A very rare blind catfish species formerly known to live only in Mexico has been found in an underwater cave in Texas.

The live fish, seen in a deep limestone cave back in May at Amistad National Recreation Area near Del Rio, were identified as the Mexican blindcat or the Prietella phreatophila.

This small pair’s species was confirmed by ichthyology curator Dean Hendrickson of the University of Texas at Austin, and they have been brought inside the San Antonio Zoo.

Potential Connection Between Texas-Mexico Sections Of Aquifer

The discovery supports the belief that watery caves below the Rio Grande basin in Texas and Northern Mexican state Coahuila may connect the American state and Mexican parts of the Edwards-Trinity Aquifer, which is the fish’s only known dwelling so far.

Hendrickson said that rumors of blind and white catfishes being spotted in the area have been swirling since the 1960s — yet this is the first confirmed sighting of the species.

“I’ve seen more of these things than anybody, and these specimens look just the ones from Mexico,” he said.

Back in April 2015, Jack Johnson, resource manager for the Amistad National Park Service, first saw a number of the eyeless fish. From there he worked with a team of biologists to find more of the fish last month.

Eyeless Fish Species

The endangered Mexican blindcat is slow-swimming, grows up to 3 inches long, and maintains a light pink hue because its blood is visible through its translucent skin. It exists in groundwater exclusively.

Where the cave-dwelling species reside, eyes, speed, and pigmentation do not appear to be necessary like they would be in surface creatures, as these fish have evolved abilities to successfully inhabit total darkness.

This species was described originally back in 1954, a time when it was detected in springs and wells in Coahuila. Afterwards it was deemed endangered by the government of Mexico and the U.S. Fish and Wildlife Service (FWS), and was sought out in multiple expeditions in Texas and Mexico.

Threats And Opportunities

The findings lead the total number of blind catfish species in the U.S. to three, all discovered in Texas. The newly spotted fish joins the toothless blindcat and the widemouth blindcat, which both reside in Edwards Aquifer.

Johnson warned that aquifer systems supporting this unique fish are facing threats and challenges from contamination and the excessive pumping of groundwater. A look into the condition of the Amistad fish will lend insight into the overall condition of the aquifer along with related water resources.

The fish have not been made available for public viewing and will be kept alive in a special facility that can accommodate aquifer and cave species at the zoo.