Raising Discus Fry Artificiallyby Vern Archer N.A.D.S. last published Dec 1994 in "Our Discus"
There has been much controversy surrounding the topic of "artificial raising discus fry". In this article I am going to give my opinions and methods of raising these fry artificially. A great number of breeders use the artificial method and there are many methods that have varying success.
First of all, there are no easy ways of breeding and raising good quality discus, artificial or naturally. The fry require constant attention and dedication for maximum growth and development. A good prerequisite is to have raised other types of fish. A great number of people get into the breeding of these magnificent fish solely for the money with absolutely no experience in the fish hobby. Their lack of knowledge, dedication and poor feeding habits has given the discus hobby a bad reputation.
Before we get into methods of raising young, we should ask ourselves, why would anyone want to raise discus artificially when raising on the backs is so much easier? What are the disadvantages and advantages of artificial raising? These are frequently asked questions and I will attempt to answer. Personally speaking I raise the majority of my discus naturally on the backs, so that places me at both ends of the argument. The answer to my first question, why? Well, after trying to get a pair of fish to raise naturally, trying softer water, lowering pH, varying the temperature, live foods, and trying various enhances such as peat, the parents continue to eat the eggs or fry (if you use a wire mesh around eggs). At that point I either sell the fish (not as a pair) or I try the artificial method. So, in other words, I try the artificial method only as a last resort.
What are the disadvantages and advantages? Advantages are that the eggs can be removed on a continuous basis approximately every 10 days (normal spawning cycle) giving you greater production. You can (if you are good at it) raise more fry per batch. There is less of a chance of parasites being transferred to young. Disadvantage, well first of all, it is a lot more work (feeding every 4 hours like a newborn baby). It is said that artificially raised young will be less likely to raise on the backs down the road in future generations. I personally feel there is merit to this argument although I have had success with artificially raised parents raising their young naturally. How about size? It is my experience that the growth potential is the same using either method providing care and dedication are maintained.
Okay, enough about the pros and cons this is how I do it.
First, after the spawn, I usually wait an hour or so to make sure the eggs were fertilized. I then remove the eggs and place them in a 2.5 gallon tank with an air-stone and either methylene blue (makes the water dark like ink) or I use Maroxy by Mardel laboratories (with limited light). Now, how do I keep it warm? Well I have a six foot kitchen counter built with a clear plastic hood or incubator type tent over top. There is plenty of room under the tent for the bowls and the 2.5 gal tank containing the eggs. The tent (incubator) is heated by a small 500 watt electric heater with an oscillating fan maintaining 88 degrees F. Note the air temperature must be maintained around 88 degrees F in order to keep the water at 86 degrees F. This is due to the cooling effect of the air-stone and surface water evaporation. Keep all containers covered to minimize this cooling effect.
On the second day (24 hours later) perform a 50% water change on the eggs. This will lighten the colour of the methylene blue in the water but do not add more. If you are using the maroxy after the water change add back the full dose as per instructions on the container (1/2 teaspoon per 10 gallons). I use new conditioned water for all my water changes. I use a 45 gallon plastic drum with a submersible heater and air-stone with regular tap water (325 microsemens) alter the pH to 6.0 and a temperature of 86 degrees F. This keeps my water chemistry constant with only a slight variation between incubator and 45 gallon drum. Temperature differences can be further minimized by keeping a covered 1 or 2 gallon pale of this water inside the incubator.
On the third day (48 hours later), perform another 50% water change on the eggs this will lighten the colour of the methylene blue even further do not add any additional methylene blue or, if you are using maroxy, no additional maroxy is required after the water change. At this point you should start to see the eggs developing into fry.
On the fourth day (72 hours later) you will see the fry wriggling on the side of the spawning cone. At this point I move the wriggling fry to the bowl. I use white 2 gallon bowls (ceramic or porcelain). I have tried various types and colours and find the white gives me the most success. Smaller bowls will work depending on the size of the spawn but again I prefer the 2 gallon size. The fry are moved using a modified turkey baster (the opening is enlarged care must be given not to have any rough edges when performing this modification) along with 50% of the original water from the 2.5 gallon tank and 50% new water into their new home the 2 gallon bowl. Again, I emphasize the importance of temperature and water chemistry and keeping the bowls covered. I use 1/4 inch clear plexiglass for covers but glass works as well.
On the fifth day (96 hours later) I clean up the bottom with my turkey baster and again do a 50% water change. Note, I use no air-stones or air during this initial process, I find the babies can be attracted to the air and are killed and it really isn't required when using the larger bowls and frequent water changes.
On the sixth day (120 hours later) I again clean the bottom of the bowl and complete another 50% water change. At this point the babies will start swimming and are a little more active. Note feeding does not begin until the babies are at the surface schooling looking for food.
On the seventh day the babies are hungry looking for food. If you insert a spoon or dark object into the bowl they will be attracted to it, at this point feeding will begin. Now, I want to talk about the amount of light used, the egg formula and the preparation of the bowls.
