Where There’s a Whiptail, There’s a Way: Spawning Rineloricaria eigenmanni

by JT Thomas

Image © JT Thomas 2009

I saw my first whiptail cat in a fairly crappy pet store about a year or a year and a half ago. Sitting immobile on the bottom of the tank it looked to me like some sort of Cardassian spacecraft. They’re not pretty, these fish, but there are not many fish that have a more interesting look to them, and they are not the usual aquarium fare. And this is good, for they turn out to be fairly easy to breed.

Whiptail Catfish are widespread throughout South America, with approximately 30 species (according to Wikipedia) in a wide variety of habitats. I was able to procure a breeding trio of Rineloricaria eigenmanni from a local breeder. These are a very common species in the Columbian and Venezuelan llanos, and are usually found in clear whitewaters. Such areas are characterized by rounded rocks, a sand bottom, driftwood, and leaf litter. In streams there would be a fair current, and so this is what I kept in mind in setting up the tank. In order to facilitate spawning, I was advised to put a number of 6 to 8" lengths of 1 1/2" diameter PVC tubing open at both ends (bamboo works too, I have read.)

Rineloricaria are peaceful and adaptable. Temperature range is 75 to 84, pretty typical of tropical species, and they thrive in pH 6.0 to 7.4, also pretty typical. They are non-territorial and, "will not harm even the smallest fry ¹." And they are omnivores, eating both vegetation and meaty food items that fall to the bottom of the tank.

Now, on the chance that one cannot obtain proven breeders, they turn out to be quite easy to sex. The head of the male is more rounded than that of the female, and mature males in breeding condition have a beard of fine bristles on the side of the head (odontodes). There is an excellent picture of a male and female side by side on PlanetCatfish.com, in the CatELog entry for R. eigenmanni. (Pictures 13 & 14), that clearly shows the difference in head shape and the odontodes on the male.

The Tanks

I set up my breeding trio in a 20 long. Over an inch thick substrate of fine sand, I placed smallish rounded stones, boiled oak leaves, and some local driftwood (also boiled). The driftwood was held down with a slab of granite until waterlogged, then the granite was set upright to direct the current from the filter.

Filtration is an Emperor 400, turning over the tank volume 20 times hourly. In retrospect, I cannot recommend this technique in a shallow tank with a sand bottom. In the future, I would use air driven box or sponge filters and powerheads to agitate the surface and keep the water moving.

Initially lighting was provided by a single bulb 30" strip light, though now the tank shares a dual bulb 48" shoplight with a pair of 10 gallon tanks. A 75 watt heater was set to keep the tank at 78°F. I used my typical water, which is fairly hard Fairfax county ordinary, with a pH crash brought on by liberal use of AmQuel+ and NovAqua+ in pond concentrations. This brings general hardness down into the single digits (leaving a bit of carbonate) and brings the PH down to just south of Neutral (about 6.8). Of course, the Oak leaves depressed this further.

For breeding real estate I put in two 6 to 8" lengths of 1 1/2" PVC pipe.

Into this, I introduced my three whiptails, a shoal of 6 Corydoras metae, and a shoal of 6 Gold tetras (4 of which were certainly Hemigrammus rodwayi, and 2 of which may have been something else.) Somewhere along the line, breeding populations of pond and ramshorn snails made it into the tank as well. And here’s what it looked like:

Image © JT Thomas 2009

Not a particularly attractive tank, but a pretty fair biotope.

Since this was in my living room, I tinkered with it several times to improve the look of it.

Image © JT Thomas 2009

I used fishing line to wrap one tube in Java Moss and the other with a bit of java moss and several small java ferns.

Over time, as the Oak leaves decomposed, I started adding Java Moss to replace them, and it currently carpets about a third of the tank. (I will be collecting oak leaves to cover another third the next time I have the chance.) Apparently, the C. metae like to spawn in leaf litter. Also, I have so arranged the granite and the tubes so as to direct a goodly amount of the filter output right down the breeding tubes.

Image © JT Thomas 2009

After the first spawn, I removed the gold tetras. Also, I have been removing any Corydoras fry about every 2 months.

Conditioning the Breeders

I treat my fish pretty well when I have time, so every evening, into the tank would go 2 or 3 spirulina tables and a couple of different types of food: a rotation of 3 days dry, 2 days frozen, 1 day live, and 1 day nothing in each week. Dry foods included 3 kinds of flake, 3 kinds of pellets, freeze dried bloodworms or tubifex, and (once I detected cory fry) cyclopeze powder. Frozen is Bloodworms, Spirulina brine, Daphnia, freshwater frenzy, or mysis shrimp, typically half of a cube. Live food is blackworms and brine.

Over the month prior to breeding, I did a 30% water change weekly, using treated, aged water.

