We have previously gone over the problem of Discus eating their eggs while spawning, or shortly thereafter. We will now go over fertility. Next we will go over what happens once the eggs hatch, but before the fry are free swimming.

Fertility is an issue with Discus and will vary drastically between different pairs. Some pairs will be totally infertile; other pairs will be infertile at first and then will become fertile. On pairs that are fertile, the percentage of fertile eggs will range from just a few to, best case scenario, about 80% fertility.

There are three main causes of infertility in Discus. The first one is mechanical and is caused by the male not doing his job and fertilizing the eggs. The second and third are biological and are due to either the eggs or sperm being genetically or chemically infertile.

When Discus lay eggs, the male should follow the female on a fertilizing run as soon as she does an egg laying run. Some males only make the run after every two or three egg laying runs. It is my experience that these males tend to have a lower fertility rate. Some males will not fertilize at all. These tend to be the males that also are most aggressive on eating the eggs. There is very little you can do to change these males.

Some Discus are infertile due to water chemistry. To optimize fertility, water temps should be kept constant between 84 and 88 degrees. Ph should be kept constant at 6.5. Heavy filtration, if possible, is a big plus. I try and avoid doing water changes at this time.

Discus that are genetically infertile will never be fertile. Please note that keeping water temperatures above 96 degrees for over a week will usually result in the permanent infertility of Discus. Some Breeders have been known to purposefully sterilize the discus they sell to keep others from being able to breed the strains they have developed. We would never do this.

We will now go over what to expect after the eggs have been laid. This is where the frustration starts. The first two issues that you will be confronted with are eating of the eggs, especially by the male, and infertility. We will go over the eating of the eggs first. We will go over fertility in the next part of the series.

The number one problem, and the one you must get past, with breeding discus is the eating of the eggs by the parents. While both parents will eat the eggs, the male does it more often. This is often done as they spawn and there is very little you can do if this occurs while spawning. The female will make her egg-laying run and then the male, instead of following her with a fertilizing run, will follow her and eat the row of eggs. This behavior is most common in new pairs. A majority of new discus pairs will eat their eggs. Fortunately, they will often stop this behavior as they become a more mature spawning pair. If you get lucky and they do not eat their eggs when spawning, there is a good chance that they will eat them before they hatch. Fortunately, if you get this far, there is something you can do. You can, at this point, take the eggs out and artificially raise them or you can take a mesh screen (house soffit screen works very well) and fit it directly over the eggs. This will allow the discus to still blow on the eggs and bond with them, but will keep them from eating the eggs. Obviously, you will need to have planned for the spawning and will need to have created the screen prior to the actual spawn. If the eggs do not get eaten and are fertile, they should hatch out in three days and become free swimming in about six days.

The spawning process is the pinnacle of Discus keeping. This has always been my favorite part of Discus keeping and I still, 30 years after my first spawn, find it fascinating.

The first sign that your discus are getting ready to spawn will be their obsession with cleaning a rock, or filter tube or side of the aquarium. Once you see both of them doing this, spawning will usually follow within a day or two. You will also see them start doing the mating dance. They will swim towards each other at a slightly upward angle. Once they get next to each other, they will shimmer and then swim away from each other at a slightly lowered angle. The most spectacular aspect of the spawning will be the colors of your Discus. Whatever their color, it will become MUCH more intense and vibrant during spawning. This will be the prettiest you will ever see your Discus. They will also become aggressive toward other fish, including Discus, at this time. They will aggressively defend the breeding site from all intruders, including you.

At some point after your Discus start doing all of the above, they will actually lay the eggs. It will start with the female rubbing her belly, and her breeding tube, against the surface that they have cleaned. She will always lay in an upwards motion. The total length of the spawning run will be between ½ and three inches. She will lay between 1 and 12 eggs per spawning run. The male Discus will usually then follow directly behind her in the same basic motion spraying the eggs. You usually cannot see the actual cloud. The entire process can take between one and five hours.

This is when the fun is over and the frustration can start. The first two issues that you will be confronted with are eating of the eggs, especially by the male, and infertility.

Unpacking Your Shipment

Your new fish should be kept in a separate, isolation tank for at least 2 weeks.

If you do not have a separate isolation tank, any other large container that is free of chemicals may be used. Make sure that you put a heater and aeration in the temporary tank. Remember, this is only temporary. The temporary isolation tank should be a bare bottom tank with nothing in it other than the aeration and a heater (no plants, snails, fake plants, gravel,
driftwood, decorations or other fish).  After two weeks, When the fish are showing no signs of stress or disease, they can be moved to their permanent aquarium.

CHANGE 40% OF THE WATER DAILY FOR THE FIRSTWEEK AND THEN EVERY OTHER DAY FOR THE SECOND WEEK.

It is urgent that you unpack your fish as soon as possible. Float the bag in the isolation aquarium where they are going to stay. DO NOT open the bag at this time! You may find that you need to remove some of the aquarium water to prevent it from overflowing when the bags are placed in the aquarium. If necessary, remove some aquarium water into a clean plastic bucket or other food safe receptacle. Be sure the container for excess water does not have any reside from household cleaners or other potentially toxic chemicals, as you will use this water to refill the aquarium later.

