Our Fascination with Discus -- (continued)
Even now, so many years later, I have trouble swallowing when I remember the tragedy our ignorance brought on. We decided to have no more discus until we knew a lot more about keeping and breeding a wide variety of tropical fish.
Several years and many thousands of baby fish later, we thought it might be safe to try again. We proceeded to buy young discus by way of a commercial wholesaler. I have no quarrel with wholesalers. They do a difficult job and, generally, serve our hobby well but we had no success with the discus they provided. Some of them lasted almost a month before they succumbed to hole-in-the-head or some other less identifiable disease. Several hundred wasted dollars later, we were about ready to give up for the second time.
When some young brown discus were held up for bids at a WNYAS, (Western New York Aquarium Soc.), auction I almost passed on them. My hand seemed to go up of its own volition. The auctioneer asked, "How many bags?" I heard myself say, "All three." We were now the owners of three medium sized tank-raised discus. As it turned out they weren't in the best of shape. Once they were unbagged the cloudy eyes became evident. I thought I knew why the bidding hadn't gone very high.
We put them in a high twenty gallon tank and gave them only routine maintenance, food and care, expecting nothing. A few months later I noticed that two of them had relegated the third one to a corner of the tank. I moved it to another tank and gave them a slate. It wasn't long before they used it for their first spawning attempt. As I recall, they didn't get it right the first few time but eventually they produced several nice batches of babies that fed off their parents' sides and grew rapidly. They made us proud.
We kept and raised eleven youngsters from the first successful spawn. They had their own 50 gallon tank and eventually we sold them as proven mated pairs. (That means they had produced viable eggs.) Five pairs! Over the years we've had both kinds of luck but the good kind with discus was just beginning.
Brown is beautiful but when some young brilliant turquoise discus came up at a Hamilton auction we were ready for a change. We paid a lot more than last time, but went home with four beautiful juveniles. This time they were in perfect condition. They were given a high twenty gallon tank and, it took about a year before anything significant happened. They caught us by surprise because they were still fairly small but they knew what to do. We had two pairs. We housed them in separate twenty gallon tanks next to each other. After a few false starts one pair achieved success and produced quite a number of successful spawns. They never seemed to produce as much body slime as the browns but it was adequate and the fry survived. The second pair had one or two small successes but tended to eat the eggs pretty consistently. That's what lead to our experiments with artificial hatching and rearing but more about that later.
Our successes with discus began in the early 80's so I'm sure you will understand if I don't try to document all the pairs and the second generations that blessed our fish room with fry.
I don't want to create the impression that there were no problems. We never had the huge spawns of 200 plus babies that 'real' discus breeders talk about. Ours ranged between 35 and 100 with a lot less than that left after culling. We found that most of our breeders produced well for about a year or so and then tailed off and eventually quit completely. After swearing off rainwater and wholesale stock we found health problems fairly manageable provided we worked our butts off maintaining excellent water quality. Discus seem to be more susceptible to external and internal parasites than many other fish and don't respond well to even a little neglect. They do respond well to frequent, regular water changes. (If possible, soft acid water above 80 degrees F.) How to produce that became less of a problem when we acquired a Reverse Osmosis Filter.
When this RO was attached to our water line it pre-filtered the water through a 5 micron cartridge, then a carbon cartridge and finally a membrane which theoretically will only allow pure water molecules to pass. The result is a small but steady supply of very soft water and a larger amount of harder waste water. (That waste water doesn't need to be wasted. It is excellent for African cichlids, Anableps and other hard water loving fishes. Your garden will do very well on what's left over if you can figure a way to get it out there.)
We have always collected the RO water in a large plastic barrel in which a submersible heater keeps the temperature about 84 degrees F. An old canister filter is used to cycle the water through a bag of peat moss to help produce the desired acidity. This isn't very high-tech, I know, because I've seen some of the sophisticated setups that dedicated discus breeders use, but it has served our modest needs and was all we could afford.
As to the peat moss, we like the crumbly Canadian stuff. We mix it with RO water and boil it in a big enamelled pot for about 20 minutes. If the pot is covered securely and stored in a cool place the peat will keep for awhile. We find that we have to use it to refill the bag in the canister filter every couple of weeks or it loses its effectiveness. (By the way, the water in which the peat has been boiled can be used in moderate amounts to stimulate some tetras to spawn.)
We are in the habit of adding a small amount of pH buffer to the water before adding it to the discus tanks aiming at about 6.5 pH. We also add a little regular tap water to help with the buffering. (Pure RO water has very little buffering ability and can sometimes plunge to a very low acidity level.) Bear in mind that all this is helpful in getting adult discus pairs to breed but not absolutely necessary. It hasn't been necessary for baby and juvenile discus. Once they were eating brine shrimp nauplii on their own and had been removed from the parent's tank, we found that they grew fine in regular water as long as it was frequently changed and their tanks were kept clean and uncrowded.
We feed our discus a variety of high quality flake, frozen and live foods. I stress the quality. Frozen brine shrimp is one of their favourites as long as you can get the good red stuff that doesn't look like it was dead for awhile before it was frozen. By far the cheapest, most nutritious frozen food we have used is a homemade recipe that contains a mixture of fish, beef heart, beef liver, baby clams, eggs, greens and lots of other good stuff. It is thoroughly processed with gelatine powder as a binder and frozen in flattened plastic bags. One of the things we learned is that a discus that doesn't want to eat is either sick or is going to be sick.
Among live foods they really like is tubifex worms. They make an excellent food if you can grow your own and, (we were able to do this for a time), know that they are safe. Commercially available live tubifex is sometimes contaminated with parasites which can be very bad news. Most of our discus enjoyed the live brine shrimp that we grow in plastic ponds in our back yard but one pair performed weird contortions every time we put some in their tank. Apparently they were convinced that these creatures were really baby discus that just didn't know how to behave. I never saw them eat a single shrimp.
