Discus breeding for fun

Discus Breeding for Fun

A Starting Point

This article is aimed at those who already have some experience in keeping discus and who would like to move on to breeding them, and therefore we will not cover the basics of discus keeping. There are articles on this site for those who are just starting out with discus, and others on diseases and their treatment.

Breeding discus is not difficult, if you can keep them you can breed them. Raising the fry is a bit more work and can take a fair amount of space, but it is do-able even with a full time job.

Throughout this guide please bear in mind that this is based on my experience of breeding discus over several years, and that it is not the only way to do it. There are as many opinions on this subject as there are discus breeders and none are necessarily wrong or right, better or worse than any other method, it is simply what people have found to work for them.

Setup

Breeding in the community tank is unlikely to result in any fry reaching maturity, yes it can and does happen, but it is very hit and miss and you are only setting yourself up for disappointment if you try. You are better setting up a dedicated breeding tank and associated grow out tanks, after all you want to make it as simple as possible to minimise the work involved and to maximise the numbers of potential fry.

Tanks

Breeding tanks can be any shape and size as long as they have sufficient volume of water; I work on about 18-20 gal. per pair and 1 pair to a tank. For me 450mm/18” cubes are perfect, but 24x15x12 or any other small tank will be fine. Too large a tank can lead to the fry getting separated from the parents in the early days, and the lost fry almost always die.

Grow out tanks, ideally you need two or more, but you can get away with one to begin with. You could remove the parents back to the main tank and use the breeding tank as a first grow out tank, but I prefer to move the fry. 24” tanks are ideal as a first tank as it keeps the fry together, 36” tanks are OK too and are better for larger juveniles.

All the above tanks are bare bottom, i.e. no substrate, ornaments or plants of any kind. You need to keep these tanks as clean as reasonably possible, this means wiping down all internal surfaces and siphoning off all debris on a daily basis. In my experience failure to maintain these tanks as well as possible is a common cause of real problems when breeding discus, some of which will not become apparent for several weeks.

For me an 18” breeding cube and 2x 36x15x12 grow out tanks worked well, letting me raise up to about 30-40 fish to 3” before moving them to a bigger tank or selling them on

Filters

Power filters and external canister filters are unnecessary and unhelpful in a breeding setup. The flow is too great and it can lead to fertilisation problems, fry being trapped against the inlets and being blown away from the parents, as well as removing small food particles that are better left in the tank for the fry.

Good quality air driven sponge filters are perfect, and much cheaper too. I usually use double the manufacturers recommended sizes, so for a 100l tank I would use a 200l filter. Additionally they trap food on the surface keeping it available to the growing fry and can harbour lots of micro-organisms for the fry to feed off, a win-win situation. In the spawning tank adjust the air flow to give moderate but not excessive aeration of the tank, for the grow out tanks you can turn it up a bit.

It goes without saying that your filters need to be mature, I keep mine in a sump off the main system when not in use, but you can keep them in your main tank too.

Heaters of sufficient capacity for the tanks.

Water

Water is always a contentious issue in discus circles, but as a general rule if the fish are happy in your “normal” discus keeping water then they will breed in the same water. For most domestic strains you can safely discount the myths about fertility problems and the need for super soft water for breeding. If you use RO water anyway then you know what to do, a little softer will never hurt, but is not essential by any means.

Pairs

Be very careful if you are looking to buy a pair, terms such as “mated pair”, “matched pair”, “breeding pair”, “true pair” mean absolutely nothing. If you have a supplier you trust then buying a pair is less risky, otherwise only buy a “pair” if you can see them with fry. Eggs are not good enough, they could be: 2 females, just hanging out together, or infertile, only once you have fry can you be sure they are male & female and that they are fertile.

Much better is if you can raise a pair in your main tank and move them to a breeding setup once they have had a bit of practice. As a first pair I would recommend you avoid snakeskin and spotted varieties as well as wild fish as they can be more difficult. Ideal strains to start with are pigeon blood and turquoise varieties, as they tend to be easy to care for and rear.

Preparation

So we have out tanks set up & we have our pair, where do we go from here? Well the first thing is to let the pair settle into their new home, while they do so feed them up. Good quality frozen foods supplemented with live foods such as white worm, earthworms etc. is ideal, fed 2-3 times a day. I tend to feed dry foods to my pairs 2-3 times a week with the bulk of their food being frozen. You already know this from keeping discus, just feed a little more than “normal”.

Because of the heavier feeding they will need more water changes than normal, I try and do 25-50% a day on the breeding tanks. This will often trigger spawning all by itself, if it does not I will do a 50% change using cold water & they nearly always spawn within 48h. If this fails try smaller water changes for a week then a large one, experiment & see what happens, there are no “rules” here, find out what works for you. It helps if you keep a few notes to keep track of what you are doing.

I have made no mention of plastic pipes, breeding cones, plant pots, slates leant up against the glass or an of the other paraphernalia that seems to be so de rigueur these days. There is a simple reason for this:- you don’t need them, and neither do the fish, so why make things complicated? If you feel like it feel free to use them, it is up to you.

Hopefully our pair are getting into the mood, & if you see them starting to lay leave them alone, turn down the filter if you can without disturbing them but don’t make an issue of it. Once they have finished don’t forget to turn the filter back up.

Now we have eggs.

At this stage I will stop, or do minimal, water changes and tank cleaning so I don’t disturb the parents or fry. Over the next 3 days they will tend the eggs, and then the wrigglers (hatched eggs) for another 3-4 days before the fry become free swimming and attach to the parents sides. During this time the parents may not feed, don’t worry about it, just offer a small amount of food & remove it if not eaten after an hour. Once the fry are on the parents I reduce the water level in the tank to about 7” just enough for the parents to stay upright easily. This allows the fry to find the parents easily and the parents to round up any lost fry. At this stage the parents will probably start feeding again, but because of the reduced water volume only feed sparingly. Carefully siphon off any debris daily and top up the tank to the same level.

After the fry are free swimming for about 3–4 days (about 10 days after the eggs were laid) I start feeding with newly hatched brine shrimp 3-6 times a day, start with small amounts squirted over the parents backs, you will soon see the fry darting out to eat them. You can supplement this with fine fry foods such as those produced by ZM.

Now the work begins, with the increased feeding you need more water changes, and with the rapidly growing fry you need a constant source of brine shrimp. For the next 3-4 days I will fill the tank then reduce the water level, this reduces the risk of fry getting too close to the siphon tube or the parents getting upset as mine don’t seem to like very shallow water with fry. You should also start wiping down the inside of the tank again, it will need it.

The fry will be about 10mm long by now and you can refill the tank as they are more than big enough to cope. Keep feeding brine shrimp and water change 50% daily, I start slightly overfeeding at this time as the fry are always on the lookout for food and brine shrimp can survive several hours in the tank. After about another week you will see

them trying out the parents food so add a little more for the fry, but keep adding brine shrimp, once they get to about 1” they will stop eating it, then it is time to stop.

In a commercial setting, the fry are separated from the parents after about 2 weeks free swimming. As I am not looking for maximum production from the parents, and because it is easier on the fry I tend to leave it for about 4 weeks. By that time the fry are about 1” and eating normal foods, and will need treating for flukes or the “4 week syndrome”.

Some things to bear in mind.

Egg eating is not a problem, most pairs do it several times before rearing a batch of fry. Once they start raising fry they don’t often go back to egg eating.

Some parents wont eat, or wont eat properly, from the time they lay until the fry are separated. Don’t worry about it just feed them up again afterwards.

The parents can become very “battered” & ragged, especially if it is a large batch of fry, they will recover although it is occasionally necessary to remove one parent to prevent serious damage.

The fry feed all day, so in an ideal world you will be able to feed them during the day.

Growing on

At about 4 weeks the juvenile fish are 1” long and actually look like tiny discus and it is time to separate them from the parents. I usually net them all into a bucket containing tank water and formalin at a dose of 1-2 drops per litre for 40 minutes, then sort out any deformed or badly stunted fish and cull them. The remaining juveniles are transferred to a new tank.

Now you have separated them it is time to feed up the parents, especially if they have not been feeding. I like to get them “back into a normal routine” of water changes & feeding immediately.

At this size I like to keep the juveniles crowded as they seem to do better in a big shoal, and heavily fed on

everything they will eat, principally beefheart based food, but any high protein diet is OK, 3-6 times a day. Daily

wipe down and water changes are essential to maintain as near perfect water conditions as you are able, 50-90% a day if you are able, this gets the fish off to the best possible start.

At weekly intervals the juveniles are assessed and separated based on size, the only consideration being that there is always at least 10 fish per tank. I try to work on having 2 groups; small & big, this seems to prevent the smaller fish loosing out. In groups smaller than 10 I find that the fish don’t do as well at this size.

At 8 weeks old the largest will be pushing 2” and the smaller should be 1.5” or so, anything less than this is unlikely to grow properly. Again look for any deformities or defects and cull as required, you should have weeded out all the poor stock at this stage. The only reason to keep culls at this stage is if you would be left with 10 or less fish, in that case keep them until the juveniles are 3” or so.

If you are lucky you will now have a new batch of fry ready to be separated from the parents…oh the joy.

Some sell fish this small, personally I like to keep them until 3” which will be at about 12-13 weeks. At 3” they can be moved into a larger tank or added to the general community tank as they are usually large enough to cope.

Some thoughts on culling

I know many find this an uncomfortable topic, but if you are planning on breeding discus or any other animal it is important that you understand why we need to do so. As breeders we have a responsibility to maintain or improve the bloodline of the animals in our care, it is no different breeding dogs, horses, cats, sheep etc. we need to ensure the species in question is not reduced or degraded by our efforts.

Domestic strains of discus have some very strange genetic inheritance, some worse than others, but all seem to throw up some poor fry in every generation. This ranges from poor shape, always a subjective consideration, to gross deformities like bent spines, missing fins & gill plates etc. On a practical front these fish have nothing to offer, there are enough poor quality discus out there without those of us who do this for fun to add to the

problem, so we cannot pass them on in good faith, and we cannot hope to keep them all ourselves as they take just as much resources as a good, healthy fish.

Done correctly it causes no distress to the fish, using clove oil or MS222, both are anaesthetics, the fish just go to sleep. There is an article in the library covering this in more depth.

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