Amongst the most popular of freshwater tropical fishes are the family commonly known as Cichlids (Cichlidae), not only because of their beauty but also because of their variety.
Choosing appropriate Cichlids for your aquarium can be a tricky process because Cichlids can be aggressive, can eat other fishes, can attack each other and can be highly territorial. Understanding a little about the origins of Cichlids can help you to choose species appropriate to your aquarium.
Introduction to Cichlids
In this article, my aim is to give you an insight into the massive and intricate world of Cichlids (without getting particularly technical) in order to help you to understand more about these beautiful fishes. Where I need to use technical terms (because you are certain to encounter them elsewhere), I will explain what such terms mean in plain English because you, gentle reader, deserve to be able to distinguish between those who want to help you and those who want to baffle you with bulls**t.
Origins of Cichlids
Cichlids are a very ancient family of fishes. It is also a huge family of fishes. At the time of writing, there are around 1,700 distinct species of Cichlid but experts reckon that there are between 2,000 to 3,000 distinct species in existence.
Many millions of years ago (apparently around 550 million) there was a huge continent known as Gondwana. It included:
- South America,
- Central America,
- parts of the Middle East,
- Antarctica and
Over vast amounts of time, these landmasses drifted apart into the positions in which they currently reside. All of the continents are, in fact, floating over the molten lava beneath, in much the same way that a pie crust floats over the super-hot filling beneath (but without being in a pie tin).
It is believed that Cichlids developed on the super-continent of Gondwana, many millions of years before the existence of dinosaurs and this tends to be backed up by virtue of the fact that as Gondwana broke apart and island continents drifted away into their current positions (which continue to drift) it is almost exclusively the case that no Cichlids exist on any continents or islands that were not part of Gondwana or that have formed on islands since the “modern” continents became established. The exceptions are generally very few in number and where Cichlids are found in the wild (for example, in Florida) it is generally accepted that they were introduced.
Body shapes and sizes of Cichlids
Cichlids come in a huge variety of body shapes ranging from long, almost eel-like fishes, through shapes that we would generally accept to be “fish-shaped” to almost circular fishes (when viewed from the side) and that are pencil-thin (when viewed from the front or rear).
Adult Cichlids can be as small as one inch in length or grow to over three feet in length.
The unique jaws of the Cichlid
Most animals (vertebrates) have a jaw containing teeth. Carnivores have teeth that have evolved to tear apart meat. Cattle have teeth that have evolved to enable them to mash up grass. We humans have evolved teeth that enable us to eat meat, fruit vegetables and perhaps even pizza.
The Cichlid, over its epically long evolution, has gone one better in that it has two sets of jaws. The first jaws (known as mandibles) are where you would expect them to be – at the entrance to the mouth. The second pair of jaws (known as pharyngeal jaws) are in the throat (pharynx). This additional pair of jaws enable the Cichlid to be a very proficient and efficient eater simply because it has more chewing power. In practice, it enables the Cichlid to consume a wide variety of foods and do so with great efficiency.
The six fundamental differences between Cichlids and other fishes
In terms of the evolution of different species of fishes, there are six characteristics that differentiate Cichlids from other families of fishes. The differences are:
- The two sets of jaws (mandibles and pharyngeal jaws)
- Just one (as opposed to two) nostrils on each side of the head
- The absence of a bony shelf beneath the orbit of each eye
- The division of the lateral line into two parts (it is singular in other families of fishes):
- The first on the upper half of the flank behind the gills
- The second along the middle of the flank starting around half-way along and ending at the rear of the caudal peduncle (just before the caudal (tail) fin)
- An otolith that is shaped differently from other families of fishes (otolith comes from the Greek words, oto meaning ear and lith meaning stone). In essence, the otoliths enable animals to determine acceleration and deceleration, vertical and horizontal movement and rotation – a sort of gyroscopic sense, and
- The small intestine exits from the left side of the stomach, whereas other families of fishes have small intestines that exit the stomach from the other side.
In the main part, these differences enable ichthyologists correctly to classify existing and new species based upon these characteristic differences. For we mere mortals, understanding the basics is probably all we need to worry about.
What are the sub-families of Cichlids?
At the time of writing, there are nine sub-families of Cichlids that are recognized by ichthyologists. These families are as follows:
- This sub-family is found only in South America
- It is found in the Amazon, Orinoco, Paraná, and Paraguay River basins, and various rivers in the Guianas
- This sub-family comprises just 3 known species
- This subfamily of Cichlids is found in:
- the Greater Antilles (Cuba and Hispaniola),
- United States (southern Texas),
- Central America and
- South America
- This sub-family comprises around 260 species
- This subfamily of Cichlids is found in:
- This sub-family is native to South America
- This sub-family comprises around 117 species
- This sub-family is native to:
- Sri Lanka and
- This sub-family comprises around 16 species
- This sub-family is native to:
- This sub-family of Cichlids is to be found anywhere from Panama (Central America) in the north and as far south as Argentina.
- This sub-family has some evolutionary adaptations that enable fishes to sift invertebrates from silt
- This sub-family comprises around 200 species
- The sub-family is found in the Congo River Basin in Central Africa
- This sub-family comprises a single species
- This sub-family of Cichlids is found in the Middle East and throughout Africa
- It is a huge sub-family comprising over 1,100 species
- Retroculinae and
- This is a sub-family found only in tropical South America
- Three species are native to rivers in the southeastern Amazon Basin in Brazil
- One species is native to rivers in Amapá (Brazil) and French Guiana
- This sub-family is currently known to comprise just four species.
- This sub-family is found only in the lakes and rivers of Madagascar
- This sub-family was the most recent sub-family to be classified so appears out of alphabetical order of the other eight, previously classified sub-families
- This sub-family comprises just 14 distinct species.
In total, from the information provided above, a total of 1,710 species of Cichlid have been identified and classified at the time of writing. This number will significantly increase over time (perhaps).
Where you will find (and not find) Cichlids in nature
Cichlids will be found in nature in:
- Central America,
- North America (south of the Rio Grande drainage),
- South America and
- The Middle East
Cichlids will not be found in nature in:
- Europe and
- North America (north of the Rio Grande drainage)
Cichlids have been introduced as “exotics” (introduced species) in:
- Japan and
Where species are introduced into a new environment there is generally a tendency for the introduced species to destabilize the indigenous species and this can wreak havoc with the ecology of that region. It applies not only to species of fishes but also to non-native plants and for this reason, aquarists are urged not to let their aquarium stock get into the wild.
Are Cichlids good community fish or are they aggressive?
For the aquatic hobbyist, whether a particular species mixes well in a mixed aquarium is of vital importance because the individual invests a great deal of time, effort and money in creating a harmonious environment that is enjoyed both by the hobbyist and, indeed, by the community living within the aquarium.
There is a basic guide that we can draw from nature which, as a general rule, should be taken into consideration. This rule is that larger fish tend to consider smaller fish to be fair game as a source of food.
The next general guide is to find out, before going to your pet store, as much as you can about species of fish that you are going to purchase because you need to know how big they will grow, how long they will live, whether your aquarium provides the correct living conditions for them and more about the temperament of the species.
If you are keeping species that are one inch in length with species that are six inches in size then you need to be fairly certain that the large species is not about to treat your Neon tetras (for example) as a snack.
Elsewhere in this blog, in respect of individual species (and tetras are a good example), I recommend that when breeding them, the adults should be removed from the breeding tank because they will eat their own young.
Cichlids are generally extremely good parents, far better than other species of fish. Cichlids are egg-laying fishes – some lay eggs in caves, some in the substrate, some are mouthbrooders. In general, Cichlids will protect their young.
This, of course, will tend to make Cichlids territorial in nature. To protect their young they are likely to drive away other species to the extent that they may attack them.
Some Cichlids will attack and eat smaller fishes and some Cichlids can be aggressive towards each other. It is often the case that males will use aggression to determine the hierarchy amongst the group. When this occurs, the dominant male will show richer, deeper coloring, whilst the submissive males will become paler. In this scenario, it will tend to be the dominant male that mates with the females and the submissive males will play a rather more supportive role.
Are Cichlids monogamous or polygamous?
The short answer to this is that some Cichlids are monogamous whilst others are polygamous.
In general, Cichlids that lay their eggs in caves or in the substrate tend to be monogamous in nature whilst mouthbrooders tend more towards polygamy. Note that this is a generalization and not an absolute rule and there are exceptions in both instances.
How do mouthbrooding Cichlids breed?
Mouthbrooding Cichlids have evolved their breeding ritual over many millions of years.
Typically, when a mouthbrooding female lays her eggs she will then immediately gather them up into her mouth. The problem with this is that the eggs are not yet fertilized.
In order to fertilize the eggs, the male has evolved spots on (in particular) the caudal fin that, to the female, look like eggs and the female will attempt to gather up these “eggs” as well.
When the female is gathering up these “eggs”, the male will gyrate his anal fin and this will draw the female towards the egg spots. In doing this, the mouth of the female is brought very close to the genital papilla of the male and the will deposit his sperm in the mouth of the female, thus fertilizing the eggs.
Species of Cichlid that take the eggs into the mouth are known as ovophile mouthbrooders. They will also tend to keep the fry in their mouth for several weeks after the eggs have hatched even though the fry have become free-swimming in order to protect the brood from predation.
Some open-brooding and cave-brooding Cichlids will, once the fry have hatched, keep the fry in their mouths until they have developed sufficiently to survive alone. Such species are known as lavophile mouthbrooders.
