The Mexican tetra (Astyanax mexicanus) is one of the fresh water teleost fish models in evolutionary developmental biology. The existence of two morphs: eyed, pigmented surface fish and blind depigmented cavefish from multiple cave populations, provides a unique system to study adaptive radiation. Inhabits rocky and sandy bottoms of pools and backwaters of creeks and small to large rivers, and springs. Feeds on insects, crustaceans and worms.
| Scientific Name | Common Name | Size | Temperament |
| Astyanax mexicanus | Mexican tetra | 120mm | Peaceful |
| Water Temperature | Water pH | Tank Size | Diet |
| 20-25°C | 6.5–8.0 | 100 liters | Omnivore |
| Lifespan | Care | Difficulty Breeding | Min Population |
| 3-5 Years | Easy | Difficult | 5 |
| Robustness | Way of Living | Sociability | Availability |
| Hardy | Diurnal | Schoaling | Rare |