Saltwater Aquarist

Mexican Tetra

(Astyanax mexicanus)

Mexican Tetra (Astyanax mexicanus) in a freshwater aquarium

Species Description…

Scientific Name: Astyanax mexicanus
Common Name: Mexican Tetra
Species Group: Tetra
Tank Type: Community
Care Level: Beginner
Temperament: Peaceful
Diet Type: Omnivore
Role in Aquarium: Community Fish
Max Fish Length: 3.7 (inches)
Min Aquarium Size: 19 (gallons)
Native Range: Southern Texas and New Mexico through Mexico to Guatemala. The blind cave form is found only in Mexico.
Min Temperature: 68°F
Max Temperature: 77°F
Min pH: 6.5
Max pH: 8
Min GH: 5 dGH
Max GH: 25 dGH
Min Group Size:
Breeding: Easy
Lifespan: years

Overview

  • The Mexican Tetra (Astyanax mexicanus) is best known in its blind cave form, the blind cave tetra.
  • The species ranges from Texas and New Mexico through Mexico to Guatemala. The eyeless form lives only in Mexican caves.
  • Grows to about 3.7 in (9.5 cm) standard length.

Feeding

  • Feed quality dried foods plus plenty of small live and frozen foods.
  • Finds food by smell and by sensing movement in the water.

Habitat

  • A tank with a base of 31 × 12 in (80 × 30 cm).
  • The blind form needs no special decor. A cave-style rock setup also works well.
  • Water: 68–77°F (20–25°C), pH 6.5–8.0, GH 5–25.

Fish Care

  • Hardy and an excellent choice for beginners.

Compatibility

  • Fits most community tanks.
  • Avoid very shy or slow tankmates. It may bump or nip while searching for food.

Aquarium Behavior

  • Peaceful and active. [UNVERIFIED] Best kept in a group.

Breeding

  • Quite easy.
  • Suspend mesh about 0.5 in (1.3 cm) above the tank bottom so adults can’t eat the eggs.
  • Condition males and females in separate tanks first.