Cave tetra

Astyanax jordani is a freshwater fish of the Characin family (family Characidae) of order Characiformes, native to Mexico. It is often referred to by its local Spanish name Sardina Ciega but is more commonly called the Cave tetra.

A blind cave fish, A. jordani is a recent evolution from the Mexican tetra (A. mexicanus). While it can be confused with the blind cave form of A. mexicanus, it evolved separately from the surface form, and is considered a different species. (IUCN, however, treats it as a subspecies of A. mexicanus.).

This characin is listed on the IUCN Red List as Vulnerable on the basis of shrinking population and an acutely-restricted and diminishing area of occupancy. It is fairly resilient, however, having a population doubling time of 15 months. There are reports that it has been introduced to the Philippines.