Javanese Ricefish – Cuboid Nature Aquarium

Javanese Ricefish

Javanese Ricefish(Oryzias javanicus) is the standard wild-type form — a pale olive-silver body with subtle iridescent scaling and the characteristic upturned mouth and flat-backed profile of the Oryzias genus. The Javanese Ricefish is a distinct species from the Japanese Medaka — a Southeast Asian member of the same genus with a more tropical distribution and slightly different care requirements.

Feeding & Care Tip:Hikari Micro Pellets(crushed or soaked briefly) andSera Vipan Babymake excellent daily staples — the small particle size suits medaka’s small upturned mouth. Supplement 2–3× per week withHikari Frozen or Freeze-Dried Baby Brine ShrimpandHikari Frozen Daphnia. Medaka are surface-oriented feeders — floating or slow-sinking foods work best. Feed small amounts 2–3 times daily.

Native to rivers, estuaries, and coastal streams of Java, Sumatra, and surrounding Southeast Asian islands — a more tropical and slightly brackish-tolerant species than the Japanese Medaka.Oryzias javanicusis a distinct species fromO. latipes, hardier at warmer temperatures and adaptable to a wider salinity range from fresh to slightly brackish water.

Keep in groups of at least six. Peaceful with all small, peaceful community species. More warmth-tolerant than Japanese Medaka — does not share the cold-water hardiness ofO. latipes. Adapts well to hard, slightly alkaline freshwater.

Medaka are egg-scatterers that breed readily with minimal encouragement. Females carry fertilized eggs attached to their belly for a short period before depositing them on plants or a spawning mop. Eggs hatch in 7–14 days depending on temperature. Fry are tiny but immediately free-swimming and can take crushed fine food from day one. In a planted outdoor tub, multiple generations can coexist through the season.

Care & Ideal Parameters