I was never very good at telling the sex of discus. Dumb luck took care of the problem most of the time but I did pick up a couple of clues over the years. Female discus are often, but not always, a little smaller than males of the same age and, when they are ready to spawn, the female's breeding tube, (ovipositor), is large and stumpy. The male has a more slender, pointed tube and, of course, it isn't an ovipositor.
The red turquoise pair shown on the front of this newsletter were perhaps the most unusual discus we have ever acquired. We spotted a tank of these in one of the former pet stores in St. Catharines. They had been purchased by the shop from the wife of a hobbyist who had unfortunately died. The store owner had divided them into large, medium and small discus. They were in beautiful condition and we bought one of the larger ones. At home the next day I scratched my head and finally came up with an idea. (Remember that females are quite often a little smaller than males.) We went back and purchased a medium, (ten dollars cheaper). This pair was carefully quarantined for about 6 weeks. For the last 2 weeks a small, culled discus from one of our rearing tanks was placed with them to see if it might come down with something to which they had resistance. Nothing happened so they were moved to a high twenty gallon tank complete with spawning sites. The day after the move they spawned. Furthermore they raised that spawn and every spawn thereafter. Although they didn't lay large numbers of eggs, they continued to spawn about once a month for the next year and they remain the only discus we've ever known that never ate their eggs or their babies. Their 'Best Parents' award was well earned.
Unlike this charming couple, some discus pairs never learn to keep their eggs and/or babies. If you really must have some of their offspring sometimes the only answer lies in artificial hatching and rearing. We tried it a few times early on and found that the hatching part was easy. Almost the same technique used for angels would get us a nice batch of free-swimming discus babies all looking for something to eat. In my opinion no one should even try spawning discus until they have some success with angels, but I'll briefly review the procedure we use. We first arrange to have the parents spawn on a removable object, (sometimes by making almost all other surfaces unavailable). A small, clean tank is prepared with a mixture of water from the breeders' tank and some fresh RO at a temperature just slightly warmer than the spawning water. A submersible heater is installed and adjusted. An airstone is dropped in and adjusted so that a stream of bubbles will keep the water circulating gently. A lid is obtained and the bottle of methylene blue drops is placed nearby. After the parents have finished spawning and fertilizing and before they start eating, the spawn is removed and placed in the hatching tank. Methylene blue drops are added to the water until you can barely see the eggs. (Usually about 10 drops per gallon.)
About the third day when the good eggs have hatched and there are wrigglers on the slate we exchange the airstone for a charcoal-loaded box filter covered with bridal veil to keep the babies from getting sucked in. This effectively removes the blue from the water and allows us to see what's happening.
By the seventh day we have removed the slate with, usually, most of the dead and fungused eggs still stuck to it. Now the discus babies start swimming around looking for something to eat. If they were angels we would just put some newly hatched brine shrimp nauplii in the tank and watch their bellies turn pink. We tried that with discus and half a dozen actually survived but most of them simply starved to death. They expect to find their first food stuck to their parents' sides. As yet they don't seem able to chase and capture their dinners.
We gave up on artificial rearing until after I retired. By then I had read and heard a great deal about success with egg formulas and feeding in bowls so I decided to try again. Instead of egg I decided to use a product sometimes called microfood and to make a paste of it by mixing it with dissolved gelatine powder.
The result is something that looks and feels like thickened egg yolk but doesn't spoil as quickly when stored in the fridge. Pat contributed a large porcelain mixing bowl.
I smeared this concoction on the inside of the bowl and also on a piece of amber coloured plexiglass that I hoped to use as a parent substitute.
I drilled a hole in it and attached some fish line so it could be suspended in the bowl and moved up and down to bring more of the food within reach of the fish. I made up a bucket of half RO and half regular water at the temperature of the hatching tank and put some of this in the bottom of the feeding bowl. I then proceeded to syphon the babies from their hatching tank into the bowl with a small syphon made of a length of rigid plastic tubing to which a suitable piece of airline had been attached. The water level in the bowl was adjusted and the plexiglass 'parent' lowered so that food was within reach of the babies. I covered the bowl as much as possible to slow the rate at which the water would cool off. Since our fish room is pretty warm, this didn't prove to be much of a problem. While the babies ate for the next 20 minutes or so, I took the opportunity to change about half the water in the hatching tank and clean out any fungused eggs or other debris. From time to time I lowered the 'parent' and raised the water level in the bowl to bring fresh food within reach of the babies.
To finish the routine I used the remaining prepared water to top up the hatching/rearing tank, removed most of the water from the bowl and then used my syphon to transfer the, (not quite so hungry), babies back into their tank.
Now that doesn't sound so bad, does it. The catch is that I had to do that routine approximately
every four hours for two days. There were some losses but most seemed to be thriving. On the second day I started crushing a little newly hatched brine shrimp nauplii into the smeared mixture as well as letting some live nauplii swim about in the bowl. I was watching for pink.
The literature says that if you haven't got them eating shrimp on the third day, you wipe it out and try again with another hatch. By the middle of the third day I had approximately 85 babies with pink bellies and I felt really, really good. From there on it was a piece of cake. I just had to feed them small amounts of newly hatched shrimp regularly, syphon out what they didn't eat and change water frequently. I gradually shifted them to complete regular water. They grew rapidly so I soon moved them to a fifteen gallon rearing tank and started expanding their diets.
I think you might like to try this or some variation of it once or twice but my wish for you is that you get a pair of discus that don't think it's proper to have their kids for lunch.
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