Filament tetra
Hemigrammus filamentosus
Also known as Phoenix tetra
Care at a glance
- Temperature
- 75–82°F (24–28°C)
- pH
- 5.0–6.8
- Adult size
- 1.7 in (4.3 cm)
- Minimum tank
- 20 gal (75 L)
- Temperament
- Peaceful
- Social behavior
- Schooling
- Swim level
- Middle
- Difficulty
- Medium
- Breeding
- No record
- Rarity
- Common
- Origin
- Araguaia floodplain, Brazil
- Family
- Characidae
Overview
Keep ten or more so males have rivals to display against, which is what keeps the fin extensions on show. A group in a 75 liter blackwater tank with soft water, leaf litter and dim light will spend most of the day sparring harmlessly. Feed small foods it can take mid-water: fine flake, micro granules and frozen cyclops or daphnia. Avoid boisterous tankmates that would damage the trailing fins.
In the wild
Hemigrammus filamentosus lives in the Araguaia floodplain in Brazil, in soft, acidic, often tannin-stained water among vegetation and litter. Keep it at 24 to 28 degrees Celsius and pH 5.0 to 6.8, with gentle flow and subdued light.
Good to know
Hemigrammus filamentosus reaches about 4.3 centimeters. Mature males extend the front rays of the dorsal and anal fins into fine filaments that they raise during display. It is an egg-scattering, non-guarding spawner, and the filaments are the clearest way to sex the species.
Did you know
The trade sells it as the phoenix tetra for the way displaying males seem to trail flame.
Tank mates
Filament tetra is a peaceful, schooling species that keeps to the middle. These picks match on water type, temperature, pH, size and temperament.
Bloodfin tetra
Aphyocharax anisitsiFreshwater2.2 in (5.5 cm)20 gal (75 L)72–82°F (22–28°C)
Forktail spiny loach
Lepidocephalichthys furcatusFreshwater2.4 in (6 cm)20 gal (75 L)73–82°F (23–28°C)
Colombian Tetra
Hyphessobrycon columbianusFreshwater2.6 in (6.5 cm)20 gal (75 L)73–82°F (23–28°C)
Clown pleco
Panaqolus maccusFreshwater3.5 in (9 cm)20 gal (75 L)73–82°F (23–28°C)
Amanda Jane's cory
Brochis amandajaneaFreshwater2.6 in (6.5 cm)20 gal (75 L)75–82°F (24–28°C)
Hoigne's dwarf cichlid
Apistogramma hoigneiFreshwater3 in (7.5 cm)20 gal (75 L)75–84°F (24–29°C)
Common questions
What size tank does a Filament tetra need?
A Filament tetra needs at least 20 gal (75 L). It spends most of its time in the middle.
What temperature and pH do Filament tetra need?
Filament tetra are comfortable at 75–82°F (24–28°C) with a pH of 5.0–6.8.
How big do Filament tetra get?
An adult Filament tetra reaches about 1.7 in (4.3 cm).
Do Filament tetra need a group?
Yes. Filament tetra are a schooling species and should be kept in a group, not singly.
Where to buy
Some links may not be the exact species or variety.
- Aquatic Arts Freshwater fish, shrimp and snails with an arrive-alive guarantee
- The Wet Spot Tropical Fish Large selection of quarantined tropical freshwater fish, with live arrival guarantee and Next Day Air flat rate shipping to all US locations
…or ask your local fish store.
Appears in
Keeping Filament tetra?
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Planning tankmates
See how Filament tetra fits a stocking plan. Open the stocking calculator
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Related species
Ulrey's tetra
Hemigrammus ulreyiFreshwater1.7 in (4.4 cm)20 gal (75 L)72–81°F (22–27°C)
Garnet tetra
Hemigrammus pulcherFreshwater1.8 in (4.5 cm)20 gal (75 L)73–82°F (23–28°C)
Head-and-taillight tetra
Hemigrammus ocelliferFreshwater1.8 in (4.5 cm)17 gal (65 L)75–82°F (24–28°C)
Glowlight tetra
Hemigrammus erythrozonusFreshwater1.6 in (4 cm)18 gal (70 L)75–82°F (24–28°C)
January tetra
Hemigrammus hyanuaryFreshwater1.6 in (4 cm)17 gal (65 L)73–81°F (23–27°C)
Red flush tetra
Hemigrammus stictusFreshwater2 in (5 cm)20 gal (75 L)73–82°F (23–28°C)