Blind Cave Tetra ~ Astyanax mexicanus

Description & Care Guide:
The Blind Cave Tetra is a fascinating and unique freshwater fish known for its lack of eyesight, a feature that has evolved in the dark, cave-dwelling environment from which it originates. With its pale, almost translucent body and small size, this species is adapted to life in total darkness, relying on other senses such as lateral line detection to navigate. Despite its blindness, the Blind Cave Tetra is a hardy and peaceful fish, making it an interesting addition to community aquariums. It thrives in schools and does well in slightly acidic to neutral water conditions.

• Difficulty Level: Easy

• Tank Size: Minimum 20 gallons

• Food Requirements: Omnivorous – accepts flakes, pellets, and live or frozen foods like bloodworms and daphnia

• Temperament: Peaceful, social; best kept in schools of 6 or more

• Water Parameters: Prefers slightly acidic to neutral water (pH 6.0 - 7.5), temperatures between 68-77°F (20-25°C)

• Full Grown Size: 2-3 inches (5-7 cm)

Wild Habitats/Origins:
The Blind Cave Tetra is native to the caves of Mexico, specifically found in underground rivers and caves where light is minimal or absent. These fish have adapted to their dark environment by losing their eyesight over generations. In the wild, they are found in the cool, oxygen-rich waters of cave systems, where they rely on sensory mechanisms like their lateral line to detect movement and find food.

Fun Fact:
The Blind Cave Tetra’s loss of sight is an incredible example of evolutionary adaptation to cave life. Without eyes, it has developed an enhanced lateral line system that allows it to "feel" the water around it, effectively navigating and foraging in complete darkness.