This article was written to give some thought on the behavior of breeding discus fish and their fry. Not much detail has been documented on this aspect of discus keeping which almost seems over looked. Discus fish are remarkable creatures (such as other cichlids) and we owe them the time to try to understand why they do what they do.
I am first going to tell of a particular experience I had with two breeding discus pairs and explain thereafter what some theories are as to why certain things took place. Ready for this fascinating story?
The first pair being discussed we will call pair no. 1. The male had some bad habits that were upsetting at the least. He encouraged fungus to grow on the spawn killing alot of fertile eggs. The eggs that did hatch, he attached the fry to the fungus. He had an even worse problem. The female wasn't allowed to tend the eggs if they were fertile nor allowed to tend the fry. Her eyesight was off thus accidentally eating the good eggs instead of the dead ones. He took notice of this and aggressively chased the female away. If this wasn't upsetting enough, once the fry reached the age of two days old after hatching, he would eat the fry no matter how many hatched.
The second pair involved (we will call pair no. 2) were the absolute opposite since their first spawning. They kept the spawn free of fungus, shared everything and went as far as to brag about their new lives by swimming to the front of the tank where someone was standing. They also would not eat their fry even if only 3 hatched! Both these pairs come from the same breeding line.
As we can see, there are certain questions to these problems. Why did the male in pair no.1 do this? The water was healthy enough to sustain the fry so what else could it be? These pairs both shared the same water so it had to be something else. We will now address what was done to solve the problems that existed. It was not going to be an easy task.
On the pair no.1's ninth spawning, I decided the male must be removed The female was left to tend 153 eggs alone which did not allow for much success rate. I also needed to consider that her eyesight was off which also lessened the chance the fry's survival. She never had the chance to rear fry previously.
Medication was added to prevent fungus. I removed the infertile eggs as an added bonus to deprive that hairy fungus from their food source. Well, an error occurred. Eight eggs were accidentally dislodged from the site. Quickly they were put in a separate container until hatching occurred! After these eggs hatched, they were given back to the mother to be with their siblings.
While watching the female tend the spawn, I noticed not once did she make contact with them by mouthing them. When the fry started to leave the site, they did not show any indication of association with their mother and most turned out to be too weak to swim. The mother let them detach from the wood at their own pace not once putting them back until they were strong enough to swim. She watched these poor belly sliders and did nothing. She did not even attempt to gather them or mouth them to stimulate the doomed fry. If they were human, I'd bet money she was confused as to why her fry are acting this way. She never once attempted to eat her offspring.
The fry from pair no.2 were relocated leaving only three with the parents. This pair's young were seven days old. Five fry were removed from the female in pair no.1 and syringed into pair no. 2's tank. This female quickly caught wind of the new presence and sucked them into her mouth. She spat them out a few seconds later. Good! She accepted the fry! But wait! She once again sucked them up but did not spit them out. The experiment at hand failed.
About 2 minutes later, she spat the fry out again. They not only began to swim, but they also fed from her! Success! She was trying to stimulate them to the point of which the young fry could feed.
After this thrilling experience, the rest of the fry were slowly added. She waited by the corner that the fry were put into displaying erect fins. Once all the fry were with her, the male caught wind of their presence. He immediately started to squabble with her wanting the fry for himself. This went on for quite some time.
Finally, the pair agreed the male was to tend to the fry that were not swimming and the female's job was to gather those fry that scattered throughout the tank. The male continued to mouth the fry until all were up and swimming. This was truly an amazing sight (by the way, the fry all lived and are now growing to the point of sexual maturity!).
After all the fry were placed with pair no.2, the male from pair no.1 was put back with his mate. Three days later they spawned making this their 10th attempt. I was surprised to find out that their attitudes towards each other had changed drastically.
The male stayed his distance away from the spawn only tending to them when the female allowed it. The female must have learned to compensate for her lack of proper eyesight since she never once missed her mark. This pair became the ever loving parents I never thought possible.
Another delightful thing to see was not seeing a thread of fungus or dead eggs being allowed to stay on the sight. They mouthed their young like pros and went as far as to let the fry live and feed from them! How did this change occur? Well, maybe we just don't give these fish enough intellectual credit or there is some instinctive behavior that kicks in when all else fails. There is also another possible reason at least on the male's part about eating the fry.
This particular male had been overly picky about the chemistry of the water. It had to be almost to a point of being sterile for him to rear fry in. Alot of pairs will eat their spawn if they sense any toxins in the water or the fry become sick. But some are just too picky even if the water is healthy.
Some of the changes that took place within this pair are uncertain. Upon observation it looks as though they have a not so limited learning ability. It is said that cichlids are intelligent! Seriously, Not allowing the fungus to grow after 10 spawns, had to do with the female. She started to take excellent care of the problem. It was observed that the male patiently looked at the female when she did this. He in turn reciprocated the action.
The female's compensation for improper eyesight is still being observed. This female has always had a bit of a problem with that. When she suddenly corrected this problem, it was a shock to say the least. It looked very clear she has learned to acknowledge her problem and quickly deal with it. How she abruptly did this is not known.
Another sight to see was how they mouthed the young tentatively and did not let the fry swim free too soon. The fry in turn totally associated with the parents and immediately fed from them upon release from the site. This pair now has parenthood down to a science!
I have observed that if the pair does not mouth the fry, periodically take one into their mouths to "chew" on them and after spit them back onto the site, the fry do not learn to acknowledge the parents as a food source or as protection. The fry will then scatter throughout the tank and swim away from the parents when trying to be caught. Also, the signals the parents display to the fry when it's time to gather the stray young is ignored. Everything that is done has it's unique purpose for the survival of the offspring.
I had done more experiments after the dilemma of this pair had been solved. The lights were turned off so all the fry in the pairs' tanks would scatter. When the lights were turned back on, the pairs that did not mouth their young much had a heck of a time gathering the fry together. They tried to catch their offspring, "chew" on them, and spit them out so the youngsters would stay with them. This took a while to accomplish. The pairs that had done an excellent job in mouthing the fry before they swam had no problems gathering their family together. They simply swam up to the young and in turn, the fry went immediately to their parents for protection. This was done with fry of all ages. Of coarse the older the fry, the easier it is for the parents to collect them.
Whether this article is about instinctive behavior or learned, one thing is clear. Each and every action has it's purpose and that purpose is for the survival of future populations. It doesn't matter if we try to associate their behavior with human behavior. Their reasons for doing what they do are working for them. We simply interpret these behaviors to our own so we can try to understand what makes them tick which in turn helps us to better take care of our world and everything in it. Whether we think any kind of animal is less intelligent then us or visa-versa, that is not the issue. We must remember that everything has a reason to be on this planet. We therefore must not look upon these precious lives as a dollar value. Life is far more valuable then a piece of paper that is man made!