Moderate

Threadfin Rainbowfish

By The Aquarium Calculators Editorial Team ·

Iriatherina werneri

Complete Threadfin Rainbowfish care guide covering omnivore diet requirements, peaceful temperament, minimum 15 Gallons tank setup, and compatible freshwater tankmates. Difficulty: Moderate.

Threadfin Rainbowfish

Quick Answer

Threadfin Rainbowfish (Iriatherina werneri) is a delicate, graceful species. It requires a minimum 15 Gallons aquarium with a pH of 6.0 - 7.0 and temperature range of 24-28°C. This omnivore occupies the top/middle zone and makes an excellent addition to community setups.

Intro

Threadfin Rainbowfish (Iriatherina werneri) is a delicate, graceful species. Males have elongated fin rays that trail behind them like threads.

Setup

A 15-gallon or larger tank with dense planting, dark substrate, and gentle filtration. They need soft, slightly acidic water. A tight lid is essential.

Feeding

Omnivorous; accepts micro flakes, baby brine shrimp, daphnia, and finely crushed pellets. They have small mouths.

Compatibility

Peaceful and shy. Keep in schools of 8+. Good with other small, peaceful fish: celestial pearl danios, small tetras, rasboras, and dwarf shrimp.

Aquarium Fish Stocking Calculator

Enter your details below for an instant recommendation.

Recommended Output

Search results

--

Stocking list container

--

Unique count badge

--

Total bioload val

--

Max capacity val

--

Stocking percent

--

Stocking status badge

--

Aggression status badge

--

Turnover recommend val

--

Top layer pct

--

Mid layer pct

--

Bottom layer pct

--

Advisor warnings box

--

Tank Position
Top/Middle
Water Temp
24-28°C
Adult Size
See profile
Water pH
6.0 - 7.0

Species Characteristics

Adult Size
Lifespan
Growth Rate
moderate
Tank Compatibility
Community compatible
Indoor Aquarium
Yes

Water Parameters

Water Temperature
Humidity
Water pH

Tank Lighting

Tank Lighting
Standard lighting
Light Hours
N/A
Intensity
moderate

Feeding & Diet

Diet Type
Diet: Omnivore
Feeding Schedule
N/A
Live Food Options
N/A

Continue Learning

Recommended Tools

Fish Compatibility Calculator fish compatibility

Health & Disease

Ich (White Spot Disease) common disease • all fish

Related Guides

Understanding pH in Aquariums water parameters • ph

Similar Species

African Leaf Fish Care Guide: Diet & Tank Mates semanticSimilarity Angelfish Care Guide: Tank Size & Diet | The Aquarium Calculators semanticSimilarity Badis Care Guide: Tank Size & Compatibility semanticSimilarity

Frequently Asked Questions

How many Threadfin Rainbowfish should be kept together?
Maintain a minimum school of 8 to 12 individuals in a tank of at least 15 gallons (57 liters) with a footprint of 24x12 inches (60x30 cm). Threadfin rainbowfish (Iriatherina werneri) males display elaborate, feather-like fin extensions and vibrant colors only when kept in a school with multiple females. Groups under 6 cause faded colors and fin-nipping. Maintain a 1 male to 2-3 female ratio. Provide densely planted tanks (Java moss, Cabomba), low filter currents, and dark substrate. Tank height should be 12-15 inches (30-38 cm).
What are the exact water parameters for Threadfin Rainbowfish?
Target pH 6.0 - 7.0, General Hardness 3 - 8 dGH, Carbonate Hardness 2 - 6 dKH, Total Dissolved Solids 60 - 150 ppm, Electrical Conductivity 120 - 300 μS/cm, and temperature 75°F - 82°F (24°C - 28°C). They prefer soft, slightly acidic water parameters with low filter currents and dense planted boundaries. Maintain nitrates below 10 ppm with weekly 20% water changes. Use a sponge filter with baffled outflow. Add driftwood and Indian almond leaves. Hardness above 10 dGH reduces fin extension.
What is the dietary and medication protocol for Threadfin Rainbowfish?
They have very narrow throats, requiring 40% protein, 12% fat, 48% plant matter. Feed finely powdered flakes, micro-pellets (0.3 mm), live baby brine shrimp, frozen cyclops, and daphnia 3 times daily. They ignore large pellets. Medication alert: Sensitive to copper (0.1 mg/L max) and formalin. Use malachite green at quarter dose (0.025 mg/L). Praziquantel is safe. Avoid salt (tolerance <2 ppt). Quarantine with methylene blue at half-strength.
How to breed Threadfin Rainbowfish in captivity?
Condition 12-15 fish (1 male:2 female) with live baby brine shrimp and blackworms for 3 weeks. Set up a 10-gallon (38 liter) breeding tank with 6 inches (15 cm) of water (pH 6.5, dGH 5, 78°F/25.5°C), a spawning mop (acrylic yarn), and java moss. Spawning occurs daily at dawn; females deposit 5-15 eggs per day on the mop. Remove parents every 2-3 days. Eggs hatch in 10-14 days at 75°F (24°C). Fry are 0.15 inches (4 mm); feed infusoria for 3 days, then microworms, then baby brine shrimp. Keep tank covered.

Related Content

fish

African Butterflyfish

Complete African Butterflyfish care guide covering carnivore diet requirements, semi-aggressive temperament, minimum 30 Gallons tank setup, and compatible freshwater tankmates. Difficulty: Advanced.

fish

African Cichlid

Complete African Cichlid care guide covering omnivore diet requirements, aggressive temperament, minimum 55 Gallons tank setup, and compatible freshwater tankmates. Difficulty: Advanced.

fish

African Leaf Fish

Complete African Leaf Fish care guide covering carnivore diet requirements, semi-aggressive temperament, minimum 55 Gallons tank setup, and compatible freshwater tankmates. Difficulty: Moderate.

fish

African Red Eyed Tetra

Complete African Red Eyed Tetra care guide covering omnivore diet requirements, peaceful temperament, minimum 30 Gallons tank setup, and compatible freshwater tankmates. Difficulty: Easy.

fish

Angelfish

Complete Angelfish care guide covering omnivore diet requirements, semi-aggressive temperament, minimum 30 Gallons tank setup, and compatible freshwater tankmates. Difficulty: Moderate.

fish

Apistogramma

Complete Apistogramma care guide covering omnivore diet requirements, peaceful temperament, minimum 20 Gallons tank setup, and compatible freshwater tankmates. Difficulty: Easy.