Aequidens and "Aequidens"




Aequidens has long been a catch-all group used for fish with three anal spines and a resemblance to the Aequidens from South America. There have been fish that even amateurs could see that this can not be right. So when Dr Sven O. Kullander came along with his revision of the Genus Cichlasoma in 1983 he also made a revision of the Genus Aequidens. He split it into several groups which later became new Genera. CLEITHRACARA, Kullander & Nijssen 1989. LAETACARA, Kullander 1986. KROBIA, Kullander & Nijssen 1989. GUIANACARA, Kullander & Nijssen 1989. BUJURQUINA, Kullander 1986. TAHUANTINSUYOA, Kullander 1986.

The known Aequidens and the doubtful "Aequidens".

There are still several new Aequidens that will come and hopefully the different Aequidens species will be described.

Well when I find time, I will lay out new information about my dear Aequidens. I have collected several Aequidens and with good help from fish friends I have got my hands on several others. In the menu below you can click on the names and jump directly to the fish you want to see and read about.

LATEST NEWS: There has been published a new Genus where many of our old Aequidens have moved to. The new Genus is Andinoacara and came out in 2009. One of our Aequidens sp. has also been described.
If you want to read the description, just follow this link: pdf




Aequidens epae. Kullander, 1995

A male Aequidens epae.

This Aequidens belongs to our newer fish. I know that Rainer Stawikowski collected it in Brazil in Rio Tapajòs in 1992, so the fish was in the collection at the Museum for not so long before it was described by Dr Kullander in August 1995 and the paper was published in `Ichthyological Exploration of Freshwaters', Volume 6, no. 2.

He described three species and the other two were Aequidens michaeli and Aequidens gerciliae. Aequidens michaeli is here on my website already, because I got the fish in 1990. But Aequidens epae was new to me, and probably for you too.

A female Aequidens epae.

I got this fish from a good friend of mine, namely Ingomar Kranz in Germany. When I got the fish it looked like many of the Aequidens when they are small, dull color or rather grey. But, like many of these fish, they become very nice fish when they grow up. I think that I will not try to describe the color when the fish grow up or are about to spawn. I think it's better you look at the photos and make up you own opinion, but in my eyes they look great.

The biggest fish is a male and my three males are about the same size, the female is smaller. The fish is easy to keep, a temperature around 26°C, pH around 7 or a little lower. The hardness on the water is no problem as long as you avoid exstremes, my water is around 2 dH. I feed the fry with newly hatched Artemia, and a good water quality is also important — that goes for all fish, and is easily done by changing water.

The fish comes from Brazil and from the Rio Tapajòs river system. Well there is not much more to tell ... if you have experience in keeping cichlids from the Genus Aequidens, you should not have any problems with this fish. The only problem is to get the fish.



"Aequidens" sp. Choco

A half-grown Aequidens sp. Choco collected out in the Choco Province in Colombia. This fish also reminds me of the Aequidens coeruleopunctatus, from Panama.
This is an adult female "Aequidens" sp. who was collected out in the Choco Province in Colombia. The photo was taken in one of my aquariums when she was guarding eggs.

Many times photos do not give full credit to the fish, but I hope these give you an idea of the fish.

This fish is also placed in Aequidens pulcher group. I hope that in the near future that all Aequidens will get a name, or a new genus. But in the meantime we can keep and enjoy the fish in our aquarium.



Aequidens metae, Eigenmann, 1922


This is an old favorite in the hobby, it's easy to keep, easy to breed, and eats almost everything you give it. And, it's also very tolerant when it comes to the water.

This fish was first described in 1922 by Eigenmann and was collected in Colombia in the Rio Meta river system, this has given the fish its name. The type locality is Barrigon in Cano Carnicera and Cumaral. Other known places are near Villavicencio and Puerto Gaitàn. The distribution of this fish is bigger than thought in the begining, so you will find the fish in slightly different colors etc. The holotype that Eigenmann described was 155 mm. and the paratype was 168 mm, but I have had bigger fish than that.

Many fish grow bigger in the aquarium. They usually get food every day, and no predators. They can eat and enjoy themself in the aquarium. People who do not know the fish, will easily think of Aequidens tetramerus when they see Aequidens metae, and there is not that big a difference between them, especially when the are smaller.

