Why are Discus Fish so Aggressive??

Discus Fish are considered a good community fish.  They very rarely will chase or bully other species of fish in the tank.  The one exception I have found is they sometimes do challenge Angelfish, but by far and away, most of the time they ignore them.

In an established tank with no new Discus added in several months, they will usually be generally calm around each other and the only interaction will be a larger one chasing away a another one that comes to close and is smaller, but close to the same size.

There are two exceptions. 

First, when two Discus Fish are getting ready to spawn or have recently already spawned, they will aggressively chase away any fish that get into their spawning space.  The male is the most aggressive as the female will be  cleaning the spawning surface.  Once the eggs have been laid, the roles reverse and the female becomes the most aggressive.  This is just a general rule and the aggressiveness can vary from couple to couple.  While they will chase any other fish away, they will most aggressively chase away other Discus, especially males.

Second, when the pecking order is disrupted, they will bully until the pecking order is again established.  Firmly establishing a pecking order can take several months, sometimes even up to 6 months.  Most of the fighting is between fish of the same or close size.  Large Discus generally will mostly ignore other Discus Fish that significantly smaller than them.  That is one reason why we often recommend adding smaller fish and not ones that are larger or of the same size.

The good news is, while the fighting may seem intense, Discus Fish will almost never kill each other.  The biggest concern is that the smaller ones do not get enough food.  We recommend that you feed at both ends of the tank at the same time. We also recommend that one of the feedings is at night with the lights off.

Discus Fish can range anywhere from $15.00 for a juvenile common Discus Fish such as a Red Turquoise at an online store to over a Thousand for a fully mature very rare Discus such as an Albino Platinum Long Finned Discus.  A proven breeder pair of Long Finned Albino Platinum Discus Fish could cost around $10,000.00.  You will find the starting point for Discus Fish at your local fish store is around $50.00 if you can find them at all.

1) ALL SPECIES OF PLECOS ARE DIFFERENT! Some like muddy, hot, slow moving water (Stripes Peckoltia). Some like crystal clear, fast moving water that is a little cooler (Blue Panaque).

2) All Plecos have different food requirements. Some eat algae. Some are carnivorous. Some are scavengers. Some eat wood. Most will eat a combination of the above.

3) Some Plecos can be aggressive to other fish, especially slow moving or sick ones. The most aggressive are the Gibbiceps. Royals can also be somewhat aggressive to each other, but rarely to other fish.

4) Many Plecos can grow quite large, so make sure that you have enough aquarium space for them to grow into.

5) Coloration in Plecos can be remarkably different within a species, depending on the region where the Pleco was caught.

6) Most plecos show some characteristics of chameleon like color changes depending on their background (the L060 Lyretail Chameleon Pleco and the L110 Red Spot Bristlenose are good examples), so keep that in mind when you set up their aquarium.
7) Many, if not most, are good community fish.  Ones we recommend the most to keep with slow moving fish such as Discus and Angelfish are the Bushy and Bristlenose.  Some of our other favorites are Striped Peckoltia, Snowball, Clown and Royal Plecos.

8) While it does seem to be counter intuitive, Plecos can be jumpers, especially the Bristle and Bushy nose.  We recommend keeping the water tanks with Plecos about an inch and a half below the rim.
9) The best Internet reference for Plecos is Planet Catfish who’s link is http://www.planetcatfish.com/core/

We feed our Discus primarily Beef Heart Flake, but supplement it every day with other Flake and Freeze Dried Foods.  The Multi Pack is great way to get started.  As for the Freeze Dried Foods, I would start with the Brine Shrimp.  Once your Discus get larger, you should switch to Earth Worms.  Larger Discus also like Glass Shrimp.  Beef heart Flake is extremely high in protein (higher protein than most other flake foods).  It is also fortified with Vitamins and Minerals, and you will find your Discus like it more than any other flake food.  Your juvenile Discus will grow significantly faster when they are fed Beef Heart Flake.

Please feed your Discus three times a day, morning, noon and night.  The nighttime feeding should be with the lights out.  Discus are naturally nocturnal grazers.  If there is some bullying or aggression in your tank, please feed them at both ends of the tank.  Feed them as much as they can eat in 10 minutes.  They should be kept with some Corydoras Catfish, Plecos or Loaches to eat any food uneaten by the Discus.