Allow the bags to float for at least 45 minutes to allow temperatures to slowly equalize (longer if necessary). Open the fish bags only when you are ready to immediately put them into your aquarium. DO NOT put any water from your aquariums into the bags or vice-versa! Avoid netting as much as possible.  Gently pour off most of the water from the bag thru a net. Then release the fish from the bag directly into the aquarium. Another good method uses a smooth plastic spaghetti strainer with small holes. Gently scoop or release the fish into the receptacle, drain the water and place the fish immediately into the aquarium. Large specimens can often be simply hand placed into the aquarium. If these methods are not applicable, place a large net over the top of a clean bucket with enough water to cover approximately a third of the bottom of the net. Open the bag and carefully pour some of the fish into the net and immediately place them directly into the aquarium. Try to avoid a net full of fish as they will ball up in the net, and the ones underneath can be damaged from compression and friction. Remember that water from the bag may react with the water from the aquarium, and could be very harmful. Never mix bag and aquarium water!

Sometimes during shipping, fish lie at the bottom of the bag and appear dead. “Playing opossum” is a common animal stress behavior. Carbon dioxide also acts to tranquilize the fish. Even if the fish look like they are mostly dead, put them into an aquarium as outlined above. Watch their mouths and gills for 5 minutes.  If there is no movement of the mouth or gills for a full 5 minutes, it is dead.  Leave the aquarium lights off to further reduce stress, and leave them alone. You will be amazed how clean water and stress reduction help!

Like other animals, fish produce carbon dioxide as they breathe. When carbon dioxide is dissolved in water, an acid is formed, lowering the pH of the water just like in a carbonated beverage. Fish also produce ammonia, which can be very damaging. Ammonia is present in water as NH3 or as NH4+, or as a combination of these forms. The toxic form of ammonia is NH3. The proportion of NH3 versus NH4+ is dependent on pH. The lower the pH, the lower the amount of NH3, and the greater the proportion of the less damaging NH4+. In the wild, freshwater fish naturally experience wide changes in pH.

One of the reasons fish are able to be shipped long distances in closed bags is because the pH in the shipping water drops, making the ammonia non-toxic. The carbon dioxide acts as a tranquilizer. The moment the bag is opened, and exposed to the outside air, carbon dioxide escapes, the pH of the water immediately begins to rise, and ammonia becomes deadly. Fish tissue damage will then occur very quickly. NEVER add water from a shipping bag into your aquarium, as you do not want all that harmful ammonia in your aquarium. NEVER add water from your aquarium into the shipping bag. Acclimate the temperature by floating the bag in the aquarium water, and then immediately open the bag and release the fish into the aquarium, minimizing the introduction of the bag water.

DISCUS****VERY IMPORTANT*** ***PLEASE BE PATIENT**** YOUR DISCUS WILL NOT SHOW THEIR FULL COLORATION FOR SEVERAL DAYS !! THEY WILL START TO GET THEIR COLORATION IN A FEW DAYS AND SHOULD HAVE THE FULL COLORATION FOR THEIR AGE WITHIN ONE MONTH. MOST DISCUS DO NOT SHOW THEIR FULL AND FINAL COLORATION OR PATTERN  AS JUVENILES AND WILL NOT UNTIL THEY ARE MATURE ADULTS (AROUND 5″). DISCUS  WILL OFTEN LAY ON THEIR SIDES FOR A FEW HOURS, OR EVEN SOMETIMES A COUPLE OF DAYS, AFTER THE STRESS OF SHIPPING. CHECK THEIR GILLS FOR AT LEAST 5 MINUTES TO MAKE SURE THEY ARE NOT BREATHING BEFORE GIVING UP ON THEM! DO NOT FEED YOUR DISCUS FOR 24 HOURS AFTER YOU RECEIVE THEM. DO NOT PUT ANY BRIGHT LIGHTS ON THEM FOR THE FIRST DAY.

FLOWERHORN***VERY IMPORTANT***FLOWERHORN ARE AGGRESSIVE, SO MAKE SURE THAT THEY ARE PUT INTO A STERILE ISOLATION TANK FOR TWO WEEKS WITH PLENTY OF HIDING PLACES.  LARGE PCV TUBES CUT TO ABOUT 6 INCHES MAKE GREAT HIDING PLACES.  PLASTIC BAGS CUT INTO STRIPS MAKE GREAT DISTRACTIONS.  PLEASE REMEMBER THAT MOST JUVENILE FLOWERHORN ARE GREY WITH NO HUMP (KOK) AND MOST OF THE STRAINS LOOK PRETTY MUCH THE SAME AS JUVENILES.  MALES WILL START TO GROW THE KOK AT AROUND 4 INCHES.  THEY WILL START TO PUT ON THEIR COLORATION AND PATTERN AT AROUND 4 INCHES, BUT WILL NOT HAVE THEIR FINAL COLORATION UNTIL MATURE.  IT IS OK TO FEED FLOWERHORN 2 HOURS AFTER DELIVERY.  FLOWERHORN SHOULD NOT BE KEPT WITH DISCUS OR ANGELFISH.

