OSTEICHTHYES: CHARACIFORMES: CHARACIDAE: Astyanax

Astyanax mexicanus (De Filippi, 1853)

Blind cave tetra

Photo and text by Dr. Robert Sprackland.

Range: Southern Texas south into Argentina.

Diagnosis: A compressed pink fish with clear fins, no external eyes, and an adipose fin.

Description: Grows to 93 mm.

Natural History: This is a cave dwelling fish that has lost its eyes during its evolution in a totally dark environment. The lateral line system and sense of smell are both extremely well developed.

Blind cave tetras are popular in the aquarium hobby and are relatively easy to maintain and breed. They do not require a dark aquarium in order to thrive.

Reproduction: Lays eggs. Incubation takes 3 to 4 days, and fry become free swimming around day seven.

Taxonomy & Relationships: Several related species in tropical America, the others having functional eyes and body pigmentation.

Variation:

Additional Comments:

Type Specimen: Syntypes: MZUT 159(3), ZMUC 941-942(2).

Literature: