Pendidikan,Pertanian seiring...

Rabu, 5 September 2007


by Ricky Grange
First published in the Vancouver Aquatic Hobbyist Club Newsletter.

When I first started keeping discus, breeding them was a mystery to me. Those who were successful in doing so must have been privy to some "secret knowledge". Over the past four years of playing with these "magical" fish the secrets have unravelled themselves for me. Breeding discus has actually proven not to be the ultimate challenge but actually a rather simple undertaking... after all, what can be easier than a fish that not only guards its young but also feeds them! My purpose in writing this article is to share with you the techniques that I use. By no means do I claim that this is the best or only way of doing things - it’s just what works for me with the conditions I have to work with.

Discus with fry

There are two ways to go about obtaining a breeding pair of discus. The most common is to buy a group of young discus and grow them up together. For a good chance of getting a pair, at least six discus must be purchased, hopefully from a few different sources so as to get some genetic diversity in the breeding program. These fish are then housed together until pairs can be determined. When two discus pair off they will defend a territory in the aquarium against all of their other tank mates. When this behaviour is observed it is time for the breeder to move the "newlyweds" to an aquarium of their own. The second way to obtain a breeding pair is to go out and buy one. This is a more expensive route, since proven pairs sell for several hundred dollars, but it will yield the fastest results.
Regardless of how you get your pair, you will need an aquarium set up for them with the objective of breeding in mind. A twenty or twenty-seven gallon tall tank is ideal for these "tall" fish. The bottom is left bare, so that removing any left over food and other debris is easy. The only decor required by the pair is a spawning surface. Discus lay their eggs in the same manner as angels, and so a vertical surface should be provided for them to deposit their eggs on. I use an inverted ceramic flower pot, but the discus aren’t picky and will use whatever surface is available. A potted plant or two can be added to the breeding tank if so desired, and will provide some shelter for the pair, but this is not essential. As far as filtration goes, a sponge filter should be used to handle the biological load, and an outside power filter to pick up any debris that may be in the water. I also like to add a mesh bag of peat moss in the power filter so as to better replicate the natural water conditions that discus come from.
This brings us to the first and most important secret you will need to know if you are going to have any success breeding discus. This is the secret of water quality. Discus come from the warm, soft, acidic waters of the Amazon River. It’s no surprise then that discus thrive when these conditions are replicated in the home aquarium. For both general maintenance and breeding of discus the pH should be kept at 6.5, and the temperature around 86 F. Any alterations that need to be made to the water chemistry should always be done prior to the water being added to the tank. For general maintenance water changes should be performed weekly. However in the breeding tank, a small water change should be done every day, or every second day. Frequent water changes increase appetite and promote mating activity in discus. It’s no coincidence that discus will often spawn after a water change.
The second secret is related to the first, and this is the secret of food. If good water quality is maintained the discus will have large appetites and should greedily accept any food offered to them. My discus get fed only frozen bloodworms. The reason for this is that they are clean and convenient to use. Other foods that can be used include beef heart, Tetra Color Bits, frozen or live brine shrimp, and live white worms. If feeding beef heart, one must be careful that none is left over because it will foul the water very quickly. Live tubifex or black worms should never be fed to discus at any time, as I can guarantee that they will introduce parasites to the tank.
Once these two secrets are mastered, breeding discus is a cinch. The breeding pair will lay eggs as often as every week, as many as fifteen times. They will usually go through two of these spawning cycles in a year. The eggs take 48 hours to hatch , and are free-swimming another 72 hours later. Immediately upon becoming free-swimming the fry will move to their parents’ sides, and start feeding off the mucous secretion that is produced by the parents during this time. The fry will feed off their parents’ sides for as long as you leave them together, but they should be offered newly hatched brine shrimp after being free-swimming for five days.
I recommend that the fry be removed between two and three weeks after reaching the free-swimming stage, as leaving them with the parents any longer can be hazardous for the parents’ health. The youngsters will actually reach a point where they can start ripping off scales and bits of flesh from the parents. Once the fry are removed the pair will spawn again in short order. The fry, now in a tank of their own, should be fed six or more times a day. The best foods to give the fry are newly hatched brine shrimp and chopped bloodworms. It’s amazing how fast baby discus grow, for the first few weeks there is noticeable daily growth. In the fry tank it is important to do a partial water change every night after the last feeding.

From now on it’s just a matter of remembering the two secrets of success for keeping and breeding discus; water and food!

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