One of the most interesting Characin, which is naturally blind, is commonly called the "Blind Cave Fish." Thousands of years ago, these fish were carried by currents into underground caves where little or no light existed. Because sight was of no use in the dark environment of the caves, over the course of time nature ceased to provide these useless organs.
Anoptichthys Jordani or the Blind Cave Fish, swim at all depths; even in thickly planted aquariums and rarely bumps into the foliage. The fish are equipped with extremely sensitive organs that warn them of obstacles in their path. It is amazing to see how they change direction to avoid plants, rocks, other fish and the sides of the tank.
This species comes from Mexico—from San Luis Potosi, the southwest part of the drainage basin that receives its water from the Rio Tampaon, at the inlet to the Rio Coy. Since its initial discovery in 1936, numerous other cave locations have been discovered, indicating a quite extensive range of caves this unique species calls home. It was first imported by C. Basil Jordan, a dealer in aquarium fish in Dallas, Texas, in 1936.
When this new species was displayed, it became the newest sensation of the tropical fish world. When people saw that it was obviously blind due to the fact that it had no eyes of any kind, and then saw it swim freely about an aquarium filled with plants, rocks, and other fish yet never colliding with a thing, it became a must have fish. Further, this little gem required virtually no special conditions; it could live at 64 F or be equally happy at 88 F, seemed happy in almost any water conditions and would gladly accept almost any food as well as out scavenged all but the most efficient scavenger.
The actual collector of the first A. Jordani is unknown; however, in a letter received by C. Basil Jordan (who was credited with its discovery), the collector described the natural environment of the Blind Cave Fish.
It is very difficult to realize how impressive are the caves that have been formed in the habitat of this fish in Mexico. After walking about a mile through narrow caverns, blocked here and there by fallen boulders, we came to a space, so far from light that without our electric lanterns it was truly pitch black. We came into a space large enough to contain a cathedral, entirely covered with stalactites and stalagmites. Finally, we came to the first pool where it was clear, by the great number of bones, that not only animals but men as well had become lost here over the ages. It is still a place dreaded by the Indians for its sheer size and total darkness. After many difficulties, and slipping and sliding, we squeezed, with trouble, through narrow openings, past several pools of great depth, and in these pools 100 specimens of Anoptichthys Jordani were caught.
Of the 100 specimens, 75 were sent to Jordan in Texas, and all of them arrived alive. They proved not difficult to keep at all. They accepted all kinds of food as soon as it was offered, and very shortly after arrival, he was successful at breeding them. Almost all Blind Cave Fish found in stores today, can be traced to the original 75 delivered to Dallas in 1936. As Jordan continued to experiment, he found, quite unexpectedly, that the new species was unusually suitable for the aquarium. It reproduced spontaneously without difficulty and adapted itself with the greatest of ease to practically every thinkable aquarium condition.
The fish is brilliant shining silver, the fins being creamy. In large females the first rays of the anal and ventral fins are pink. The fish are equipped with extremely sensitive organs that warn them of obstacles in their path. The blindness is no handicap, for the instant the aquarium cover is raised these docile fish become active and acute; they are first on the food, whether live, frozen, or dried. Should anything edible be given during the hours of darkness, Blind Cave Fish have distinct advantages over all fish with sight.
As scavengers, they are equally as good as the generally recommended catfishes, but where the catfish eat their fill and disappear behind rocks or plants while living exclusively on the bottom of the aquarium, Blind Caves Fish are always in full view front and center dodging and bobbing fish and plants.