Blind Cave Fish

Scientific Name(s): Astyanax fasciatus mexicanus

Common Name(s): Blind Cave Fish, Mexican Tetra, Blind Cave Tetra, Blind Tetra



Origin: Texas, Mexico, Central America to Panama

Family: Characidae

Species Type: Tetra

Maximum Size: 4.7 inches (12 cm)

Life Span: 5-7 years (10+ if well cared for)

Natural Habitat: underground lakes (caves) of Central America.

Diet: Like most omnivores, these fish enjoy a wide variety of floating and sinking foods. Live, frozen, freeze dried blood worms, flakes, small pellets and insects will be happily consumed. Even though they are blind, they have no problems navigating or locating food by using their lateral lines, which are highly sensitive to fluctuating water pressure, plus, they have taste buds all over their heads.

Temperature: 68°-77° F (20°-25° C)

PH: 6.0-7.8

Hardness: up to 30 dGH

Minimum Tank Size: 30 gallon

Tank Region: Mid level dweller

Temperament: Peaceful. When first introduced to a new aquarium they may nip at the fins of their tankmates. When they get used to their new environment this normally stops.

Possible Tank Mates: Semi-aggressive community fish are recommended. The Blind Cave Fish is incredibly fast, and has no problem locating food quickly. This may hamper slower, less aggressive tankmates when feeding.

Setup: Mimicking their natural environment with a gravel bottom, artificial or natural rock and subdued lighting is appreciated.

Coloration: Cream and pink colored with some darker pigment showing through the skin where the eye sockets are.

Breeding: Egg layer. Choose a pair, females are plumper than the slender males. Condition them with live or frozen foods for 10-14 days, lower the temperature to 66°-68° F (19°-20° C) and you will soon see eggs scatter throughout the breeding tank.

The eggs are sensitive to handling so they should not be removed. The fry should hatch in a few days and will initially feed from their yolk sac. Two to three days later when they start free swimming, they should be offered baby brine shrimp and other small foods including finely crushed flake food. Surprisingly, Cave Fish fry are born with eyes that disappear as they mature.

Comments: The taxonomy of the blind cave fish is under review. It may be a separate species of Astyanax rather than a subspecies of Astyanax fasciatus.