Introduction: Columnaris (Flexibacter columnare) is a very common type of bacterial infection in Discus. It responds somewhat differently than other Bacterial Infections and is not limited to the skin, but affects the gills and sometimes it also infects the internal organs causing liver failure and sepsis. It is always associated with fish that are stressed. The most common causes of stress are shipping, overcrowding, low oxygen, handling injuries, poor water conditions (improper Ph, Hard Water and water that is to cold). Almost all fish have the disease in a dormant state. It will occur in fish that have their immune system weakened due to stress or that are exposed to high levels of the bacteria from other infected fish. As it is dormant and can become inflamed when stressed, it is EXTREMELY important to quarantine newly shipped fish in a sterile tank after the stress of shipping. If a healthy, but newly stressed fish from shipping is exposed to other fish in an established tank that does not have pristine water conditions, the whole tank can quickly become infected. Likewise, a healthy fish that it is exposed to an infected tank, even if it is largely dormant in some of the other fish, will quickly become infected.

Pathology: Columnaris usually starts as a bacterial infection of the skin. Within 12 hours, it will often move to infect the gills and within 24-48 hours it can infect the inner organs. Columnaris can become lethal as quickly as 18 hours and untreated it will be lethal in 50-90 percent of the fish within a week. The most common cause of death is infection of the gills, making it impossible for the infected fish to diffuse enough oxygen through the gill membranes. It is somewhat like the fish getting Pneumonia and suffocating. These severely infected fish will usually die within 24 to 72 hours. Some fish that are able to ward of the infection of the gills will still die from internal organ infections. The two most common types of inner organ infections is liver failure leading to the fish dying from a buildup of toxins and sepsis, which is a total infection of all of the inner organs that will often lead to heart failure.

Symptoms: Columnaris in the early stages is very difficult to differentiate from other Bacterial Skin Infections. Like Bacterial Skin Infections, Columnaris usually first shows up as a dulling of the coloration in the Discus and in some strains will lead to the fish getting dark. Infected fish will huddle in the corners of the tank and will clamp their fins. The respiration rate of the fish will increase significantly. As the infection develops, unlike most bacterial skin infections, some fish will develop white patchy sores and will have frayed fins with white fuzzy edges. The fish will usually lose most of their appetite. In the final stages, the fish will become emaciated and will often lie on their side at the bottom of the tank.

Treatment: Columnaris is a gram negative bacterium. It should initially be treated with a gram negative antibiotic. We have found that the most effective antibiotic is the old standard Tetracycline (which is actually effective against both gram positive and gram negative bacterium) We actually use OxyTetracycline which is more water soluble than Tetracycline. If caught early, most fish will still have some appetite left and the most effective way to administer the antibiotic is with treated food. We sell the medicated food, please go to this link: https://www.somethingsphishy.com/flake-fish-food-with-oxytetracycline-p-1360.html   By far and away the most effective treatment of Columnaris is with Potassium Permanganate. You must be EXTREMELY CAREFUL with the dosage of the Potassium Permanganate. In even slightly higher dosages than those we list below, Potassium Permanganate is lethal within an hour. We actually use it to sterilize tanks when they are empty before we add fish. If you research the treatment of fish with Potassium Permanganate, you will likely get very confused. Most treatments state the dosage in parts per million and other terms that the average hobbyists will have difficulty translating into a useable treatment dosage. We have described it below in terms that most aquarist will have no trouble in using. We recommend starting with a premix of 30 grams per 1.5 liters of water. You can use a food scale, that can be bought at any grocery store, to weigh it out. You can purchase the Potassium Permanganate powder at the Florida Tropical Fish Farmers Coop website.
http://ftffacoop.com/index.php?main_page=product_info&cPath=57&products_id=498

Once you have created the premix solution, you should treat the tank initially with 7 ml of the premix per 10 gallons of water. You can buy a syringe that uses milliliters at any pharmacy. You will see that the tank turns purple to brown, depending on how much biological material is free floating in the tank. The coloration will slowly turn clear (tan in severely infected tanks). After 24 hours, do a 50% water change and add the water back in treated at 3 ml of Premix per 10 gallons. Repeat this every day for seven days. If you ever mistakenly over dose the tank, you can neutralize it immediately using Hydrogen Peroxide.

Prevention: All Discus tanks should have UV filtration/sterilization. We sell great UV filters on the website. Please go to this link https://www.somethingsphishy.com/aquarium-filters-c-41_77.html       UV Filtration is the most important first line of defense. As Columnaris is brought on by stress, any causes of stress should be eliminated or reduced. The most common stressors are overcrowding with fish and/or plants and poor water conditions. Once again, we cannot overemphasize the importance of quarantining newly shipped fish in a separate, sterile isolation tank for at least two weeks. This should be a bare bottom tank with no other fish (other than the ones received), plants, snails, gravel, driftwood or ornaments. It should only have a filter, heater and aeration, all of which have been sterilized.