The Cockatoo Dwarf Cichlid (Apistogramma cacatuoides)

Author: Mike Hellweg

An experienced aquarist profiles the smaller-sized, but by no means smaller-personality, cichlids that get their name from their beautiful cockatoo-crest-like dorsal fins.

Intriguing Cockatoos

The genus Apistogramma is one of the most popular genera of cichlids among advanced hobbyists. There are some species, such as A. elizabethae and A. iniridae, that give even the most experienced breeders fits, but there are also some species that are so adaptable that over the last several decades, breeders have been able to fix a number of different color variants.

One of the most spectacular species is called the cockatoo dwarf cichlid (A. cacatuoides) or sometimes just plain “cacatuoides.” They have become so popular that they are produced in quantity on Southeast Asian fish farms and are regularly available in the trade, even in big-box stores. In the past couple of weeks, I even noted some juvenile triple red cacatuoides at a local big-box store on sale for just $4 each!

The common and scientific names both come from the spectacular dorsal fin of the male. “Cacatuoides” means “like a cockatoo,” and it is an apt descriptor. The first several rays of the male’s dorsal fin are greatly elongated and are often carried erect, resembling the display crest of a cockatoo.

The wild fish don’t have the spectacular colors of domestic line-bred fish, but even their fins are spectacular. Line-bred fish with a solid red or orange dorsal have to be seen to be believed. A displaying male will catch the eye of even the most jaded hobbyist.

A Bit of History

The cockatoo dwarf cichlid was first imported into the hobby in the early 1950s and has been a fixture ever since. At first it was known as Apistogramma “U2,” which stood for “unknown #2.” We like to think that the letter-number system for undescribed species is a recent invention (think L-numbers for plecos or C-numbers for Cories), but hobbyists were using it for dwarf cichlids more than 60 years ago!

A. cacatuoides was formally described by the Dutch ichthyologist J. J. Hoedeman in 1951 and has kept that name ever since. At times, it has been mixed up by hobbyists and dealers with A. borellii, another apisto that is spectacular and easy to care for, but that has been, for the most part, cleared up.

As males reach sexual maturity, they develop an enlarged head that seems like it continues to grow throughout their lives in all disproportion to their body size. Their mouths are huge and are used for yawning threat displays to other males. I’ve even heard experienced hobbyists declare that there’s “something wrong with that male’s head.” There was nothing wrong—it was just a fully developed, sexually mature male.

In the Wild

A. cacatuoides is found in Peru, Colombia, and Brazil in the drainages of the Rio Ucayali and Rio Solimoes. This part of the Amazon drainage has fluctuating water parameters that, at certain times of the year, are harder and more alkaline with a higher pH than those we usually associate with South America in general and the Amazon River basin in particular. At various times of the year, the pH can rise up to 8.0, hardness can vary from unmeasurable to what we would call very hard, and alkalinity fluctuates from zero to well over 300 ppm!

Cockatoo dwarfs are found in both white water and clear water, but not in blackwater habitats. This makes them especially adaptable to tap water here in the US, and they do spectacularly well in most hobbyists’ tanks without us having to do anything to make the water suitable for keeping or breeding.

Heaters are even optional as long as the room doesn’t get too cold in the winter, as they can tolerate temperatures much cooler than most apistos, down to the low 60s Fahrenheit (high teens Celsius).

Contrary to what we would expect from the generic apisto, cockatoo dwarfs seem to do better at the lower end of the range and not as well in warmer water. In the wild, they are found in smaller bodies of water, such as small streams and lakes, and are often found in backwater puddles at the end of the dry season, making them ideal candidates for the aquarium. And so they are.

