Category: Catfishes

Care, spawning, selection, species and genus information.

The Whiptail Catfish: an Interesting Fish

Some fish are definitely beautiful. Other fish are decidedly ugly. Some fish are neither; instead they are definitely interesting looking. As much as beauty is the eye of the beholder, I think the many varieties of whiptail catfish fall in the “interesting looking” category.

These are flattened, very slim, armored catfish from South America. The top caudal fin ray grows into a long whip-like filament that gives them their common name. Overall they have a pre-historic appearance to them, looking a little like an crocodile. They belong to the family Loricariidae. In fact one of their genera, Loricaria, gives the family its name. A revision of the Loricaria genus in 1978, placed most of the aquarium species in the genus Rineloricaria.

There are many species under a handful of genera that are offered under the name whiptail catfish. I’m not sure of any of the species I’ve kept for many Rineloricaria look alike, with the possible exception of R. lanceolata which is very distinctive looking, with a mostly clear dorsal fin and a broad black stripe near its leading edge. Large whiptails are probably species of Sturisoma, Loricarichthys or Pseudohemiodon. A related genus is Farlowella, the twig catfish.

I became acquainted with whiptails on my first year of aquarium keeping. A friend of mine gave me a fish, which had been caught in a creek that runs behind my old high school. I immediately looked the fish up in my only fish book but I didn’t like what I read: “This is an extremely sensitive fish in an aquarium and if its ideal conditions are not met, its won’t live for long”. The rest of the information was fine. Scientific name of Loricaria parva, from south Brazil, harmless to other fish, only bred once by Carrol Friswold (no date given).

Either I had a tough fish, or I provided ideal conditions for the fish lived for quite a while. I lost it, along with many other fish, when I filled my pond with water that was straight from the tap (the city had increased the chlorine in the water). One thing I observed right from the beginning was that the fish was strictly nocturnal. It spent the whole day buried in sand, with only the eyes protruding. At night, I would switch off the room lights and leave a small reading light illuminating the tank. The fish would then shake off the sand and swim around the tank looking for food.

My second experience with whiptails came when I set up my large tank. Once I decided that the substrate was going to be sand, I remembered my first whiptail so I decided to keep them again. I bought a “pair” of whiptails. The person at the store made a point of picking a light-colored one and a dark-colored one because according to him that’s how you sex these fish. I didn’t believe it for a minute as I had read a few books by then and knew that the best way to sex them is to look at the fish from above. The females are wider at a point behind the pectoral fins, while the males are wider at a point inline with their eyes. Males also develop odontodes, bristles that cover the face and pectoral fins. Whether the person at the store really knew his stuff, or it was sheer luck I ended up with a pair. The male developed wonderful bristles all over his face and pectoral fins. The ones on the fins looked like Velcro hooks, so he became the only fish in the tank to have a name: Velcro.

Unlike my first whiptail, neither of them bury themselves in the sand. For many months Velcro had a favorite spot on a piece of driftwood. He would lay there motionless for most of the day. The female always lies close to an Amazon sword plant, usually radially aligned with the plant so she looks just like a dead leaf. As the plants grew in size and number, the whiptails became part of my invisible fish population (close to 20 fish that I hardly ever see). The only time I see them is when I do a water change. I always end up trying to suck one of them with the siphon hose thinking it is a dead leaf. At other times I find the long whip-like ray on the tail fin near some plants and I can follow it back to the owner, usually Velcro. His whip has reached close to three-quarters of his body length. Being in a mostly undisturbed large tank ensures that the whip doesn’t break.

I’m not sure what their favorite food is, though I like to make sure the catfish get their share of food. I feed sinking shrimp pellets, Spirulina wafers, frozen blood worms, and frozen brine shrimp, usually less than two hours before the lights go out. The sinking pellets and wafers last for quite a while, and I always ensure I overfeed a little with the frozen food to make sure the night crew finds something to eat when the lights go out. There is usually some algae on the front pane of the tank, though I have never seen any of the whiptails attached to the glass, nor have I seen them scraping the driftwood. My references indicate they eat algae, flakes, and pellets. At any rate, I’ve had them for five years now so they must be happy.

I don’t know if my pair ever bred, or even tried to. They are usually in the same corner of the tank, though never side by side. Their strictly nocturnal habits, their shyness, and the lush plant growth in the tank make them very difficult to observe. Though males are good fathers, I doubt that the young would survive the other sucker mouth catfish and the tetras. Besides Carrol Friswold, many people have bred whiptails in the aquarium, and I believe Birgit can provide the details.


