Blind cave tetra
Astyanax mexicanus
Also known as Mexican tetra
FreshwaterFish
Care at a glance
- Temperature
- 70–77°F
- 21–25°C
- pH
- 6.0–8.0
- Adult size
- 4.7 in
- 12 cm
- Minimum tank
- 25 gal
- 95 L
- Temperament
- Peaceful
- Social behavior
- Social
- Tankmates
- With caution
- Swim level
- Middle
- Difficulty
- Easy
- Breeding
- Medium
- Rarity
- Rare
- Family
- Characidae
- Origin
- Mexico
Overview
The blind cave tetra is an active, social fish for the middle of the tank, and it is easy to care for.
Did you know
The blind cave tetra almost never bumps into things, even with no sight at all. It maps its surroundings by sensing tiny pressure changes in the water with its lateral line. It also holds its own at feeding time right alongside sighted tank mates.
Caring for the blind cave tetra
Blind cave tetras are social and best kept in a group of six or more, in 25 gal (95 L) or larger. They do not need darkness, and rockwork suits their natural setting.
Keep the water stable and well filtered, with some current, at 70 to 77°F (21 to 25°C). They handle a wide pH band, from 6.0 to 8.0. Feed flake, pellets and frozen foods. They find food by smell and with their lateral line, so they need no eyes to eat.
They spend their time in the middle of the tank and are peaceful with their own kind. They are active and can nip, so pair them with similarly bold tank mates rather than timid ones. Breeding them is of medium difficulty.
Good to know
The blind cave tetra is the cave-adapted form of the Mexican tetra, a characin in the family Characidae. The cave form has lost both its eyes and its pigment over generations. The surface form keeps normal eyes and silver color, and the two forms are the same species and can interbreed. Its conservation status is Least Concern.
In the wild
The blind cave tetra lives in dark limestone caves in northeastern Mexico. There is no light there, food is scarce, and the water is cool and roughly neutral.
Common questions
What size tank does a blind cave tetra need?
A blind cave tetra needs at least 25 gal (95 L). It spends most of its time in the middle.
What temperature and pH does a blind cave tetra need?
A blind cave tetra is comfortable at 70–77°F (21–25°C) with a pH of 6.0–8.0.
What does a blind cave tetra eat?
A blind cave tetra eats flake, pellets and frozen foods. It finds its food by smell and with its lateral line, without needing eyes.
How big does a blind cave tetra get?
An adult blind cave tetra reaches about 4.7 in (12 cm).
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