The First Spawn

A cursory glance at the initially set of the tank will let the wise discern that getting a view down the breeding tubes was less than totally convenient. Therefore, when I discovered the male sitting on a clutch of eggs on Christmas morning ’08, I could not be sure how long they had been there. There were perhaps 60 eggs, perhaps more, all of a jade green color, quite large as eggs go for fish I have spawned, in excess of 3mm in diameter. I can no longer find the basis for my belief that it would take 11 to 14 days for them to hatch, breeding summaries of whiptails being thin on the ground, but I had found this information somewhere, and planned on moving the tube, male, eggs, and all to a 10 gallon tank on 5th or 6th of January (so at 11 or 12 days). This is where it is important to know when the spawn actually happened. As when I put the 10 gallon down preparatory to siphoning off water from the 20 to fill it, I noticed 3 tiny whiptails, 5 or 6 mm long, duplicates of the parents in all but size, collected near the waterline. Unfortunately, those three and perhaps a half dozen others were all I was ever able to find of that first hatch. The tube on the morning of the sixth was clean of all eggs, and the male had retreated to a hiding place in the leaves, having, presumably, jumped the gun and eaten the balance of the eggs, or abandoned them to be eaten by his cohabitants.

Given that the females had already taken on the appearance that they had swallowed half a cocktail olive, I assumed I would not have long to wait to take another shot at getting this right...

The Second Spawn

Image © JT Thomas 2009

...And nor was I mistaken. When I checked the tube in front of the filter on Sunday the 11th of January, preparatory to doing a water change, there was the male, doing what were essentially push-ups with his pectoral fins over another clutch, about the same size as the first one. Expecting a 10 to 12 days of waiting until the hatch, the very next weekend, January 18th, I set up a 10 gallon tank to hatch the eggs in (and to give the male a chance to bulk up a bit before going back into the main tank – he doesn’t eat while he’s guarding eggs, and a lusty pair of fecund females can drive him to starvation. He’s like a college boy that way.) This was filtered with an air driven hydrosponge 1, filled with water from the 20 gallon, bare bottomed, and heated with a 50 watt hang on heater. Using a half gallon specimen container, I moved the tube, male, eggs, and all, into the 10 gallon, then tossed in a goodly wad of java moss for infusoria production (infested with snails as it was) for between meal snacking for the impending fry. I also put in the three fry that had survived from the first spawn, as well as a half dozen Corydoras metae fry. I began by feeding the janitorial staff a small portion of cyclopeze each morning and a fragment of a spirulina tablet and a bit of frozen baby brine/frozen rotifer mix each evening.

The eggs hatched on the 19th and 20th, and I soon had 5 dozen or so baby whiptails hanging like so many miniature, superattenuated bats near the waterline by the sponge filter.

ProTip: The babies need a high oxygen content in the water. Aerate the tank well.

I upped the feeding amount slightly, except for putting in a whole algae tablet nightly for the male’s gustatory restoration. I returned him and the spawning tube to the main tank on the first of February, not quite 2 weeks later.

Image © JT Thomas 2009

Raising the Fry

Everything you are likely to read about raising whiptails will tell you that the hard part is not getting them to spawn, but raising the fry. With a twice daily regimen of cyclopeze powder and microworms, or a 2:1 mix of frozen baby brine and frozen rotifers, coupled to a daily spirulina tablet, I was able to keep my losses down to 1 or 2 weekly. After about 2 weeks in the 10 gallon tank, I set up a 25 gallon tank thus: Bare bottomed, a stick of native driftwood from another tank and two small hunks of granite as aufwuchs growth encouragement. To this I added enough java moss to just about half cover the bottom of the tank (all of the moss from the 10 plus about half as much from other tanks) and enough Brazilian pennywort to 3/4 cover the surface. I added a second sponge filter and switched out to a 75 watt submersible heater. I also removed the cories at that time.

At about 3 weeks I removed the rotifers from the mix, and at about 5 weeks I added daphnia and upped the ration of spirulina tablets to 2. At about 6 weeks, I moved the tank into the new fishroom stand and added my 4 female guppies and a cloud of their fry to it. From there on, I fed flake or small frozen food twice daily, and 2 to 3 spirulina tablets or a half sheet of plain sushi-nori each night. By about 6 weeks, the loss rate had dropped to 1 weekly. I never lost one that was longer than an inch and a half.

Water changes were done directly from the spawning tank. I’d squeeze the filters twice, remove all the plants and décor to a bucket with tank water (so as to not lose any fry hiding in them), and then siphon as much detritus off the bare bottom as feasible, before removing about 8 gallons (in total) of the water. I’d then replace the water in the main tank with conditioned and aged water at room temperature so as to drop the tank temperature into the low 70s to stimulate the cories to breed.

Ultimately, I was able to bring about 3 dozen baby whiptails, ranging from 2 to nearly 3 inches long to auction in late April.

Image © JT Thomas 2009


Spawning Whiptail cats is really not all that difficult. Given a male and one or more females, the proper housing for the male to guard the eggs, a sand bottom, and plenty of varied foods, they will spawn. Raising the fry is a bit challenging, but with good hygiene and water changes and plenty of small, protein rich food paired with a good source of vegetation, there’s no reason to be alarmed by the occasional death: most will survive.

Image © JT Thomas 2009

¹ Per planetcatfish.com, CatELog entry for R. eigenmanni

October, 2009

Where There's a Whiptail, There's a Way.
Copyright 2008 - 2009 JT Thomas

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