Frequently Asked Questions

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Updated: December 9, 2007

Certain questions pop up quite frequently. Here are some answers to some of them.


  1. Which kind of cichlid do I have?

    Go to my "Identify a Cichlid" page and see if that helps. If it doesn't try and email me a photo of the fish. Even a poor photo is better than none. If you don't have a photo, try and describe the fish as best you can. Keep in mind that there are over 2300 species of cichlids, and many of them look alike, so pay particular attention to colors, stripes, bars, spots on fins and body shape when describing your fish.

  2. I need information on parrot cichlids

    Go to my page on parrot cichlids.

  3. Are all cichlids one species?

    No, there are many, many species of cichlids (at least 2300 species). People confuse the idea that there are so many kinds of cichlids with the idea that there are so many kinds of dogs. They are not the same. There are many species of cichlids, whereas there are many breeds of dogs. All dogs are one species and as such, any kind of dog can theoretically breed with any other. This is not the case with cichlids. The many kinds of cichlids are separate species in the sense that a robin and bluejay are separate species of birds. This does not mean, however, that different species of cichlids cannot breed with each other in an aquarium (see my page on hybrids).

  4. Why are my cichlids so aggressive?

    In comparison with certain other common aquarium fishes, many people find cichlids to be rather aggressive fish. Often one cichlid will chase other fish and possibly even kill other fish. Why? Cichlids live in a tough world and they have to be tough to survive and breed. Much of the aggression cichlids display has to do with either maintaining a feeding territory, obtaining a mate, or defending offspring.

    Some cichlids in the wild have a feeding territory, i.e., a region in the lake or river space that it tries to keep all to its own. Another cichlid entering that space must be driven off. In a small aquarium, there may simply not be enough space for feeding territories for more than one or two cichlids.

    One of the things that makes cichlids so interesting, namely their parental care, is also what makes them so aggressive. Field work in the new world tropics shows that the number of predators is so high and the frequency of attacks so great that a brood of young cichlids has little chance of surviving each night. Parents must remain vigilant and fiercely fight off all manner of predators.

  5. What can I do to control aggression?

    You cannot make a cichlid non-aggressive, but you can control its aggression. Fish, like many animals, often use natural objects in their surroundings to mark the limits of a territory. If you put two fish in a barren aquarium, you are bound to have lots of fighting because there are no objects to define boundaries. If you put a single nice rock in one corner, both fish will try to claim it. If, however, you put something like a row of rocks or plants down the middle of the tank, each fish will likely stay on one side or the other of this barrier (assuming the two fish are roughly equally matched). The more objects you put in an aquarium, even if they don't go completely from the bottom to the top of the tank, the more easily the fish can divide up the space.

    Some people go the opposite route. If there is absolutely nothing in the tank, then there is nothing to defend. This is why fish stores can often keep very high numbers of fish in a small tank. Plus, with so many fish, a dominant fish can't zero in on a weaker fish and terrorize it -- someone else always gets in the way. The danger of this kind of setup is that it requires a lot of filtration, and worse yet, if one fish dies but isn't removed, you can have a rapid cascade of death where all fish die in a matter of days or even hours.

  6. How many cichlids can I keep in my tank?

    This question is really another way of looking at the previous question. In other words, the number of cichlids you can keep in your tank depends on a couple of basic things: how large is the tank, how much filtration have you got on it, and how structurally complex is the tank? As stated above, a bare tank, no matter how large, can hold very few cichlids without one of them killing all the rest. On the other hand, a very complex 20 gallon tank, with lots of wood and plastic plants, can house a dozen 2 inch cichlids, provided you do regular cleaning of the filter and lots of water changes. I don't suggest keeping that many fish in a tank of that size, but it is possible.

    What is structurally-complex? Basically, as a rule of thumb, if you can't see the back of the tank (assuming your water is clean), I would say your tank is structurally complex. A single cave in the middle of a tank is not structurally-complex. Unfortunately, the items needed to make a tank structurally complex in a natural-looking way, namely plants (live or plastic), wood and/or rock, tend to be expensive. In fact, they can add up to far more than the fish and tank. The good news is that except for live plants, these other items will last for a decade or more, so consider them an investment.

    There are cheaper alternatives if you can sacrifice a little on looks. PVC pipe is extremely inexpensive ($5 will buy 10 feet or more). Rinse it and cut it into sections (six inches or so depending on the size of your fish). PVC tubes make great hiding places. Clay flower pots are also good for this. If I am having a problem with aggression in a fish tank, I immediately dump in three or four small (3 inch) bottomless clay flowerpots for weaker fish to hide in. These are also very inexpensive, typically less than a dollar.

  7. Which fish would make good companions for my cichlids?

    This again depends on the structural complexity of your tank. In a bare tank with a large cichlid, virtually nothing else will last long. On the other hand, in a very complex tank, you can keep a number of other fish with certain cichlids.

    Of coure, you aren't going to be able to keep any small fish with an oscar or other highly predatory cichlid -- these cichlids eat other fish for a living so putting in a tetra or a swordtail is just giving them an expensive lunch. They will appreciate it, but you might not be so thrilled and neither will the tetra or swordtail.

    However, with many cichlids, adding a lot of structure opens up the possibilities. Catfish are particularly good companions for many cichlids -- catfish tend to be fairly tough and are often hiding during the day but active at night; the opposite of most cichlids. I have had Raphael catfish living with various highly aggressive cichlids for almost a decade.

    Plecostomus do well because of their armor. Keep in mind that some species of plecostomus are highly aggressive towards members of their own species , e.g., royal plecos and others grow very large (over a foot) so choose carefully.

    Tetras can sometimes be kept with fish like angelfish and other New World cichlids. I have a very, very structurally complex tank (155 gallon) with eight adult discus, five adult angels and about 250 tetras. They live in different parts of the tank and get along fine. This tank has a dozen large pieces of wood in it, and you can't see even the back third of the tank.

    When your cichlids breed, however, you may not be able to keep any other fish in the tank with them. Many species of cichlids, even ones which are relatively docile most of the time, become extremely protective of their young (which is one of the reasons many people keep cichlids), and simply will not tolerate other fish nearby that might pose a threat to the kids. I have seen a pair of kribensis (2 inches long ) with fry keep a bunch of adult Texas cichlids ten times their size cowering at the end of an aquarium for days on end. Parental cichlids are a force to be reckoned with.

    Another way of viewing this is as follows. If you are keeping cichlids which tend to breed readily, such as convict cichlids, don't try to keep other fish with them at all, because as soon as the convicts start to think about breeding (which can be as soon as half an hour after putting them in the tank) they will most likely kill the other fish to make the tank safe for convict babies.

  8. My cichlids just laid eggs, what do I do?

    The good news is that you don't really have to do anything, other than enjoy watching the parents do their thing. Once the fry become free-swimming, about 7-9 days after the eggs are laid, depending on the temperature, you can start to provide special food for the fry. You don't have to, particularly if the tank they are in has a nice crop of algae, but if not, consider feeding the fry newly hatched brine shrimp. Check here to find out how to do this.

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