OSTEICHTHYES: CHARACIFORMES: CHARACIDAE: Astyanax

Astyanax fasciatus (Cuvier)

Blind cavefish

Photo & text by Dr. Robert Sprackland.

   
Photo taken at Field Museum of Natural History, Chicago.

Range: Caves in Texas south to Argentina.

Diagnosis:

Description:

Natural History: Cave fishes live in a light-free world, an evolutionary adaptation that is apparently recent. Populations of "cave fish" with normal eyes will, when bred under lightless conditions, quickly produce pinkish, eyeless offspring.

Cave fishes live in places where food variety is uneven, hence they are dietarily catholic. Aquarium specimens should be fed dry and small live foods, and some soft algae.

This is the only genus of the family Characidae that occurs in the United States.

Reproduction: Lays eggs, which are fertilized as the female is being chased by the male. Young hatch in 2-3 days and begin free swimming after about a week. Adults will eat both eggs and young.

Taxonomy & Relationships:

Variation:

Additional Comments:

Type Specimen:

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