Klee, Albert J. Enjoy Your Catfish, Harrison, New Jersey: The Pet Library Ltd.

Pereira, Raul. Como Cuidar do seu Aquário, Rio de Janeiro, Brazil: Edições de Ouro.

Riehl, Rüdiger, and Baensch, Hans A. (1986). Aquarium Atlas. Melle, Germany: MERGUS-Verlag.

Sands, David (1988). A Fishkeeper’s Guide to South American Catfish. Morris Plains, New Jersey: Salamander Books Ltd. (Tetra Press)?

Book Review: Corydoras: The most popular armoured catfishes of South America

This is a review of the new CAS library book Corydoras: The most popular armoured catfishes of South America, by Werner Seuβ (1993). This book was purchased for the CAS library with financing from a special auction of Corydoras catfishes donated by CAS members Birgit McKinnon and Gernot Kostera.

Dr. Seuβ (pronounced soos: don’t laugh) is an avid aquarist, and he has raised almost the entire Corydoras species flock in his own home in Sparneck, Germany. Since the publication of this book he has also had a fish named after him; Corydoras seussi. Too bad that this fish was described too late to be included.

This is a fabulous book.

All 128 Corydoras species known in 1993 are in the book; and all of them are presented with description, a location map, and a pen-and-ink drawing; and almost all of them with a color photograph as well.

And the photography is the best I have ever seen in any publication other than National Geographic. Each picture shows the fish clearly and with exquisite sharpness in a beautifully planted tank. Not a blemish or any hint of grain is found is any of the photographs. Yet each photo has soft natural light that does not reveal any clue as to what lighting was used. It is however obvious that the subjects were at least partially fore-lit as the reflective iridescence of the scales is clearly seen. No better photographs of aquarium fish will ever be published (the photograph of the two Corydoras “C5” is particularly wonderful). Unfortunately, the book make no mention of what camera, film, or lights were used; only that the photographs were “from a collection of many thousands of slides”.

The book also has pen-and-ink drawings of each fish by Jürgen Härtl. These are also of the very highest quality.

As far as the other technical aspects of the book’s production goes, it is your typically German over-engineered artifact that uses the highest quality paper and bindings.

The book was translated from German by Klaus Berold and Bernard Michaelis, who did an outstanding job. The grammar of the translation is impeccable. Their only lapse is the retention of the single German word “Fundorte” in the map foldout. And of course the proper German spelling of “Seuβ” is retained, rather than the commonly seen translation “Seuss”.

The book uses metric units throughout, except that the German degrees of hardness are used (these can be converted to PPM by multiplication by 17.9). The spelling convention used in the translation is British, which has the annoying affect that temperatures are written with the redundant ” º ” symbol, as in “27 º C”, rather than the scientific standard “27C”. Another minor annoyance is that Corydoras, although always capitalized, is not italicized when it is used outside of a complete scientific name (and unfortunately one or two scientific names didn’t get italicized either).

The final comment about the book’s production is that this is neither a readily available nor inexpensive book. Despite extensive searches, I have yet to find a Canadian supplier. It can however be ordered over the Internet from the States. Try the Aquatic Bookshop ( who have it in stock for US$67.44. Or else try Amazon ( who can get the book for US$49.10, but only on special order (4 to 6 week before shipping). You can pretty much double those prices once you pay for shipping, currency exchange, and GST.

The book opens with a brief presentation of the classification of the Corydoras, as members of the subfamily Corydoradinae, of the family Callicthyidae, of the order Siluriformes.

The Corydoras share their subfamily with the genera Aspidoras and Brochis. It is stated that Brochis can be told from Corydoras by the larger number of dorsal rays in Brochis: 10 to 17 rather than the 6 to 8 in Corydoras. Aspidoras is however more difficult to identify; as they have the same number of dorsal rays as Corydoras, but tend to be smaller and more elongated than the typical Corydoras. Aspidoras do however have a dual fontanel (defined as an “opening in the headbone”) while Corydoras and Brochis have a single fontanel. This is of no use in identifying living specimens however.

I think it is a shame that the book is restricted to detailed descriptions of only the Corydoras species, and leaves out Aspidoras and Brochis. The entire subfamily Corydoradinae could have been covered with relatively little additional effort, given that Brochis and Aspidoras have so few species. Why not include the two related genera in a future edition?

