Cichlid Aggression - How to Reduce Aggression

Published March 01, 2008 - RSS/XML Feed

By Robert Lashlee

African cichlids are a favorite among aquarists due to their interesting behavior, relative ease of breeding for many species, and bright coloration. However, many cichlid aquariums end in disaster due to poor planning. Proper planning is required because many of the species native to the rift lakes of Africa are very aggressive. While this aggression can never be fully eliminated (and who would want to? – it is one of the things that make these fish so interesting), it can be reduced such that you do not come home one day to find half your tank wiped out.

The main methods used to reduce aggression include combining fish with similar size and temperament characteristics, combining fish with different coloration and patterns, appropriate feeding, combining fish that occupy different levels in the aquarium, providing enough horizontal space, providing adequate cover, sexing your cichlids, overstocking, and rearranging your aquarium.

Similar Size and Temperament

African cichlids can vary widely in their adult sizes. This is important to remember because most are sold as juveniles and they all look the same size at this stage in their lives. You need to do some research before you buy any species so you can make sure not to combine a species that will reach 10” with one that will reach 4”. If you do not do the research, the 4” fish will become a snack.

It is also important to ensure that the species are of similar temperaments. If you combine a highly aggressive species with a rather docile one, the aggressive one will make quick work of the other fish. However, if you combine two aggressive fish, they will both be able to fend for themselves and no one will end up being picked on.

Different Coloration and Patterns

In the wild, African cichlids tend to look at others within their own species as competitors. They will often leave other species alone while constantly harassing their own. Cichlids look at the color and patterns of other fish to see if they are the same species. For instance, if you have demasoni (a black and blue striped cichlid from Lake Malawi), it would generally be unwise to combine it with other blue fish or other vertically striped fish, especially when the other fish have these characteristics, but do not have the aggression of a demasoni.

There are thousands of cichlid species with a multitude of colorations and patterning so you should have no problem finding species that differ in these two areas.

Appropriate Feeding

One of the major reasons (besides mating) that cichlids are so territorial is due to food. If they find that food is scarce, they are more apt to be aggressive and guard their territory. If food is easy to find, their aggression is reduced somewhat. Now, this is not meant to endorse overfeeding. Instead, it is a reminder to stick to your daily schedule of 2-3 feedings with each occurrence lasting several minutes. Many people also consider it a good idea to fast their fish for a day every so often. Just be sure not to feed your fish sporadically or aggression in your tank could increase.

Occupying Different Levels in the Aquarium

While it is true that many African cichlids occupy the bottom of the aquarium, there are different species that live in alternate zones. In nature, there are fish that live along the rocky shores and there are ones that swim in the open waters. There are also ones that live on the sandy bottom. If you set your tank up to include each of these regions, you may find that the fish will not stake out the same territories. This will obviously reduce the amount of aggression in the tank.

Adequate Horizontal Space

If the cichlids you choose mostly occupy the bottom of the aquarium, horizontal space will be at a premium. For this reason, having a great deal of vertical space does little to reduce aggression. Instead, it is better to have a shorter tank that is long. The extra length will allow you to provide multiple caves along the bottom of the aquarium and each individual fish should have enough space to carve out his own area. If the fish are not forced to fight for prime real estate, they are less likely to be aggressive towards each other.

Adequate Cover

If you keep species that are native to a rocky biotope, it is important that you provide them with numerous rocky areas in the aquarium. This will serve two purposes. First, it will provide them with numerous caves so they will not have to fight over a few. Second, it will provide fish that are being harassed with cover so they can escape the dominant ones. It also simulates their natural habitat which they are sure to appreciate.

Sexing Your Cichlids

Many of the aggression issues are between males during mating times. Usually a dominant male will emerge in your tank and he will fiercely drive away any other male competition. Therefore, it is often a good idea to limit the number of males in your tank. This cannot be done for every species as sexing some cichlids is very difficult. Other species, however, are not that hard and in these instances, you should try to limit the male population. You generally want to provide each male with a small harem (mix 2-3 females per male). The male will chase the females relentlessly when he is ready to mate. If you have a 1:1 male to female ratio, the male will chase the one female until she dies. If he is forced to spread his chasing around, the females have a chance to rest before being chase again.

Overcrowding

In general, cichlids should be overcrowded. Overcrowding helps to curb aggression by making it difficult for any particular fish to focus on another one. With so many cichlids in the tank, it is difficult for the dominant ones to single out individuals. This spreads the aggression out to many fish which means each individual fish is not too stressed.

However, you must be careful when overcrowding a tank. You will need extra filtration to handle the extra load and you will need to be very regular with your water changes.