If you wish to read Eigenmanns description there is a lot of information to get. You just have to visit the Library and ask if they can get you a copy: `Memoirs of the Carnegie Museum', Volume IX, No 1. `The fishes of Western South America, Part 1', page 241 (Æequidens metæ sp. nov.) By C. H. Eigenmann, 1922.



Aequidens michaeli, Kullander 1995

A pair of Aequidens michaeli caring for their eggs.

This fish was described not so "long" ago, but I kept the fish long before it was described and we used name Aequidens sp. "Rio Xingu". The fish was brought to Europe from Brazil in 1988 by Bernd Kilian, Ulrich Schlieven and Rainer Stawikowski. They had collected the fish in Rio Xingu, near Altamira. So that is why the fish was called Aequidens sp. "Rio Xingu" in the beginning.

I got some small fry from my friend Rainer Stawikowski in 1990, if I recall right. The fry were eating well and grew up to be really nice fish, as you can see in the photos. It took some time before they, as adults, decided to spawn, but in the end they did. They are not difficult when it comes to food, they eat whatever you give them, and that goes for most of the Aequidens.


Aequidens plagiosonatus, Kullander 1984.

Aequidens plagiosonatus was described by Dr. Kullander in 1984 and the fish is known from the upper and easter part of Rio Paraguay near Caseres, Descalvados, Itiquira, Coxim and Miranda.

The fish is not exactley colorful but for me very interesting. The fish is not very difficult to keep, but is very shy and will be easy scared. Temperature, pH and dH is as for most of the Aequidens. They don't like to be looked at when they have spawn and eating up the eggts very quickly. Then you must take the rock or the log they have spawn on and put it in a small tank with a weak air supply.

The eggs will hatch after about 4 days on a temperature around 26 degrees, and the fry is freeswimming after about a week. The fry is easy to feed with newly hatched artemia.

Aequidens plagiosonatus
Here a pair had spawne.


An adult male and you can see that the fish is not excactly a rainbow, but for people like me working with Aequidens it's interesting.






Aequidens pallidus, (Heckel, 1840)

Aequidens pallidus.

Aequidens pallidus is not well-known. When I got them for the first time I thought it was Aequidens metae. I checked different books and magazines that I had and they said this was Aequidens duopunctata. But I did not agree with this because the photos showed another fish.

They grew up and were more than 15 cm. Two of the photos show the first fish I had. They were changing colors after the mood they were in, and looking at the photos they can differ a lot.

The fish is a substrate spawner, that means they spawn on a small stone, or on a bogwood or if they find another material they will use. In older literature they say that the fish is a delayed mouthbrooder, but I did not get any confirmation that the fish was larvophile when I had them. I spent a lot of time in my aquarium room and I think I would have seen it if they were larvophiles. There was no indication that they were delayed mouthbrooders. So I meant to keep a better eye on the fish when they were about to spawn, but they did not do that.

So it took many years before I saw the fish again. I got some small fry from my friend Rainer Stawikowski. I visited an importer in Sweden and when I looked through all his tanks, I came to some large tanks with several thousand Paracheirodon axelrodi, or Cardinal Neons as we call them. Among all these Paracheirodon axelrodi there were some small cichlids. I asked where the Cardinal Neons came from. Was it Colombia or was it Brazil? He said that the Cardinals came from Brazil, and so I asked him if I could buy these small cichlids and he said yes.

When I came home and put the fish in a tank, I could see that it was an Aequidens, but nothing more, they were too small. Well, there was nothing to do but just feed the fish well and wait until they grow up. Today the biggest fish is around 13 cm, and I am the owner of Aequidens pallidus again.

So now I just have to be patient and hope they will pair-off and lay eggs. I don't know where in Brazil these fish came from, but in the literature they say that the fish comes from the lower and middle reaches of Rio Negro, Rio Preto da Eva, Rio Urubu and other tributaries belonging to the Rio Negro water system.

The fish is not difficult to keep and it eats most of what you give them. Earthworms are a snack it will eat huge amounts of, and will in the end, lay on the bottom and gasp. Temperature between 25-30°C, is good, I've kept the fish with plants too, large Amazon Sword plants Crinum thaianum Giant Vallisnera and Microsorium.