It is generally the case that it will be the female Cichlid that mouthbroods.
How do open-brooding Cichlids care for their young?
Angel Fish and Discus are two examples of open-brooding species of Cichlid. Open-brooding Cichlids lay their eggs on leaves, logs, rock or in the substrate.
In general, the female will waft water over the eggs and remove dead or unfertilized eggs in order to maintain the health of the eggs in general whilst the male will patrol to ward off other fishes that may have a taste for caviar – many species will eat fish eggs and fry – including their own.
The roles are interchangeable so the male may tend to the eggs whilst the female patrols.
Once the eggs are hatched, one or other of the parents will lead the fry, as they grow, guiding them to food whilst the other parent will watch over them.
How many eggs does a Cichlid lay?
Assuming a single spawning, the range of the number of eggs laid in a single spawning varies from species to species. Cichlids can lay anything from fewer than 100 eggs in a single spawning to 1,600 or more eggs.
How do cave-brooding Cichlids care for their young?
Cave-brooding Cichlids are secretive in the laying of their eggs. They may choose to lay them in a cave (natural or otherwise), in a crevice, in an unoccupied shell, on the underside of logs or similar, The pair will then guards the eggs until hatched and subsequently work together to help to find food for their young.
Such Cichlids have been observed turning over leaves and generally rooting around to discover sources of food for their young.
What will Cichlids eat?
As previously detailed, Cichlids have evolved both mandibular jaws and pharyngeal jaws. Having two sets of jaws makes them highly efficient and flexible feeders. Such evolution allows for:
- Algae scraping,
- Insect-eating (insectivores),
- Eating other fish (piscivores),
- Plankton eating (planktivores) and
- Snail crushing
Cichlids also enjoy eating plants.
In general, a mixed diet of live, freeze-dried and flake foods will be ideal for your Cichlids and they will also browse on any organic matter within their aquarium.
How long do Cichlids live in an aquarium?
In general, Cichlids will live for eight years or more in your aquarium. That said, it is not uncommon for the Cichlids to live for anything up to twenty years, given an ideal environment and diligent care.
If you elect to keep Cichlids then please consider this to be a long-term relationship.
What Cichlids should I consider for a community tank?
Choosing Cichlids that will be good community fish can be tricky. Choosing the wrong Cichlids can wreak havoc in a community tank because the wrong species can predate on its tankmates.
Since the males are more aggressive than the females then it would be sensible to maintain a ration of one male to three females because you don’t want males to be competing for the favors of the females, as this will significantly heighten the aggression in the tank.
The following species would be my top ten choices for a community tank. Please note that I am not suggesting that you include all ten species. It would be prudent to include just one or two species:
- Agassiz’s Dwarf Cichlid – Apistogramma agassizii
- Angelfish – Pterophyllum scalare
- Blue Acara – Andinoacara pulcher
- Bolivian Ram – Mikrogeophagus altispinosa
- Discus – Symphysodon
- German Blue Ram – Mikrogeophagus ramirezi
- Keyhole Cichlid – Cleithracara maronii
- Masked Julie – Julidochromis transcriptus
- Rainbow Cichlid – Archocentrus multispinosa
- Tiger Severum – Heros serverus
Please check out my articles on each of the species listed to ensure that you are choosing species that are appropriate for the size of the aquarium that you have for the adult size of each species.
A well-planted aquarium that looks natural, perhaps including “bogwood” and floating almond leaves (to provide shade) and, perhaps, caves or tunnels fashioned from well-positioned stones or half of a clay plant pot.
Top 10 community Cichlid video
We aquarists tend to have different preferences in the choice of species that we would recommend so here is a video from another aquarist showing his top ten cichlids:
What Cichlids should I avoid placing in a community tank?
There are many Cichlids that, because they are aggressive, very big, predatory or any combination of these traits, you should avoid including in any community tank. The following five are what I would consider to be my top five popular cichlids to avoid including in a community tank but are ideally suited to an appropriately sized and laid out single-species tank:
- Convict Cichlid – Amatitlania nigrofasciata
- Frontosa Cichlid – Cyphotilapia frontosa
- Jack Dempsey Cichlid – Rocio octofasciata
- Jewel Cichlid – Hemichronis bimaculatus
- Oscar Cichlid – Astronotus ocellatus
Summary of the Beginner’s Guide to Cichlids
The world of the Cichlid is both ancient and extremely complex.
Cichlids can be superb community species or, if you make the wrong choices, can devour your community in short order.
Cichlids can range from one inch to more than three feet in length so be certain that you understand what the adult size of the tiddler in the pet store will become.
Cichlids can be monogamous or polygamous and understanding your chosen species will enable you to make appropriate choices.
Cichlids are long lived so take this into account when choosing to keep Cichlids.