Green terror cichlid (Aequidens rivulatus)

Green terror cichlid (lat Andinoacara rivulatus, syn. Aequidens rivulatus) is a very bright colored fish and its body is covered with bright blue scales. But this is not all about her rich color, it also behaves in a very interesting way. Green terror is a common name for all three sub species: Andinoacara stalsbergi, Andinoacara sp. Gold/Silver saum and Andinoacara rivulatus.


This kind of fish is often mistaken for another very alike fish – Aequidens pulcher.

There were the times when these two fishes were considered as one kind. However, nowadays they were divided into two different kinds. Although the fishes are alike, they have some significant differences.

Is rather large fish and in the wild fish max size can be about 25-30 cm (10-12 in), when Aequidens pulcher max size is just about 20 cm (8 in) in the wild.

Reproductive male has rather visible rounded hump on its head, whereas Aequidens pulcher male hump is rather less pronounced.

In addition, this fish is rather more aggressive then the Aequidens pulcher.

Green terror care is rather easy since it isn’t a demanding fish. But still it’s recommended for experienced aquarists, since the fish is demanding to water parameters and it requires qualitative feed.

Also as it is always true as for the large cichlid fish – this one is rather large and aggressive, it needs a spacious tank.

While fish is young it can successfully grow with other cichlids, but as it grows it becomes more aggressive and it’s better to keep the fish with tank mates that are aggressive and large, too.

Habitat in the wild

Aequidens rivulatus was first described by Gunther in 1860. The fish inhabits in South America: in river basins in the West of Ecuador and Central Part of Peru.

You won’t find this fish in wellhead parts of rivers, where pH is rather high due to the presence of ocean water. Inhabits both in quiet backwaters and in flowing sections of rivers.


It’s a large and heavyset fish and in the wild its max size is about 30 cm (12 in). In a tank the fish is usually smaller – about 15-20 cm (6-8 in).

The body glitters with blue and green metallic, the dorsal and fluke have an orange line on the edges, the face is patterned with stripes and spots of blue and green color.

Males are larger then females and they have elongated dorsal and pectoral fin, pronounced orange stripe on the fluke edge (some species have an orange stripe up to 1 cm wide) and the stripes pattern on their face is more consistent.

Fish lifespan is about 7-10 years, but we also have data that it lives longer.


Difficulties in keeping

Although it is a very beautiful fish that attracts aquarists, still it can’t be recommended for beginners.

Green terror cichlid is a large, aggressive fish and to keep it in a tank it has to be rather spacious. Couple can literally speaking terrorize its tank mates. Tank mates should be of the same size and of the same aggressive temper.

In addition, the fish is rather sensitive to water parameters and their abrupt change. Due to these facts, green terror cichlid can be recommended only to the aquarists who are experienced in keeping of large fishes.

However, beginners can also take care of green terror successfully, but only if they are able to create the proper conditions and to choose proper tank mates.


Is omnivorous feeder and it eats all types of feed, but it can be demanding. In a tank green terror feeds both on live and frozen blood worm, tubifex, white worms, brine shrimp, gammarus, crickets, worms, fish fillet, prawns and mussels meat, feeder fish like goldfish and other rich feed.

Modern pellets for large cichlids is rather good to provide healthy nutrition for the fish and additionally diet can be varied with live feed.

I myself give some of this food to my pets and as for the rest I’ve heard and read lots of good reviews.

Yet, all of the food is of high quality and it is the best one for this fish kind as well as it keeps the tank water clean.

Keeping in a tank

Just like all South America large cichlids green terror requires a spacious tank with clean water.

For couple a tank of 100 gallons capacity is recommended. In case if there are some tank mates the tank size should be larger correspondingly.

Green terror is sensitive to water parameters and it’s better for them when the water isn’t hard (5 – 13 dGH) with neutral pH (6.5-8.0). It’s obligatory to use a powerful external filter and to control nitrates and ammonia level in the water.

Tank should be moderately lighted and the tank design should be typical for large cichlids – rocks, snags and sandy bottom. It’s better not to put plants in the tank since cichlid tends to dig the tank bottom and change it according to its preferences.

Scientific NameAndinoacara rivulatus, syn. Aequidens rivulatus
Common NameGreen terror, gold saum
Tank size100 gallons (400L) and more
Temperature20–24 °C (68–75 °F)
Size30 cm (12 in)

Compatibility and tank mates

Space is a crucial thing for all large American cichlids, besides it is in the spacious tank where their level of aggression decreases.

Is a rather battlesome fish which will provoke its tank mates itself. However, it all depends on the fish temper and tank conditions.

Some fish when reaching their reproductive stage become more peaceful. The same is about green terror family – it is recommended to keep one couple in a tank to avoid fights. Often female is more aggressive then the male and she is sometimes kept separately from others.

During the spawning period the fish gets completely crazy and it’s better to keep them apart from each other. You can’t keep green terror cichlid with small african cichlids (like mbuna), since the latter will be either killed or they will be stressed all the time.

It’s better to use the following large fishes as green tank mates: oscar fish, flowerhorn, managuense cichlid, Jack Dempsey.


Male and female don’t have much differences. The male has an orange stripe on its fluke, it’s larger in size and it has a rounded hump on its head which the female doesn’t have.

The female feature is that as a rule she is more aggressive then the male, especially during spawning period. Usually, all other fishes act the opposite way.



Breeding isn’t a complicated thing. The couple is formed rather easily by random match, that’s why you can buy future breeders from different owners and they can be already adult fishes. This allows to avoid inbreeding.

In case if the fish couple doesn’t do well, it’s better to change a female. A united couple is rather preferable for breeding and keeping.

In the references it’s mentioned that spawning is stimulated by raising the water temperature and water renew. Actually it’s not required in the real life.

Provided with good conditions in a tank green terror spawns regularly. The problem is the opposite – how to decrease the frequency of spawning.

Chemical water parameters also don’t effect the situation a lot. Male and female choose a substrate good for breeding and start cleaning it. In the absence of the rock they like, the fishes can clean the bottom from the sand and lay the eggs right on the tank bottom glass.

Breeding color becomes more colorful. Blue splotches become fluorescence. Together with the bottom cleaning the fish also prepares some pits in the bottom where they will hide their ich fry later.

Fishes spawns usually in the evening or early in the morning. The female lays the eggs when moving over the rock surface and its trajectory looks like digit “8”. The male follows the female and fertilizes the eggs.

Usually there are about 200-300 egss in one breed, but if the female is large there can be about 1000 of them.

Healthy fertilized eggs have yellowish color and they are semi-transparent. Both parents take care of the eggs. The female waves over the eggs with her fins and the female guards the territory from strangers.

It becomes aggressive during the spawning period and attacks any moving object – fishes, net or hand.

However, sometimes it happens that parents don’t take care of their eggs or eat either the eggs or ich fry. The breed of such fishes should be incubated separately: carefully move the rock with eggs out of the tank and move it into an incubator – another small separate tank with the same water parameters.

The sprayer is put above the eggs. The eggs that became white should be removed with pincers and Sera Mycopur should be added into the water.

Eggs time of germination is 3-4 days, ich fry germination time is 2-4 days. After ich fry appears the female takes it into one of the pits in the tank bottom that were prepared in advance.

Juveniles are quite large and they have good appetite. Start feed for juveniles is the following: brine shrimp egss, microplankton or its artificial substitute, egg yolk among other things.