers.
• Feed crushed flakes, micro pellets, or baby brine shrimp once or twice daily to match their small, upturned mouths.
• Keep in groups of 6 or more to encourage confident schooling behavior and reduce stress.
• Orange marking placement and white density vary naturally between individual fish and intensify under bright 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!

Frequently Asked Questions

1. How do I bring out the best color contrast on Komachi Medakas?

Full-spectrum overhead lighting and a dark background or substrate make the two-tone pattern pop the most. Direct top-down light helps define the line between the milky white body and orange patches. Offering carotenoid-rich foods such as baby brine shrimp, cyclops, and quality spirulina-based micro foods will also help keep the orange patches rich and saturated.

2. Do Komachi Medaka Rice Fish require an aquarium heater?

Not in a standard indoor room. Japanese Medakas are eurythermal and handle wide temperature ranges with ease, thriving at typical room temperatures between 64°F and 74°F without a heater. They also work well in heated community aquariums up to 78°F or unheated outdoor mini ponds in spring and summer.

3. How do Medaka Rice Fish spawn, and how do I raise the fry?

Females produce small bunches of eggs that hang from their vent like tiny grape clusters before they brush them off into floating plant roots or artificial yarn mops. For a complete breakdown of setting up breeding tubs, collecting egg mops, and raising fry, read our Japanese Rice Fish Care Guide.

4. Are Komachi Medakas safe to keep with dwarf shrimp?

Adult Neocaridina and Caridina shrimp are safe to house with them. Medakas stay close to the waterline and have small upturned mouths, rarely interacting with shrimp grazing on hardscape or substrate. Free-swimming newborn shrimplets at the surface can be eaten, so having dense moss and low ground cover provides plenty of protection for your colony.