Please go to this link:   http://www.somethingsphishy.com/discus-and-angelfish-food-c-41_67.html 

If you are acclimating new fish into a tank, please do not feed your new Discus for 24 hours.  As we detail in the Acclimation Instructions, you should not feed your new for fish at all for the first 24 hours after delivery.  Any food given will likely not be eaten and can end up clouding the tank.  After the stress of shipping, they will typically have no appetite.  Feed them very little for the first week as they will still have little appetite.  Over the next few weeks as they get used to their new home, they will slowly get their appetite back.  You can increase the temperature to 88 degrees to speed up their metabolism and increase their appetite.

Please do not feed your fish live or frozen Blood Worms.  Hexamitia is sadly a relatively common disease in Discus.  They can carry the deadly disease Hexamitia and freezing does not kill the Hexamitia Cysts.  Hexamitia is an internal parasite that can positively diagnosed by your fish showing long white stringy feces and they over time will become emaciated.  It is hard to treat and is contagious.  The cysts can lie dormant in the gravel and one of the only way to kill the cysts is to empty all fish and plants out of the tank, add bleach and let it for 24 hours and then do a complete water change every day for three days. 

Freeze Dried Blood Worms are fine.

**Discus Age and Size**

Discus in an aquarium will typically live around 8 years, but some can live to 10 years old.  There is some evidence that keeping the temperature at the low end of the range for Discus at around 80 degrees will slightly increase their longevity. 

In a 120 gallon or smaller tank, Discus will typically grow to 6-7 inches.  In a larger tank that is very clean and when you feed them properly three times a day with high protein food like beef heart flake, they can grow to around 8 inches.  Having some current will also have the slight effect of them growing larger.  Despite some misinformation on the internet, males and female will usually grow to approximately the same size.  It is not uncommon for wild Discus to grow to 9-10 inches.  I have heard stories and even seen pictures of wild Discus that a reported to be 12 inches, but I have never seen one with an actual ruler next to it, so I cannot verify if that is correct.

Artificially raising Angelfish is actually very easy and if you are looking to have the highest survival ratio it is definitely the way to go.

We raise the fry in 5 gallon tanks. Getting the water correct is very important.  You should take water out of the spawning tank right before transferring the eggs and put it in the 5 gallon tank.  The temperature of the tank they are coming from and the one it is going into has to be the same.  A difference of even a couple of degrees will kill the eggs.  Clean water is absolutely essential for hatching the fry as if the water is at all dirty, fungus will form on the eggs. That is one reason that keeping the spawning tank water extremely clean is so important.  To assist in keeping fungus from forming, we do two additional things.  We add Methylene Blue to the water.  Add enough to turn the water a deep blue.  We also run heavy aeration next to the eggs, creating a current, which helps to stop fungus from forming.  When the tank is ready and all the above conditions are met, quickly take the eggs out of the spawning tank and place them into the rearing tank.  They should not be out of the water more than 10 seconds.  Just a heads up, the spawning Angelfish will be very unhappy about you taking their eggs out.  They will attack your hand and while it really does not hurt, it can be quite startling.  To reduce that, I usually tap on the opposite end of the tank to distract them then quickly reach in with my other hand to take the eggs out.  Hopefully the eggs will be on a breeding cone or something else that is very easy to remove.  If the tank they are coming from is a ways away from the tank they are going into, I use a 2 gallon bucket full of water from the spawning tank to move the eggs into before I move them to the rearing tank. 

Once the fry become Free Swimming at around 6 days, you will need to feed them within 24 hours. You should set up a Brine Shrimp hatchery on the fifth day so you can feed them newly hatched brine shrimp within hours of them becoming free swimming.  They will not eat much at first and you do not want to foul the water adding two much.  As the size of the spawn will vary significantly, how much you feed them will be somethings you have to decide when they hatch out. Feed your new Angelfish baby Brine Shrimp for three weeks.  After three weeks start cutting back on the baby brine shrimp and when you feed them add in some finely ground flake food.  Between 3 weeks and 5 weeks, slowly decrease the Brine Shrimp and increase the flake food until after the fifth week, they are eating only flake food.

After 5 weeks, you will need to transfer them to a larger tank. When Angelfish are crowded in a tank, their growth gets stunted.  They will grow VERY slowly to not at all if left in a small 5 gallon tank.  The size of the tank they need to be moved into depends on the size of the spawn.  Spawn size can be from just a few to a couple of thousand.  I once had a spawn of 2400 from one silver pair.  Black and Silver Angelfish usually have the largest spawns.  Young pairs typically have relatively small spawns, but the size of the spawn will increase as they mature.

In our next issue, we will go over naturally raising the fry.