Threadfin Rainbowfish
Iriatherina werneri
Family: Melanotaeniidae • Origin: Oceania
Male Threadfin Rainbowfish have spectacular elongated filaments on their fins. One of the most elegant small fish available.
Min Tank
15 gal
Max Size
2"
Temperature
75-82°F
pH
5.5-7.5
Lifespan
4 years
School Size
6+
Swim Level
middle
Hardness
2-10 dGH
peacefulintermediateomnivoreschooling
Care Tips
- • Males have stunning fin filaments
- • Avoid all fin-nippers
- • Very small mouth — needs micro foods
- • Keep in groups of 6+
- • Gentle current preferred
Feeding: Micro foods: crushed flakes, baby brine shrimp. Very small mouth.
Compatibility Notes: Males have extremely delicate thread-like fins. Avoid ALL fin-nippers. Best with gentle nano species.
Tank Setup & Water Parameters
Tank Requirements
- Minimum Tank Size
- 15 gallons
- Recommended Tank Size
- 20 gallons
- Swimming Level
- middle
- Minimum School Size
- 6+ fish
Water Parameters
- Temperature
- 75–82°F
- pH Range
- 5.5–7.5
- Hardness (dGH)
- 2–10
- Water Type
- freshwater
Behavior & Temperament
- Temperament
- peaceful
- Aggression Level
- 1/5
- Schooling
- Yes
- Territorial
- No
- Fin Nipper
- No
- Predatory
- No
- Diet Type
- omnivore
- Growth Rate
- slow
Males have extremely delicate thread-like fins. Avoid ALL fin-nippers. Best with gentle nano species.
Breeding
- Breeding Type
- egg layer
- Breeding Difficulty
- moderate
- Lifespan
- 4 years
Ideal For
15 gallonplanted tanknano community
Compatible Tank Mates
View all →
Neon Tetra
Paracheirodon innesi
70-81°FpH 6-710+ gal
peacefulschooling 6+1.5"
Cardinal Tetra
Paracheirodon axelrodi
73-81°FpH 4.5-6.510+ gal
peacefulschooling 6+2"
Ember Tetra
Hyphessobrycon amandae
73-84°FpH 5.5-75+ gal
peacefulschooling 8+0.8"
Rummy Nose Tetra
Hemigrammus rhodostomus
75-84°FpH 5.5-720+ gal
peacefulschooling 6+2.5"
Black Neon Tetra
Hyphessobrycon herbertaxelrodi
73-81°FpH 5.5-7.510+ gal
peacefulschooling 6+1.6"
Black Skirt Tetra
Gymnocorymbus ternetzi
70-82°FpH 6-7.515+ gal
peacefulschooling 5+3"
Similar Species
Celebes Rainbowfish
Marosatherina ladigesi
72-82°FpH 7-810+ gal
peacefulschooling 6+3"
Celebes Rainbow
Marosatherina ladigesi
72-82°FpH 7-810+ gal
peacefulschooling 6+3"
Neon Dwarf Rainbowfish
Melanotaenia praecox
72-82°FpH 6.5-7.510+ gal
peacefulschooling 6+3"
Australian Rainbowfish
Melanotaenia fluviatilis
68-77°FpH 7-820+ gal
peacefulschooling 6+4"