Freshwater Fish
Neon Blue Rice Fish
A tiny, shimmering ricefish from Sulawesi, Indonesia with an iridescent blue body and vivid red-orange fin tips. Beginner friendly, breeds readily, and one of the most shrimp-safe fish in the hobby.
Neon Blue Rice Fish (Oryzias woworae), also known as Daisy's Blue Ricefish and named after Indonesian carcinologist Daisy Wowor who first collected and described the species, are a tiny, vividly coloured ricefish (medaka) from the slow-moving streams and ponds of Muna Island in Southeast Sulawesi, Indonesia. The body is translucent with a shimmering iridescent blue-green hue that catches and reflects light as the fish moves, and the fins carry vivid red to orange-red markings that create a warm-cool colour contrast striking for a fish barely 1 inch in length. Males are more intensely coloured than females and develop slightly extended fins. They are exceptionally hardy, beginner friendly, adaptable to a wide range of water parameters, and breed readily in a well-planted setup. One of the most shrimp-compatible fish in the hobby due to their small mouth size and peaceful disposition. Keep in groups of 6 or more in a densely planted tank with dark substrate and floating plants for best colour expression.
6.5–8.0pH
4–18GH (dGH)
72–82°FTemperature
1.2 inMax Size
Appearance & Behaviour
Iridescent Blue with Red-Orange Fins
Translucent body with iridescent blue-green sheen and vivid red to orange-red fin markings. The colouration of O. woworae is most vivid in adult males in good condition. The iridescent blue of the body shifts and glows as the fish moves through light, and the red-orange of the fin edges creates a warm-cool contrast that makes the fish immediately striking despite its tiny size. The colour is most intense in subdued lighting against dark substrate, where the iridescence reads as a glow rather than a surface reflection. Floating plants that diffuse overhead light enhance the effect significantly.
Males more vivid than females -- displaying behaviour between males intensifies colour. Males are noticeably more colourful than females and develop slightly longer dorsal and anal fins. In a mixed group with both sexes present, males display to each other and to females, during which their colour intensifies and the iridescent blue becomes most saturated. Maintaining a ratio of roughly one male to two females reduces competitive stress while keeping display behaviour active.
Top-dwelling and surface-oriented -- active at the upper water level. Neon Blue Rice Fish spend most of their time in the upper third of the water column and at the surface. This surface orientation means they are particularly visible and particularly well-displayed in tanks with floating plants like Frogbit or Salvinia, where the fish weave through the root systems continuously. Their position at the top of the tank complements bottom-dwelling shrimp perfectly without any competition for the same space.
Breeds readily in a planted tank -- females carry egg clusters before depositing them on plants. Female Neon Blue Rice Fish carry fertilised egg clusters attached to their bodies for a period before depositing them on fine-leaved plants and moss. The eggs hatch in 1 to 3 weeks depending on temperature. Adults generally ignore eggs but may consume newly hatched fry. A separate breeding container or dense moss provides fry refuge in a community setup. Breeding is straightforward and occurs without intervention in a well-established planted tank.
Hardy and adaptable -- one of the most parameter-tolerant ricefish available. O. woworae tolerates a wide range of pH, hardness, and temperature. It is also uniquely tolerant of varying salinity, thriving in freshwater, low-salinity brackish, and reportedly even fully marine conditions. In a standard freshwater planted tank it is among the most forgiving and least demanding nano fish available, making it well-suited to beginner and experienced keepers alike.
Shrimp Compatibility
Exceptionally Shrimp Safe
Tiny mouth -- adult Neocaridina and Caridina shrimp are completely safe. The mouths of O. woworae are extremely small relative to body size. Adult shrimp are well beyond what the fish can consume. Only the very smallest newly hatched shrimplets in their first days of life are at any risk, and in a planted tank with Java Moss or Subwassertang the survival rate of shrimplets alongside Neon Blue Rice Fish is very high. They are widely recommended as one of the safest fish for shrimp breeding tanks.
Surface-dwelling habit means minimal interaction with substrate-level shrimp. Because Neon Blue Rice Fish occupy the upper water column and shrimp spend most of their time at the substrate and hardscape level, the two species rarely interact. This natural vertical separation further reduces any predation risk and means the two animals essentially share the tank without competing for the same space at any point.
Wide parameter tolerance overlaps well with both Neocaridina and Caridina. The broad parameter range of O. woworae means it can be kept comfortably in standard Neocaridina water (pH 6.8 to 7.8) and in softer, slightly acidic Caridina setups alike. No water chemistry compromise is required to keep both species together in either parameter range.
Keeper's NoteA group of 10 Neon Blue Rice Fish in a planted shrimp tank with floating Frogbit, dark substrate, and Java Moss creates one of the most complete and most visually layered nano tank displays available. The fish work the surface and upper water; the shrimp work the substrate and hardscape below. The iridescent blue of the fish catches the light filtering through the floating plant roots above; the shrimp colours read against the dark substrate below. The two animals never compete and never conflict, and the result is a tank that is visually interesting at every level simultaneously. Feed small foods twice daily and the Neon Blue Rice Fish will breed on their own without any further intervention.
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