Aquarium Care

Cockatoo dwarfs, like most dwarf cichlids, are bottom-oriented. This means the footprint of the tank is much more important to them than the overall water-holding capacity. A long, low tank is preferable to a high or display-type tank. In other words, a 20-gallon (76-liter) long is preferable to a 20 high, and a 30-gallon (113-liter) long or 33-gallon (125-liter) extra long is preferable to a 29-gallon (110-liter). A “breeder” style tank would be even better. My favorite tank for a group of cockatoos is a 30- or 40-gallon (113- or 151-liter) breeder.


Cover the bottom with a thin layer of fine gravel or even sand. Add a couple of pieces of driftwood with epiphytic plants like Anubias or Java fern attached, a couple of caves (new ceramic or plastic flower pots or even coconut shells with a hole cut in them), and a clump of Java moss.


Choose whichever filter you prefer, as you are more likely to service one that you like and are comfortable with. I use sponge filters or mattenfilters in all of my tanks, even my 125- and 135-gallon (473- and 511-liter).

Water Requirements

As I mentioned earlier, there is no need for a heater as long as the room temperature doesn’t go below 60°F (15°C) for any length of time. If you absolutely have to have a heater, set it for 72° to 74°F (22° to 23°C).

As said before, your local water is probably fine for the very-adaptable cockatoo apisto. Instead of focusing on hitting an exact pH or hardness number, realize that in the wild, these numbers fluctuate throughout the year and hitting an exact number isn’t that important for cacatuoides. What is important is to do large, regular water changes to keep dissolved organic compounds and nitrogenous wastes in check.

I like to do a 50-percent water change every week to 10 days, though with my travel schedule, that sometimes stretches out to once every 30 days. But with just eight cacatuoides and some small livebearers as dithers in the tank, the bioload is very light and doesn’t build up very quickly in a 40-gallon (151-liter) breeder.


A. cacatuoides is not very picky when it comes to foods. I feed live foods every day, but I also feed flakes, pellets, and frozen foods several times a week to give them a varied diet. They take every food I add to the tank.

In order to bring them into breeding condition, I feed them live worms several times a week. I currently use live blackworms and chopped earthworms, but Grindal worms and white worms will work, too. They will also take daphnia, live adult brine shrimp, and small cherry shrimp. Surprisingly, even adults will take newly hatched brine shrimp.

They are also miniature eartheaters, especially the males. They spend much of their time digging into the sand, sometimes up to their eyes, looking for food. They’ll pop up with a mouthful of sand, move it around their mouth, and carefully squirt it out through their gills, extracting any food items as they find them.

Whenever fry are present in the tank, I always squirt newly hatched brine shrimp and microworms into the tank near the fry at least twice a day. The fry will also graze on the surfaces of the plants, nibbling at the nutritious biofilm (aufwuchs) that grows there.


The cockatoo apisto is a cave spawner. You should always keep at least as many caves as there are females in the tank. I like to add a couple extras just in case. The openings should not face one another, and the caves should be staggered around the tank with other dÉcor in between to break up the line of sight and give each female some privacy.


The males will fight amongst themselves until one establishes his dominance. He will be the breeder. The other males likely won’t get a chance to breed and will likely be beaten up each time they venture into the open in sight of the dominant male. It is easy to tell which male is dominant—he will be out in the open, in full color, courting the females. Usually he won’t have any torn fins.

The sub-dominant males will take on a pale coloration, keep their dorsal fins clamped, and stay on the lookout for an escape route. For the sake of the fish, the sub-dominant males should be removed unless the tank is heavily planted and rather large (over 75 gallons [284 liters]).

Behavior Can Be Unpredictable

Remember that each fish is an individual and breeding behavior can be unpredictable. I’ve seen a single male quickly kill his rival males and successfully court a harem of four females in a bare 15-gallon (57-liter) tank that was supposed to be a temporary quarantine tank, and I’ve seen two pairs successfully raise their broods together in a 75-gallon (284-liter) planted tank, one pair on each end of the tank.

Courting and Displays

After a short courting period, during which the male dances and displays for the female, the female leads the male to her chosen cave. Courting and guarding females take on a beautiful lemon-yellow and black coloration. The female lays her eggs on the side wall or ceiling of the cave, and the male fertilizes the eggs.


