TankBud

Axelrod's glass tetra

Brittanichthys axelrodi

Also known as Red glass tetra, Painted glass tetra

FreshwaterFish

Axelrod's glass tetra (Brittanichthys axelrodi)

Care at a glance

Temperature
75–82°F
24–28°C
pH
4.5–6.2
Adult size
1.3 in
3.3 cm
Minimum tank
14 gal
54 L
Temperament
Peaceful
Social behavior
Schooling
Swim level
Middle
Difficulty
Difficult
Breeding
No record
Rarity
Rare
Family
Characidae
Origin
Rio Negro blackwaters, Brazil

Overview

Axelrod's glass tetra is a tiny, delicate tetra for a quiet blackwater tank. It is a fish for experienced keepers.

Did you know

Axelrod's glass tetra comes from streams that are often near pH 4 in nature.

Caring for the Axelrod's glass tetra

Give a group of Axelrod's glass tetras 14 gal (54 L) or more, in a quiet, dimly lit tank that is mature and stable. Filter over peat or botanicals, and add leaf litter and driftwood for tannins.

It needs genuine blackwater conditions, with very little hardness. Keep the water warm, at 75 to 82°F (24 to 28°C), and hold the pH low, at 4.5 to 6.2. Offer tiny foods such as microworm, baby brine shrimp, cyclops and finely crushed flake.

Keep at least eight to ten together to see natural behavior and steady color. It is entirely peaceful and competes poorly for food, so nothing boisterous or fast should share the tank. Keep it in a species tank or with equally small, gentle fish from the same soft, acidic water, such as cardinal tetras and pencilfish.

It is one of the few tetras that breed by internal insemination. Instead of fertilizing eggs in open water, males transfer sperm directly to females, which can store it. Mature males use tiny bony hooks on the anal fin as contact organs during mating, and they have a distinctively curved caudal-fin ray. Home breeding is essentially undocumented.

Good to know

Axelrod's glass tetra is a characin in the family Characidae. Its genus name honors the ichthyologist Martin Brittan, and its species name honors Herbert Axelrod.

In the wild

Brittanichthys axelrodi comes from the blackwaters of the Rio Negro in Brazil. These tea-stained streams are very soft and strongly acidic.

Weekly picks

Tank mates

The Axelrod's glass tetra is a peaceful, schooling species that keeps to the middle. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.

Check the full mix in the stocking calculator

Common questions

What size tank does an Axelrod's glass tetra need?

An Axelrod's glass tetra needs at least 14 gal (54 L). It spends most of its time in the middle.

What temperature and pH does an Axelrod's glass tetra need?

An Axelrod's glass tetra is comfortable at 75–82°F (24–28°C) with a pH of 4.5–6.2.

What does an Axelrod's glass tetra eat?

An Axelrod's glass tetra eats tiny foods such as microworm, baby brine shrimp, cyclops and finely crushed flake.

How big does an Axelrod's glass tetra get?

An adult Axelrod's glass tetra reaches about 1.3 in (3.3 cm).

Does an Axelrod's glass tetra need a group?

Yes. An Axelrod's glass tetra is a schooling species and should be kept in a group, not singly.

How can you tell a male Axelrod's glass tetra from a female?

Males carry tiny bony hooks on the anal fin and a distinctively curved caudal-fin ray once they mature.

How does an Axelrod's glass tetra breed?

Axelrod's glass tetra breeds by internal insemination, with males passing sperm straight to females, which can store it. Home breeding is essentially undocumented.

Related species