Home | Aquarium Livestock | Blind Cave Fish: Their Discovery, Initial Collection and Care – Part 2

Blind Cave Fish: Their Discovery, Initial Collection and Care – Part 2

Blind Cave Fish

Click here to read the first part of Blind Cave Fish
Blind cave fish navigate entirely through the use of the lateral line – a system of sensory organs possessed by all fish but, it seems, very highly developed in this species. The movement of water (caused by currents or the fishes’ own swimming) bouncing off objects is sensed and used to guide the fish in their travels. I am tempted to compare the process to echo-location in bats, or the use of electricity by the elephant nose fish, Gnathonemus petersi, but it is, of course, quite distinct. If you have an opportunity, observe how well cave fish can move about – in an exhibit at the NY Aquarium they speed through a series of glass barriers unerringly. Individuals introduced to new exhibits may “crash” on occasion, so there may be some learning involved as well.

They are also amazingly adept at locating food – a school I kept at the Prospect Park Zoo in NYC hit food dropped on the water’s surface as quickly as do most sighted fish. In fact, blind cave fish do quite well in aquariums housing other fish species.

Recently (January, 2008) it was discovered that young blind cave fish can detect light via unique compounds in the brain’s pineal gland (the embryos begin to develop eyes, but these degenerate rapidly). This ability declines with age.

In contrast to most cave-adapted fish – which require cold, hard water if they are to thrive – blind cave fish are quite undemanding pets. In fact, they do best at 78-82 F, as their native waters are quite warm. If kept alone, slightly hard water should be provided, but they adapt easily to conditions suited to most community-type tropical fish. Despite a very specific natural diet (see above), blind cave fish remain healthy on almost any commercial fish food – I have successfully used a mix of omnivore flakes and pellets, along with frozen foods. They ravenously devour black worms, brine shrimp and such, and are especially fond of crushed crickets and other insects. Their reaction to insect food brings, at least to my mind, an image of feeding behavior in their native cave. At feeding time, they compete quite well with other fish and rarely require special attention.

Blind cave fish are placed within the order Charachiformes, an extremely diverse group of fishes containing well over 1,500 species, including tetras and the infamous piranha. I will write about piranhas in a future article, and will include photos of some that became “attached” to me while I was seining for knife fish in northern South America. Until then, please forward your comments and questions. Thank you. Until next time, Frank.

A fascinating account of the first expedition to collect blind cave fishes, including original drawings and photos, is given in Zoo Expeditions, by William Bridges (William Morrow & Co., 1945). Long out of print, this book is well worth searching for.

An interesting article on the evolution of eye regression in this fish is posted at:

Thanks Frank,

Until Next Time,


  1. avatar

    Hello, I’m interested in starting with blind cave fish andhave a source. Are any species better than others to keep in the same aquarium with them..I read your article concerning the fact that they compete well, but just wondering if some are better than others. It was interesting to read the unusual story of how they arrived in the trade,thanks! A friend keeps Mexican walking fish (really a salamander) and says they have a similar history because there are few left in the wild but many people keep them as pets.

  2. avatar

    Hello, Frank Indiviglio here. Thanks for your interest in our blog.
    Danios, zebras and other fast moving surface feeders would give the cave fish the most competition for food; others that feed at all levels, i.e. swords, plays and typical community fish are usually fine but do feed in the same manner as cave fish, so limit their numbers. Ideal tank mates would be peaceful bottom dwellers that accept greens or pellets and tablets as food, i.e. various loaches, algae eaters, armored and “sucker” catfish, as well as snails and shrimp. Specialized predators that will not attack the cave fish are also a possibility, i.e. small fire eels, African butterfly fish. They will also do well with dwarf African clawed frogs, Hymenochirus spp. (note: do not keep with the larger species Xenopus laevis, as they will harass or consume the cave fishes…please write in for further details if you are interested)
    Your friend is quite right….the “Mexican walking fish” is actually an aquatic salamander known as the Mexican axolotl, Ambystoma mexicanum. Originally native to only 2 lakes near Mexico City, they are now nearly extinct in the wild, yet are extremely common in the pet trade and, oddly enough, have been valuable laboratory animals for over 100 years. Many aquarists find them an interesting introduction to amphibian-keeping. If you’d like to read more about them, please see my article at: http://blogs.thatpetplace.com/thatreptileblog/2008/12/19/the-natural-history-and-captive-care-of-the-mexican-axolotl-ambystoma-mexicanum-natural-history-part-1/.
    Best regards, Frank Indiviglio.

  3. avatar

    Hello, I wrote in in the past about frogs and blind cave fish. I started looking at frogs and reading and am interested in them. I’m confused about telling the difference between the 2 that you mentioned, one pet store says they are that young ones are called dwarfs, another says they are different species. The articles I have found show several species of African frogs but I’m not sure how I can tell which is the one you recommended (dwarf) by sight. Any info would be great , thankyou.

  4. avatar

    Hello, Frank Indiviglio here. Thanks for your interest in our blog.

    The aquatic frog most often seen in pet stores is the larger species, known as the African clawed frog, Xenopus laevis. Females can reach 8 inches in length; they make wonderful, long-lived pets (I kept 1 for over 17 years) but harass or consume most fish. Small ones are common in the and often sold as “dwarf frogs”. You should not mix this frog with your cave fish. There are 17 other species in the Genus, 1-2 of which sometimes show up as well.

    The true dwarf clawed frog, Hymenochirus boettgeri (and 3 similar species) reaches only 1-1.5 inches in length. The easiest way to distinguish it from a small Xenopus is to examine the front feet. The dwarf clawed frog has webbed front (and rear) feet, or “hands”. In Xenopus, only the rear feet are webbed. Dwarf frogs are also more flattened in appearance, and have pointed heads.

    Dwarf frogs do well in groups, and are always searching the bottom for food. They are live food specialists, and do best on a diet of live blackworms and occasional feedings of brine shrimp, glassworms, bloodworms and other tiny invertebrates. Some individuals will take fish flakes and other non-living foods, but they rarely do well without live food (Xenopus, on the other hand, will eat nearly anything, living or otherwise!). They do not compete well with most tropical fish, but should be fine with cave fish.

    Please let me know if you need any further information.
    Good luck and best regards, Frank Indiviglio.

  1. Pingback: otopark bariyeri

About Frank Indiviglio

Read other posts by

Being born with a deep interest in animals might seem unfortunate for a native Bronxite , but my family encouraged my interest and the menagerie that sprung from it. Jobs with pet stores and importers had me caring for a fantastic assortment of reptiles and amphibians. After a detour as a lawyer, I was hired as a Bronx Zoo animal keeper and was soon caring for gharials, goliath frogs, king cobras and everything in-between. Research has taken me in pursuit of anacondas, Orinoco crocodiles and other animals in locales ranging from Venezuela’s llanos to Tortuguero’s beaches. Now, after 20+ years with the Bronx Zoo, I am a consultant for several zoos and museums. I have spent time in Japan, and often exchange ideas with zoologists there. I have written books on salamanders, geckos and other “herps”, discussed reptile-keeping on television and presented papers at conferences. A Master’s Degree in biology has led to teaching opportunities. My work puts me in contact with thousands of hobbyists keeping an array of pets. Without fail, I have learned much from them and hope, dear readers, that you will be generous in sharing your thoughts on this blog and web site. For a complete biography of my experience click here.