In terms of what overcrowding means, let us look at an example. Suppose you have a 58 gallon aquarium. Now, typically you would want around 58” of fish if we are to go by the oversimplified rule of 1” of fish per gallon of water. If we stock it with fish that reach an adult size of 4” then we can expect to pick up around 14 fish. Now, say you pick up three or four more. Now you will have 68”-72” of fish. Notice that we did not add a huge amount over the recommended, but we did add a few more to pack the fish in the aquarium.

Rearranging Your Aquarium

It is a good idea to rearrange your tank every time you add a new cichlid species. If you do not do this, the established cichlids will already have their areas picked out and will fight the new fish that are unfamiliar with the territorial boundaries. By rearranging the rock work, each species – old and new – has an equal chance at securing a territory.

It is also not a bad idea to periodically rearrange the rock work even when no new species are being added. Some people do this every 2-3 months as it helps to break up any territorial strongholds and seems to reduce aggression to a certain degree.

It is also recommended that you introduce the least aggressive species first as you build up your tank to its full stocking.

Conclusion

Not all cichlids are the same and it is unfair to group them all into one behavioral group. However, the vast majority of the African cichlids are very aggressive and this article is meant to provide some tips on curbing this aggression. While it is important to research any fish you purchase, it is especially important to research any cichlids you are going to buy. As should have been clear from this article, picking the wrong species can be devastating to your aquarium.

Further Reading

For additional information, refer to the following web pages:

● http://www.cichlidae.com/article.php?id=12

● http://www.cichlidrecipe.com/crp6.htm

● http://www.malawicichlidhomepage.com/aquainfo/african_cichlids_harmony.html

Read Related Freshwater Aquarium Articles

All About Tropical Fish Tanks: An overview of tropical fish tanks, what they are, and the pros/cons of keeping one.
Planted Aquariums: An overview of the different styles of planted aquariums. Different types of plants you could use. Popular plants.
Choosing a Planted Aquarium Substrate: Learn about the factors you should consider when choosing a substrate for your planted aquarium.
Setting up a Freshwater Fish Tank: Information on choosing a fish tank and how to set-one up!
Choosing a Freshwater Aquarium Substrate: Learn about the factors you should consider when choosing a substrate for your freshwater aquarium.
Choosing the Right Filtration System for Your Aquarium: Learn about the different types of filters for your freshwater aquarium.
Properly Aerating Your Aquarium: Learn the basics of aeration and how to properly aerate your aquarium.
Adding Rocks and Wood to Your Freshwater Aquarium: Learn about the things you should consider when adding rocks and wood to your aquarium.
Aquarium Decorations: Types of decorations. Tips on decorating your tank. Online sources
Heating Your Freshwater Aquarium: Learn about different heater options for your fish tank.
The Process of Cycling a Fish Tank: What is "cycling" your fish tank? Why is it important? Instructions for how to do-it.
Freshwater Fishless Cycling: Learn about new methods for cycling your freshwater aquarium without fish.
What Are Good Freshwater Fish For Beginners: What makes a freshwater fish a good candidate for beginners?
Stocking Fresh Water Fish Tanks: Learn how to select the right quantity and combination of fish for your freshwater aquarium.
Acclimating Fish - Drip Method: Learn how to properly acclimate your fish to your aquarium using the drip method.
Properly Maintaining the pH in a Freshwater Aquarium: Learn how about pH and how to properly maintain it in a freshwater aquarium.
The Natural Environments of African and South American Cichlids: Learn about and how to recreate the natural environments of African and South American Cichlids
Common Freshwater Tropical Fish Diseases: Learn about common fish illnesses and how to effectively treat them.
Breeding Freshwater Fish: Learn how to succesfully breed freshwater fish.
Breeding Mouth Brooding African Cichlids: Learn how to succesfully breed mouth brooding African Cichlids.
Controlling Algae Growth: Learn why algae grows in your tank and how to control it.
Using Carbon in a Freshwater Aquarium: Learn about the differing points of view and guidelines on using carbon in your aquarium.
Fish Tank Maintenance and Cleaning: Tips and instructions for maintaining a healthy fish tank.
Choosing and Conditioning the Water in Your Aquarium: Learn about how to properly choose and condition the water you use in your freshwater aquarium.
Water Testing in Your Freshwater Aquarium: How to test your aquarium's water, and what to look for.
Keeping Goldfish: Advice on keeping Goldfish.
Fish Bowls: An overview of keeping fish in a fish bowl. A brief history. Pros and cons.
Wall Mounted Fish Tanks: Advantages and disadvantages to a Wall Mounted Fish Tank. Installation. Accessories.
Freshwater Fish Article Database: Articles on dozens of different freshwater fish and appropriate care.
Freshwater Plant Article Database: Articles on different freshwater plants and appropriate care.
View All Articles