THE PROS AND CONS OF ARTIFICIALLY HATCHING
 AND FEEDING OF DISCUS FISHES
By Jim E. Quarles
16-02-2000

Few other subjects about discus culturing brings about more interest from the small or hobbyist breeder. Some are 100 % sure it’s the only way to go and others are 100% sure it is a bad idea. Both have their reasons for taking each position. The purpose of this article is to expose the subject to the light of reasoning and not unfounded passion one way or the other.

Why it’s not a good idea first.

When this subject comes up most of the time the less then informed will offer totally non-scientific statements like. " If you do this then the fry will not be able to side feed or feed normally after a few generations! Well let’s take a scientific look at that augment.

To be at all reasonable we must assume that discus fish are also subject to Mendels laws of genetics. If your not willing to accept this quit reading for you will not understand or like what follows.

Mendel’s work shows that.

• Each parent contributes one factor of each trait shown in the offspring.
• The two members of each pair of factors segregate from each other during gamete formation.
• Males and females contribute equally to the traits in their offspring.
• The Blending theory of inheritance was discounted.
• Acquired traits are not inherited.

The last law was high lighted and put in italic for a reason since this law of nature goes right to the false argument that if the fry don’t learn to side feed from the adults this trait will not be passed on to their offspring. If this were so then Mendel's law would not be true. Side feeding is an acquired trait. It is a learned behavior pattern, and therefore can not be passed by genetic method.

THE PASSAGE OF GENETIC TRAITS THROUGH FEEDING
IS TOTALLY UNFOUNDED AND CAN NOT BE
SCIENTIFICALLY SUPPORTED.

THE STATED POSITION THAT SPAWNING DISCUS CAN TELL GOOD FROM BAD GENETICS IN ANY GIVE SPAWNING IS ALSO NOT SCIENTIFICALLY SUPPORTABLE.

The statement sometimes made that adult spawning discus sometimes eat their eggs or fry because they know them to be genetically defective is also rather foolish no such factors can be demonstrated as factual. This statement must fall under the heading of " the old wives tale " type of thing. While it might be possible for spawning fish to react to strange or injury movements among a group of fry this is highly unlikely and can not be supported by the frequency of such events. Other disturbing factors are far more likely to trigger such actions such as water conditions or other physical events in or near the spawning site.

THE ON BIG DIFFERENCE BETWEEN THE NATURAL WAY OF FEEDING AND THE ARTIFICIAL WAY OF HATCHING AND FEEDING MUST BE JUDGED SOLELY ON THE BASES OF NUMBERS OF FRY THAT RESULT.

With the proper use of artificial hatching and fry feeding you can expect to see a very much larger number of fry that can be kept alive and growing to the stage of any culling that might need to be done. In fact by using artificial feeding you can expect to see about an eight five to ninety five percent increase rate that live as opposed to perhaps an average rate of forty percent if you allow the parents to hatch and feed the young fry.

This brings us to the sometimes offered statement that with natural hatching and feeding the weak and less desirable fry fail to feed and are lost. I have been asked to believe that somehow the good ones have a better chance of finding the feeding surface of the adults. This might be true if we only consider the physically weak or deformed fish with defects in their swimming abilities but does not prove that just as many perfect fry are also lost during the natural feeding process for one reason or another. I don’t think you can place much faith in the process of natural selection when it is applied to a captured breeding process. There are far too many other factors that can explain these losses, nor do I believe you can show that they are selective to poor fry.

SO WHAT ARE THE ADVANTAGES
TO ARTIFICIALLY FEEDING FRY?

The answer to this question bags another question. To what purpose are you breeding the fish? Is it to obtain the highest number of fry so that you can select from a larger number, which increases you, genetic pool? (Experimentation) Are you breeding to increase the total number of fry to select for sale? (Commercial Production) Perhaps you are spawning the fish just for the fun of doing so (strictly a hobby effort) with no need to consider numbers in the make up of the result?

As one who has produced fish in large numbers both ways over a long period of time I can state that there is no scientific reason why artificially fed fry should not be just as good at natural feeding later in their lives then those that were feed the natural way. Also I see no scientific reason why this aspect of discus culture should not be practiced by anyone who is looking to increase the total number of fry they can produce to use for any other purpose in the trade or hobby.

So for the present you can regulate all the stories you hear about this changing the genetic make up of the fish to the category of an " AN OLD WIVES TALE TOLD BY THE UNINFORMED."