Why do my friend's breeding pairs of Discus eat their eggs everytime?

Question

My friend has been trying to breed Discus for long time now, but to no avail. All his pairs, eat their eggs immediately. He has tried covering the tank to make them feel safe and sometimes kept them side by side with other pairs to bring out their protective instinct. He feeds them beef heart, blood worms, worms, larve etc. I must mention that he doesn't have the tools for monitoring the water chemistry. He does use a heater and a thermometer. Another thing I must say, is that since he doesn't get much water supply and he is busy with work, he doesn't do much water changes. I notice, the water is dirty most of the time. Now, that I have given the entire senario, please explain as to why they are doing this to their young and whats the solution.

Answer 1

To be totally honest, there is no ready answer. Some Discus or any other fish for that matter, just do that no matter what you try. If he has had several pair do it, there may be something in his water quality, such as high nitrates, but anything including that is really just a guess. I would also suggest that in some cases all or some of the eggs may be infertile and that could cause such a reaction. I had similar problems breeding severums until I bought new stock from a different source entirely. All of them in my local shops were from the same supplier and apparently all were sterile.

It;s really impossible to tell for certain. I have seen breeding pairs of Discus breed for several years then stop when the lights were changed on the tank, or from being moved to a identical tank one space over in the breeders rack. No one knows why, they just did. It's part of what makes them an expensive fish, they aren't really easy to breed.

They next time he has eggs, he might want to remove them from the tank and raise them separately if keeping fry is important to him.

MM

Answer 2

Water changes are important and a sample of water can be taken to the fish store to be tested for a very small charge, discus need good water quality. If the eggs are removed to be brought up artificially then place an airstone near to them in the tank as this simulates the parents 'fanning' them.

Answer 3

Very few animal parents in nature take care of their young. What he should do is to take the eggs away from the parents the moment they are hatched(move the parents). Get a spare tank ready for the pregnant mother to stay in.

Answer 4

A lot of fish eat their eggs. I think it's survival of the fittest. There are a few pairs of fish that I have that have raised their young, but I'd say 99% of them either eat the eggs or eat the young when they hatch.