The fish I have now is a little different in colors, and I will take new photos to compare with the old ones. As I said earlier the fish can change a lot in color, you will see that from the photos. The fish I have now does not change color so much, but it's a beautiful fish.



Aequidens patricki, Kullander 1984

ABOVE: Aequidens patricki male.

LEFT: Aequidens patricki female.

A female with eggs.

Aequidens patricki is one of the really nice Aequidens, and it has very nice colors. But ask me why I keep these small "grey" fish?

The color is not everything when you keep fish, but if it has nice colors, then this is not a minus, and Aequidens patricki is such a fish.

Aequidens patricki comes from Peru in Rio Aguaytia and Rio Pachitea and was described in 1984. When I read the description with photos (I got a copy from Dr Kullander) I thought that it would be a long time before this fish would swim in my aquarium, but I got the first fish from a German fish friend quicker than expected.

The fish grow to a size around 11 cm for the female and about 15 cm for the male. This fish could be a little bit more aggressive than many other Aequidens, especially against congeners. That is no problem, but the tank needs to be at least 150 liters or bigger, with a lot of bogwood and rocks to make hiding places for the fish that will be chased, then you can keep several fish together. The fish is rather tolerant when it comes to the water, but a pH around 7 or lower is good. The dH can be 0 or higher.



Aequidens rondoni

Aequidens rondoni.



"Aequidens" sapayensis (Regan, 1903)

A large male Andinoacara (Aequidens) sapayensis.

I got this Andinoacara (Aequidens) sapayensis from my good friend in Copenhagen, F. Ingemann Hansen early in the 1970s, and he had got the fish from Germany. The fish had come from a tributary of Rio Cayapas with the name Rio Sapayo. I don't have a map that is so detailed that I can find it, but it should be close to Rio Santiago on the west coast of Ecuador near the city of San Lorenzo.

I did not have time to check this out in 2003 and to go out to San Lorenzo, to find the Rio Sapayo, but I am quite sure I will be going to Ecuador again, in a combination visit to another country.

A female Andinoacara (Aequidens) sapayensis with eggs.

This fish might belong to what we called "Aequidens" pulcher-group, and may remind some of Aequidens sp. "Choco" or Andinoacara latifrons, but you can also compare it with Andinoacara ("Aequidens") coeruleopunctatus. The fish is easy to keep and is also easy to breed, but I have not seen it for a long time. So we have to find the fish again and find out if the name is valid or what. So I guess I need to go to Ecuador again.

The fish in the photo below here was also sold as a Blue Acara, but as you can see the fish is not very blue, but brown. No-one remembers where this fish came from. Now the fish is around 10 cm and has layed eggs. The fish reminds me of a fish we called Aequidens sapayensis in the 1970s (look at the photo above). I will keep a close watch on the fish, but there are several things to be sorted out, so I guess, Ecuador here I come. I need to find Rio Sapayo and see if the fish is there.

A female of what that might be Andinoacara (Aequidens) sapayensis(?).

Above is a photo of a female that we believe could be Andinoacara (Aequidens) sapayensis. Compare this photo with the other female higher up on this page. I am at least not quite but very near to believing that these fish could be the same fish. It's very frustrating to have a fish and not know where it originated from.



Aequidens sp. "Maracaibo"

We call this fish Aequidens sp. "Maracaibo" and they say this fish comes from Lago Maracaibo in Venezuela.

I was in Lago Maracaibo for the first time in 1965 and had a swim near a place called Puerto Mirranda. The water was very turbid and suddenly I felt something was picking at my toes! I walked backwards up to the shore and there where the water was very low so I could see what it was, it was a fish (cichlid) that was picking at my toes. This could possibly be the fish in the photo, but I had nothing to collect with, so I am just guessing about what kind of fish it was. So I guess I have to go back to find out what it was. But it's a nice fish, right?

Aequidens sp. "Maracaibo"male.



Aequidens tetramerus, (Heckel 1840)

Quisto Cocha type.

Aequidens tetramerus (Heckel 1840) is one of the bigger Aequidens. It can at least grow up to 20 cm. Males have longer dorsal and anal fins and also a little bit stronger color. The fish has a reputation for being a little quarrelsome, but my own experience with this fish does not confirm that. Not more than others; it is a cichlid.

You can't place this fish in a 50-liter tank together with several other fish, then you are asking for trouble. You can't expect them to behave nicely in a crowded tank.

