Blind Cave Tetra (Astyanax mexicanus)
A fascinating eyeless tetra adapted to life in complete darkness
The Blind Cave Tetra is a unique and hardy species known for its lack of eyes and pale, almost translucent body. Evolved from surface-dwelling ancestors, this cave-dwelling form relies on heightened senses and lateral line detection to navigate and find food, making it an incredibly interesting fish to observe.
Active and constantly on the move, Blind Cave Tetras are best kept in groups where they display natural schooling behaviour. Despite their unusual appearance, they are robust and easy to care for, making them a great choice for both beginner and experienced aquarists. Best suited to community tanks with similarly active fish.
| Specifications |
|---|
| Species: Astyanax mexicanus |
| Size: 2.5 inches (6 cm) |
| Water Temperature: 72-78°F (22-26°C) |
| Water pH: 6.0–7.0 |
| Hardness: 2–8 dGH |
| Group Size: 6 or more |
| Lifespan: 5–8 years |
FAQ
What is the ideal tank size for Blind Cave Tetras?
A minimum of 20 gallons is recommended to accommodate their active schooling behavior and provide enough space for natural movement.
Do Blind Cave Tetras require special lighting?
No, they thrive in low-light or dark environments, as they are adapted to life in complete darkness.
Are Blind Cave Tetras compatible with other fish?
They are best kept with similarly active, non-aggressive community fish that do not chase or nip at them.
Neil McLean –
The Blind Cave Tetras are absolutely mesmerizing. They move gracefully in groups and their lack of eyes makes them a standout in any tank. I’ve had them for six months and they’re still active and healthy. Perfect for someone interested in unique, low-maintenance fish.
Matt Morrison –
First time keeping cave fish, and I’m impressed. They don’t need much in terms of water parameters and are easy to maintain. Just make sure the tank has enough space and other active fish to keep them happy.
Trevor Langdon –
The schooling behavior is incredible to watch. They swim in tight formations and seem to communicate through body movements. I love the contrast with my regular tetras and the tank looks more dynamic now.