As the male can sometimes be twice the size of the female, often he can’t enter the cave and has to fertilize the eggs from outside the opening. Fertility is usually high, and the female will pick off any unfertilized eggs. Some authors report batches of up to 200 eggs, but most spawns that I’ve had averaged closer to 100 to 125.


The female guards the fry night and day until they are free-swimming and for several weeks thereafter, herding the fry around the tank and taking them from one feeding place to another. Java moss is a favorite feeding site, as it is usually home to a vast number of microscopic critters. They also find the surface of sponge filters or mattenfilters to be great grazing areas. The young grow quickly and can begin coloring up at just eight to ten weeks old.

My Experience

When I was a kid back in the early 1970s, I bought my first fish book, Rosario La Corte’s Enjoy Your Cichlids, and read it cover to cover many times over. I think I learned more from that book than any other I’ve ever read, save Innes’ classic Exotic Aquarium Fishes. Anyway, at the bottom of page 27, there is a picture of two gorgeous male A. cacatuoides displaying for one another. I was hooked (excuse the pun), and for the next almost 30 years, that fish haunted my memory.

Although I’ve found wild populations with some blue on the body and fins, I still haven’t found any quite like those unbelievably beautiful males in Van den Nieuwenhuizen’s picture. I continue to look.

I finally had a chance to get some wild fish back in 2001 and bought my first group of A. cacatuoides. It was a group of 1-inch (2.5-cm) juveniles, and the seller claimed it was four pairs. Well, it was eight fish, four of each sex, but pairs? As it turned out, no.

I put them into a 15-gallon (57-liter) quarantine tank with a large sponge filter, a shallow layer of fine quartz gravel on the bottom, a big clump of mixed Java fern and Java moss, and a half dozen ceramic caves and coconut shells scattered on the bottom. One male, just slightly more colorful than the others, quickly asserted his dominance. By the end of the second day when I got home, there were three corpses bobbing in the current.

Protecting the Females

The four females were each in a cave of their own, and the single remaining male was out in the middle, looking like he was still wanting a fight.

To protect the females and give the male something else to watch, I added a group of five young Xiphophorus clemenciae adults to the tank. That seemed to do it. The swordtails’ activity calmed that male down and seemed to embolden the females. Within hours, they were out eating, and within three weeks, I had my first spawn—about 35 fry.


I carefully siphoned about 20 fry out of the tank and left the rest with mom. She did a great job herding and raising those fry. After that, at least one of the females seemed to always be herding a group of fry. The fry were easy to raise, as they took newly hatched brine shrimp, microworms, and powdered fry food from the start. Oddly, the ones left with the mother grew more quickly than those I moved to a separate tank to raise on their own.

I’ve since noticed that with many cichlids, so much so that now I try to leave most of the fry with mom and just remove enough to ensure I get another generation in case something goes wrong. I raised several hundred fry to maturity from that group and had first generation (F1) and later F2 juveniles or pairs to sell and share for a couple years afterwards. That was one of the first apistos I successfully kept and bred, and to this day, it is still one of my favorites, though I’m still looking for some to rival those I saw in my first fish book.

A Great Starter Cichlid

The cockatoo apisto is a great first Apistogramma for beginning cichlid breeders to work with. They are colorful, intelligent, excellent parents, and well suited for community tanks. If you have a good relationship with a local store, they will often take cockatoo dwarfs in trade for other fish, food, or equipment.

I do feel I have to warn you, though. The members of the genus Apistogramma are fantastic fish and it is easy to fall under their miniature “cichlidy” spell. I speak from experience! Since I got that first group of A. cacatuoides, I haven’t been without Apistogramma in my tanks. I’ve usually got at least three or four species swimming in my fishroom tanks at any one time. You’ve been warned. Now, go get some and enjoy!

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