The housing of Corydoras in the community aquarium is discussed in the second chapter. It is recommended that at least 6 to 8 of each species be kept together in a tank. The practice of keeping Corydoras in pairs or in mixed-species schools is discouraged. A substrate of well-rounded gravel is suggested. The tank should be planted and supplied with caves. The recommended water chemistry is not very restrictive: a pH of 6.5 to 7.5 and a hardness up to 270 PPM CaCO3 is recommended (by these criteria Calgary’s water is too alkaline by 0.5 points but has an OK hardness). Temperatures in the range of 22C to 28C are advised. The need to feed the Corydoras properly is also stressed: do not rely on them scavenging the other fishes’ leftovers; feed them sinking food tablets, thawed frozen foods, or live foods.

Seuβ cautions against the use of several common aquarium medications, as these are detrimental to catfish. He also states that "Even though I have used many types of medications I have barely been able to save diseased Corydoras“: an experience repeated by aquarists all over the world who have wasted their money on over-the-counter fish medicines. It is always better to maintain fish properly, thus preventing diseases from occurring in the first place, than trying to cure a diseased animal.

The breeding of Corydoras is discussed next. While some Corydoras spawn readily in the aquarium, others have proven difficult. Seuβ has bred more than 30 Corydoras species, but there are still some that continue to frustrate.

Seuβ uses 45-liter breeding tanks with a thin (2 to 3 mm) layer of fine gravel on the bottom, some plants (usually Anubias), a few hiding places, and a fairly powerful outside power filter. He also keeps a Sturisoma species catfish in the breeding tank for algae cleaning duties (apparently they won’t eat the Corydoras eggs).

His breeding hints include instructions on how to catch a catfish in a display aquarium: don’t feed for two days then put a couple of food tablets in a net propped up inside the aquarium. Be patient and the catfish will (eventually) find their way inside the net.

Once the catfish are caught, they must be sexed: male Corydoras have much more pointed anal fins than females.

The prospective parents are transferred to the breeding tank, where they are fed heavily on live foods. White worms, Grindal worms, and Tubifex worms are choice foods (the thinness of the sand layer is to prevent the worms from burying themselves out of the catfish’s reach). Mosquito larvae are also recommended as food.

To stimulate breeding, Seuβ recommends a change of water every two days with fresh water that is slightly cooler than the tank, and a drop in temperature of 4C at night. Lower the pH with peat filtration, and provide a stronger current. Changing the fish’s diet and/or the location of the tank to a brighter location may also help. Oddly, he also recommends placing “dried seed-free alder cones” in the tank, but does not mention their intended purpose (pH reduction?).

Courtship is initiated by the male, who swims around in a nervous fashion agitating the female. Pairing begins when the female stops avoiding the male and remains stationary at the bottom of the tank, making only small movements. The male will position himself cross-wise in front of the female in the “T-position”. The female then releases eggs into her ventral fins, which she cups into a basket to carry them. The eggs are fertilized by the male while in the basket. The female then carries the eggs to be deposited at a suitable site, usually a plant leaf. Seuβ recommends Anubias plants as suitable eggs sites, as they are tough enough to withstand the abuse.

The plant with the eggs is then transferred to a 20-liter bare-bottomed hatching tank, to which the anti-fungus medication CILEX is added. The hatching tank is kept aerated and filtered with a sponge filter. Temperature s kept at a relatively low 23C or 24C, as it is stated that the lower temperature results in lower mortality. The tank bottom is to be kept clean with a brush.

Unfertilized and fungused eggs are removed as they are noticed. Two or three days post hatching feeding is begun: newly hatched brine shrimp are fed to all except the fry of the smallest Corydoras species, which require infusoria.

The fry are transferred to rearing tanks when they outgrow their hatching tank. A thin sand substrate is recommended since Seuβ finds that bare-bottomed tanks, unless kept scrupulously clean, result in fungus attacking the ventral fins and barbels. A powerful filter is also advised. And finally, it is suggested that the young fry be sorted for size every couple of weeks, or the smaller fish will never attain their full size.

The chapter of breeding advice is followed by a table of 28 representative species, and for each lists the desired sex ratio, temperature, size of eggs, hatching time, time of first feeding, suitable first food, total number of eggs laid, and the number of eggs carried by the female at any given trip in her ventral fin basket. The last entry I found most surprising, since most Corydoras females only carry 1 or 2 eggs at a time, but a few species really load up, with as much as 25 eggs in the case of Corydoras elegans.

The remainder of the book contains detailed descriptions of 128 scientifically described species of Corydoras, with three of these species having separate entries for their identified subspecies. There is additional entries for 17 undescribed species identified by their “C numbers”, 1 through 17. Each description includes a detailed line drawing, a textual description of the appearance with pointers on how to distinguish the fish from similar species, and a location map of the place the fish is found in nature. Most descriptions also have a color photograph.

