Youkihi Medaka Ricefish (Oryzias latipes, “Youkihi”)

The Youkihi Medaka Ricefish (Oryzias latipes "Youkihi") is a variety of the Japanese Ricefish that is highly prized for its beautiful, vibrant coloration and unique appearance. These fish are a variant of the Oryzias latipes species, and like other Medaka ricefish, they are relatively hardy and adaptable. "Youkihi" is a specific strain of Medaka that has a distinct appearance, often showcasing a beautiful golden-orange or red coloration.

Here is a comprehensive care guide for the Youkihi Medaka Ricefish:

Tank Setup

• Tank Size: The Youkihi Medaka is a small fish, generally reaching about 2-2.5 inches (5-6 cm) in length. A tank size of at least 10-20 gallons is ideal for a group of 6-8 fish, though larger tanks are better to ensure stable water conditions and provide plenty of space for swimming.
• Water Conditions:
  • pH: They prefer slightly acidic to neutral water, with a pH range of 6.5-7.5.
  • Temperature: This strain of Medaka is a cold-water species that can tolerate a temperature range of 64-77°F (18-25°C), making them suitable for temperate aquariums. They can handle cooler water compared to many tropical species.
  • Hardness: They prefer soft to moderately hard water, ideally around 5-15 dGH.
• Filtration: Use a gentle filtration system. Since Youkihi Medaka are small and prefer calmer waters, avoid strong currents. A sponge filter or a low-flow canister filter is best to maintain water quality.
• Aquascaping: Provide a well-planted tank with plenty of hiding spots. They enjoy dense Java moss, cryptocoryne, anubias, or Amazon sword plants. Some floating plants can also help dim the light intensity, mimicking their natural environment in rice paddies.
  • Substrate: A fine gravel or sand substrate is ideal, as it resembles their natural environment and is gentle on their small bodies.

Diet

The Youkihi Medaka is an omnivore, and its diet should consist of a variety of foods to ensure optimal health:

• Flake and Pellet Foods: They will happily accept small flake foods or micro pellets made for small fish. Ensure that the food is small enough for them to eat.
• Frozen and Live Foods: Supplement their diet with live or frozen foods such as brine shrimp, daphnia, bloodworms, micro worms, and infusoria. These foods provide a good source of protein and nutrition.
• Vegetables: Although they do not need vegetables regularly, they will enjoy the occasional blanched spinach, zucchini, or peas.
• Feeding Frequency: Feed 1-2 times a day, providing only as much as they can consume in 2-3 minutes. Overfeeding can lead to poor water quality and health issues.

Tank Mates

Youkihi Medaka are peaceful and do well in community tanks with other small, non-aggressive fish. Suitable tank mates include:

• Small peaceful fish: Species such as Neon Tetras, Rasboras, Endler’s Livebearers, and Corydoras catfish work well.
• Shrimp and Snails: They are compatible with small shrimp (like Amano shrimp or Ghost shrimp) and snails (such as Nerite snails or Ramshorn snails).
• Avoid: Larger or more aggressive species like Betta fish, Cichlids, or larger goldfish should be avoided as they can be too aggressive for these peaceful fish.

Water Quality

Maintaining high water quality is essential for Youkihi Medaka:

• Regular Water Changes: Perform 25-30% water changes weekly to maintain good water quality and ensure the health of the fish.
• Ammonia and Nitrites: Always keep ammonia and nitrites at 0 ppm as they are toxic to fish. Nitrates should ideally be kept below 20 ppm.
• Oxygenation: Medaka enjoy well-oxygenated water. A sponge filter or gentle surface agitation will help ensure proper oxygenation without creating too much current.
• Water Testing: Regularly test the water for pH, ammonia, nitrite, and nitrate levels to ensure the environment is stable and suitable for the fish.

Health and Common Issues

Although Youkihi Medaka are generally hardy, they can still be prone to some common fish diseases:

• Ich (White Spot Disease): A common parasitic infection that presents as small white spots on the body. Treat with aquarium salt or medications designed for Ich.
• Swim Bladder Disease: This condition can result from overfeeding or improper diet. Fasting for a couple of days and providing a varied diet can help resolve this issue.
• Fin Rot: Poor water quality can lead to fin rot. This condition is often treated by improving water conditions and using antibiotics if necessary.
• Velvet Disease: A parasitic infection that causes a golden or rusty-colored sheen on the fish. It can be treated with copper-based medications.
• Fungal Infections: Often caused by poor water quality or injury, fungal infections can be treated with antifungal medications.

Behavior and Socialization

Youkihi Medaka are peaceful and social fish that do well in schools. They are best kept in groups of at least 6-8 individuals. Keeping them in groups helps to reduce stress and promotes natural behavior.

• Active Swimmers: They are active swimmers and spend most of their time in the mid to upper regions of the tank.
• Shy but Sociable: While they may be initially shy in a new environment, they will become more confident as they settle in. They are peaceful with one another and with other compatible species.
• Daytime Activity: Like most Medaka, Youkihi Medaka are diurnal and active during the day, especially in the morning and late afternoon.

Lifespan

Youkihi Medaka typically live for about 2-5 years with proper care, although some may live longer under optimal conditions.

Breeding Youkihi Medaka

Breeding Youkihi Medaka is relatively easy, as they are egg layers. Here’s how to breed them:

• Breeding Tank: Set up a separate breeding tank with soft, slightly acidic water (pH 6.5-7.0). Provide plants like Java moss, moss balls, or other soft plants to give the female a place to lay her eggs.
• Spawning Behavior: Male Youkihi Medaka will chase the female, and the female will lay eggs on plants or surfaces. Males fertilize the eggs after they are laid.
• Egg Care: Once the eggs are laid, the adults should be removed from the tank, as they may eat the eggs. The eggs will hatch in 2-3 days depending on temperature.
• Fry Care: The fry will be tiny and require infusoria or liquid fry food until they grow large enough to eat baby brine shrimp. You can also offer finely crushed flakes once they grow bigger.

Conclusion

The Youkihi Medaka Ricefish is a beautiful and hardy species that makes an excellent addition to a peaceful community tank. They are easy to care for, making them suitable for both beginners and experienced aquarists. With proper water conditions, a varied diet, and a peaceful environment, your Youkihi Medaka will thrive and add beauty and activity to your aquarium. Their peaceful nature and attractive coloration make them a joy to keep in the right setup.