Tennyo no Mai Medaka (Oryzias latipes) – Tank-Bred

Species Overview The Tennyo no Mai Medaka (Oryzias latipes), also known as the Heavenly Maiden Dance Ricefish, is a striking long-finned Japanese Ricefish developed by combining the Matsui long-fin trait with a Miyuki base. The result brings together the reflective, metallic appearance associated with Miyuki Medaka and dramatically elongated finnage that gives mature Tennyo no Mai their characteristic flowing appearance. The name Tennyo no Mai (天女の舞) translates approximately to “Dance of the Heavenly Maiden,” inspired by the graceful movement of the fish's extended fins as it swims. Unlike standard-finned Miyuki Medaka, the fins of Tennyo no Mai become increasingly prominent as the fish matures, so younger specimens may not yet display the dramatic finnage seen in fully developed adults. Individual fish can also vary naturally in fin length, body sheen, and overall expression. Despite its elaborate appearance, Tennyo no Mai retains the active, social nature that makes Japanese Ricefish so enjoyable to keep. These tank-bred Medaka spend much of their time near the upper levels of the aquarium and can be kept in planted aquariums, dedicated Medaka displays, and appropriately managed outdoor container setups. Their combination of metallic coloration, flowing finnage, manageable adult size, and peaceful behavior makes Tennyo no Mai a particularly distinctive expression of Oryzias latipes. What We Love About This Fish Flowing Long-Fin Form: The Matsui long-fin trait gives mature Tennyo no Mai their signature extended finnage and graceful movement. Miyuki Metallic Sheen: Their Miyuki heritage contributes the bright silver to blue-white reflective appearance that makes these Medaka beautiful from above or from the side. Gets Better With Maturity: The characteristic finnage continues to develop as Tennyo no Mai grow, making this an especially rewarding variety to raise to adulthood. Peaceful and Social: Their small size and generally peaceful behavior make Tennyo no Mai well suited to planted Medaka displays and carefully selected community aquariums. Quick Care Guide Care Level: Easy to Moderate — Tennyo no Mai Medaka retain the adaptability of Japanese Ricefish, but their elongated fins make clean water, gentle flow, and appropriate tank mates especially important. Temperament: Peaceful — Tennyo no Mai are generally peaceful toward their own kind and other appropriately selected community fish. Diet: Omnivore — Offer a varied diet of high-quality small pellets or flakes along with appropriately sized live and frozen foods such as Daphnia, Moina, and Baby Brine Shrimp. Average Adult Size: 1.25–1.5 inches (3–4 cm) — Their elongated fins can make mature Tennyo no Mai appear larger than standard-finned Medaka of the same body size. Average Purchase Size: Approximately 1–1.5 inches Tank Level: Upper to Middle — Like other Japanese Ricefish, Tennyo no Mai spend much of their time swimming and feeding near the water's surface. Activity Level: Active — These curious ricefish regularly explore open water and planted areas throughout the day. Social Behavior: Social — Tennyo no Mai should be kept with other Medaka rather than as solitary fish, with enough space for individuals to interact without crowding. Shrimp Compatibility: Yes, with adult shrimp — Adult freshwater shrimp are generally safe, although very small shrimplets may be eaten opportunistically. Tank Parameters Minimum Tank Size: 10 gallons — A 10-gallon aquarium provides adequate space for a small group, although larger footprints offer more swimming room and greater water stability. Temperature: 64–78°F (18–26°C) — Tennyo no Mai Medaka are temperate fish and do not require the consistently warm conditions needed by many tropical species. pH: 6.5–8.0 — Japanese Ricefish are adaptable to a relatively broad pH range, but stable conditions are more important than trying to maintain a specific number within that range. GH: 5–20 dGH — Tennyo no Mai tolerate a broad range of mineral content and generally do well in moderately soft to hard water. KH: 2–12 dKH — Some carbonate hardness helps provide buffering and reduces the likelihood of sudden pH changes. Water Flow: Gentle to Moderate — Good filtration and oxygenation are important, but Tennyo no Mai should not have to constantly fight strong current with their elongated fins. Aquarium Cover: Secure lid recommended — Medaka spend considerable time near the surface and are capable jumpers, particularly when startled or during active social interactions.