The fish has a large distribution, it goes from Peru in the west through Ecuador, Brazil, Colombia and to Guyana in the east. I will show you some photos of the different Aequidens tetramerus. The first photo is of a A. tetramerus from Peru, given to me by Dr Kullander in 1983. He had collected the fish in a Lake near Iquitos with the name Quisto Cocha. He said then that the fish was Aequidens uniocellatus. Later he said that the fish was a synonym of Aequidens tetramerus.

ABOVE: This one is also an Aequidens tetramerus from Peru. Originally I had two A. tetramerus from two different biotopes in Peru, but I have just one now and I'm not certain if this one comes from Rio Ucayali or from Rio Nanay(?).

I think the nicest one is the one from Ecuador. I collected it outside Lago Agrio and also in Lago Limon Cocha.

Aequidens teramerus, no matter which one, is an easy fish to keep and spawn. But that does not mean you do not have to change water or feed it well. The fish will pay you back with nice color and good behavior.

ABOVE: A pair with eggs.

BELOW: This last one, I collected in Guyana; this one is more greenish in color.

The Aequidens tetramerus is easy to keep, they eat most of what you feed them, also easy to spawn. Just give them a good water quality by changing some of the water every week. They don't eat plants, at least that I have noticed, but they can move them. So I would suggest 5-6 small ones to start with in a 160-liter tank. When they start to make pairs, then leave the pair alone in the tank and remove the others.



Aequidens diadema (Heckel 1840)

ABOVE: Female in the forground and the head of the male.

BELOW: An Aequidens diadema male.

The Aequidens diadema appears in the hobby from time to time.

My fish were just pairing-out when it happened: the heater did not work well and I boiled all my A. diadema, so I can't give you any information about breeding.

The typesite of the fish is in a small river near Marabitanas in Brazil in the upper Rio Negro close to the border with Venezuela.



Aequidens tubicen, Kullander & Ferreira 1990

Aequidens tubicen from Brazil.

This fish comes from Rio Trombetas in Pará Brazil. I will not try to explain to you the color of the fish, the photo should indicate the colors on adult fish. The fish reach a SL of about 12 cm and prefer fast-flowing jungle streams with clear water. It prefers also a low pH.

I have not been able to breed the fish so far. So you have to settle for the photo of the fish, at least you know what it looks like.



Aequidens sp. "Rio Atabapo"

Here we are going up Rio Inirida to explore some of the lower tributaries of Rio Inirida.

One of the first we went up was Caño Aguajon. The water was a little turbid, but clear enough to snorkel there and catch fish. In the river we found, for the first time, an undescribed Aequidens which we also saw in other tributaries and also in Rio Atabapo. So we called it Aequidens sp. Atabapo.

The water was turbid and the fish very shy, so I could not come very close, but you can see the Aequidens and also Mesonauta insignis.

I took some underwater photos, but they are not very good.

You can see what the biotope in Caño Aguajon looks like. The bottom layer was fine sand and a little layer with mud above. Some places there was also an accumulation of leaves on the bottom. Especially used by the small Apistogrammas who were hiding under it.

Aequidens sp. "Atabapo".

Newly captured specimens (above left) were very dull in the color. But when I came home with the fish and it was settled down in the aquarium, the color started coming. I think you will agree that it is a very nice fish when you look at the photo on the right.

Rainer Stawikowski and Uwe Werner state in their book `Die Buntbarsche Amerikas', Band 1. that this fish is a delayed mouthbrooder. I have not bred the fish so I can't tell. My plan was to go to Colombia in March 2005, but I was warned against going to Colombia for the moment. I hope it will cool down so I can go to this lovely country again.



Aequidens sp. "Jenaro Herrera"

Aequidens sp. "Jenaro Herrera" female guarding eggs and you can see the male up on the right.

These fish have been in the trade for a while, coming and going, and have been mixed with the Aequidens diadema. It's a beautiful fish when it is adult, but can look rather drab when smaller.

This goes for many cichlids, they do not have a nice appearance before they are adult, and this takes about two years. So if you have no patience, find something else.

I will highly recommend the genus Aequidens, there are a lot of nice fish there, just scroll up this page and be convinced.



Cichlid Power,



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under the International Code of Zoological Nomenclature.