Forktail Rainbowfish (Pseudomugil furcatus)

The Forktail Rainbowfish (Pseudomugil furcatus), also commonly known as the Forktail Blue-eye, is a beautiful small freshwater fish known for its bright yellow fins, blue eyes, and distinctive forked tail. Its energetic swimming behavior and attractive fin displays make it an excellent choice for planted aquariums and peaceful community tanks.

Active, peaceful, and social, the Forktail Rainbowfish looks especially impressive when kept in a proper group. Males frequently display their colorful fins to one another, creating an attractive and lively aquarium display. Good water quality, a varied diet, and suitable aquarium lighting help bring out their best coloration and natural behavior.

What We Like About This Fish

• Beautiful bright yellow fins and distinctive blue eyes
• Unique fork-shaped tail
• Attractive fin displays, especially from males
• Peaceful and active community fish
• Excellent group behavior
• Ideal for planted and natural-style aquariums
• Small size suitable for many community setups

Recommended Tank Parameters

• Tank Size: Minimum 60 liters (15 gallons)
• Temperature: 24–28°C (75–82°F)
• pH: 7.0–8.0
• Water Hardness: Moderate
• Water Flow: Gentle to moderate

A well-planted aquarium with open swimming areas provides an ideal environment for Forktail Rainbowfish. Dense plants around the sides and back of the aquarium provide security, while open areas allow the fish to swim freely and display their attractive fins. A secure aquarium lid is recommended because these active fish may jump.

Care Guidelines

Diet: Omnivorous. Feed high-quality small flakes, micro pellets, and appropriately sized foods supplemented with frozen or live foods such as baby brine shrimp, daphnia, and small bloodworms. Their relatively small mouths should be considered when selecting food size. A varied diet helps maintain healthy growth, activity, and vibrant coloration.

Social Behavior: Peaceful and social. Forktail Rainbowfish should ideally be kept in groups of at least 6, with larger groups encouraging more natural behavior and attractive male displays. They are suitable for peaceful community aquariums with similarly sized, non-aggressive tank mates.

Origin

Oceania – Papua New Guinea

Average Adult Size

Approximately 5–6 cm (2–2.4 inches)

Average Purchase Size

Approximately 2.5-3 cm (1-1.2 inches)

Schooling Fish

Yes. Forktail Rainbowfish are social group-oriented fish and should ideally be kept in groups of at least 6. Larger groups can provide increased confidence and more impressive natural displays.

Shrimp Safe

Mostly yes with adult shrimp. Forktail Rainbowfish can generally coexist with larger adult shrimp. However, very small shrimp and newly hatched shrimplets may be eaten. Dense plants, moss, and hiding areas can help protect young shrimp.

The Forktail Rainbowfish (Pseudomugil furcatus) is an excellent choice for aquarists looking for a small, peaceful, and highly active fish with beautiful coloration. With its brilliant blue eyes, yellow fins, distinctive forked tail, and entertaining display behavior, this attractive species can become a standout feature in a well-planted community aquarium.