Light using a retractable reading lamp (40 watt bulb), try varying the amount of light by moving it. You will notice the fry responding to this light and this can be used to entice the fry to feeding. Note, not enough light and the fry become disoriented and not school properly for feeding. Too much light and the fry will sink to the bottom again not feeding. Experiment with the light and note the fry's reaction to it.
As for the secret formula, I use egg-yolk powder (not egg powder try a bakery for a source) and Davis or Knox Gelatine to bind it to the edge of the bowl. The gelatine I mix according to the package instructions using half again more gelatine. Make sure that all the kitchen utensils and mixing bowls are free from dish washing detergent. When melting the gelatine into the boiling water and mixing, the solution should be clear. If its cloudy, start over - there is detergent residue or something making it cloudy. Let the solution cool slightly (warm to the touch) before adding this mixture to the egg-yolk powder and mix until you have the consistency of peanut butter without any lumps. Now spread this formula (keep it a very thin layer not to thick) around the upper inside edge of you bowls at the water line. I usually make up 6 bowls at a time and store them in a fridge until needed. The refrigerator allows the gelatine to set on the bowl.
Now we have the bowls in the fridge cooling and the fry look hungry, so it’s time for their first feeding. I remove the bowl from the fridge and warm it in the sink using hot water being careful not to get the hot water on the egg mixture on the inside of the bowl. When I feel it’s warm enough I place the bowl inside the incubator and fill it with 50% new water and 50% from the bowl containing the fry (fill to just under the egg at this point). I then add the fry using a small net (gasoline funnel screen, never used of course) and/or turkey baster to the feeding bowl. I now raise the water level of the bowl exposing the egg to the fry. I note the time because we do not want to over feed, usually around 20 minutes. (Utilizing a magnifying glass, you should see their bellies swollen with the yellow from the egg) I save some of the water from the original fry bowl containing the fry in a small pale. I then clean the bowl using hot water. Next, I add back the saved water and top up with new water. Again, keep the bowls covered and incubator closed while feeding. After 20 minutes you remove the babies back to their original bowl that you have just freshened up for them. I use the plastic funnel screen to move the fry back, the object of the game is to move the fry without contaminating their bowl with water from the egg bowl. Fun right; actually it gets easier as you get good at it. Now at this point you can put a sliver of an antibiotic into the water to help keep the bacteria count down (dose would be as per anti biotic package I.e. maracyn 2/10's of cap).
Now that you have completed your first feeding you will repeat this every 4 hours for two possibly three days (like a new born baby right). The duration is very important as I have found, especially during the first 24 hours, 4 hour duration between feeding must be adhered too, going longer will weaken the fry and ultimately jeopardize your work to this point. If you time the feeding's right you can get away with up to 6 hours through the night if you lower the lighting. I hope the timing is on a weekend or you can make it home at lunch.
On the third day (day 9) of egg bowl feeding, introduce as well, newly hatched brine shrimp (20 to 24 hours old) saturate the bowl with the brine and using a turkey baster keep the brine shrimp moving so they don't settle on the bottom of the bowl. Soon you will start to see little orange bellies. As they get full remove them to their fresh bowl.
On day four, (day 10) by the end of the day, all babies that are going to survive will be on brine and you will not longer need to use the egg. Those that remain are usually belly sliders and will not make it so they can be removed and destroyed.
Now, hopefully you have a 2 gallon bowl containing orange bellied discus fry. One note about the brine shrimp take extra care to rinse the brine shrimp well to remove the salt. Always use newly hatched brine shrimp, I have a morning and evening batch to accomplish this.
Continue feeding 5 feeding's a day, do not overfeed and remove dead uneaten brine shrimp as it will contaminate the water quality. Keep moving fry when full to a clean fresh bowl containing original with new water. At this point you can introduce a small air-stone but continue with some residual light on for the fry at night.
I keep the babies in a bowl for another five days, then I move them to a 10 gallon tank with a small sawed off sponge filter and keep the tank at about 50 to 60 % full until the fry get used to feeding then gradually increase the water level. It is extremely important to keep the bottom of the tank clean free of uneaten brine shrimp. It is a good idea to have two tanks and move the babies every couple of days so that the fry's environment remains clean.
After another couple of days or so I start to introduce frozen daphnia with the brine and after another 5 days, a very fine beef-heart mix is also introduced. They will grow quickly and they should be ready in another week or two to move up to a larger tank 20 or 25 gallon.
After another 2 weeks they will be eating beef-heart nutritional mix 4 to 5 times per day and can again be moved to a larger tank 35 to 50 gallon. Be careful not to crowd. I usually split the discus by size at this point this allows the smaller discus to catch up in size.
After a total of 8 weeks they should be 1 1/2 inches nose to tail if you have done it right. Good Luck!