All Corydoras aficionados need this book. It is simply the best book on any genus of aquarium fishes available, and it would be the constant companion for anyone wishing to begin breeding a representative collection of these fishes. My only serious concern is that, with a publication date of 1993, the book is already getting old. Many new species of Corydoras have been properly described since the publication of this book, and a second edition would be greatly welcome.


Seuβ, W. 1993. Corydoras: The most popular armoured catfishes of South America, Dähne Verlag, Ettinglen, ISBN 3-921684-18-8 ?

A Spawning of the Pot Bellied Pig, er, I mean… Aspidoras maculosus

I first heard of these fish when I was asked by a very fishy friend if I wanted some. So after getting filled in on these busy little catfish and of course diving into my books for more information, I placed a call and said sure! About a month later they were shipped to me. It took a month because I also wanted some other fish that were too small to ship at the time, so we waited for them to all be shipped together.

When I opened the box, I saw cute little catfish that resembled some of the smaller Corydoras species. They were quite pale from being in the box all day. By the next morning their colors were more normal, with the entire fish being a dark gray with black splotches and of course the cutest little whiskers. The whiskers are slightly longer than that of the small Corydoras. These fish have little black beady eyes. They are kind of creepy that way.

The ten fish were put into a 125-liter aquarium, alone at first. The water parameters were temperature 24C, hardness 280 to 290 ppm, and a pH of 8. These fish were raised in hard water but not quite as hard as it is here. A couple of weeks later I added five rosy barbs and five golden barbs out of my 250-liter aquarium. I do water changes weekly, unless I have over-fed, then I do them more frequently.

I noticed that the Aspidoras looked like they were climbing the walls, or rather, sort of walking up the walls. It looked rather strange! I had never seen corys do this. They do the same thing when they are in a net. They walk up the net. These fish also like a water flow. They will jump like salmon up the waterfall of the 300 Aquaclear to get into this filter to lay their eggs. I have also found eggs across from the water flow were it goes across the tank and hits the front wall.

My first few attempts at raising some fry were eggs collected from the above mentioned places. I moved them into a 10-liter tank that contained three Corydoras habrosis. The water parameters were the same as the 125-liter tank. Out of approximately 15 eggs, I would raise one, two, or as many as four fry. I don’t know what the problem was but I did blame it on the hard water. After all it couldn’t have been anything that I did. HA HA.

My next attempt was to move a rather large spawn (over 60 eggs) to the 80-liter aquarium. This looked promising! I had a large hatch rate…I was so pleased! Then after about 4 days, I noticed what I thought were yolk sacs (that should have disappeared) were instead getting bigger. What could possibly cause bubble bellies? I had never seen this before. I blamed it on the hard water. In actual fact, I believe that it was caused from a bacterial build up in the water. Its much easier to blame the hard water than it is to say my aquaria aren’t clean enough. I wonder about this though as I bleach the aquaria between spawns and rinse them out at least three times, and dry it out with a fish towel. Then I let them air for a few days, before I add water and fish. Needless to say, I didn’t raise any fry from this most promising spawn.

My next attempt was to put a pair in a 40-liter aquarium. I saw nothing after several days, so I moved them back to the 125-liter tank. I didn’t clean the aquarium out this time, but instead added a pair of checker barbs. After a few days I removed them. I couldn’t tell if there were eggs or not so I left it for a couple of days, to see if anything would appear. When I lifted out the plastic plants and black undergravel filter I saw nothing. I was just about ready to clean this tank out when I noticed what looked like a baby cory swimming around. So I know for a fact that the Aspidoras did spawn, but I missed it completely. I moved the only fry to the 10-liter aquarium.

OK, OK, in the mean time I was doing some research, and talking to other hobbyist, and was told to try some different things. So the next batch of eggs, I used straight tap water with no chlorout. I filled a clear plastic container and put in the eggs that I took out of the 300 Aquaclear. A couple of the eggs got a small white spot (the beginning of fungus) so I removed them. The rest all hatched. I moved them to a bare 10-liter aquarium. There were eggs that were one day later that I followed the same procedure with. Twenty-five were raised from the two spawns until they were just about one month old in the 10-liter and then they were moved to a 40-liter tank until they were a selling size.

These fish will eat you out of house and home if you let them. My little pot bellied pigs started out with micro worms, then graduated to sinking wafers and Grindal worms. Then white worms, flake pellets, algae wafers, and all kinds of flakes.

All in all, once you get past their beady little eyes, they make a nice aquarium pet. They are a rather fast and busy little catfish that I would not recommend mixing with slow docile fish. BEWARE – They can eat and eat and eat and eat …?