Green terror cichlid (Aequidens rivulatus)

Green terror cichlid (lat. Andinoacara rivulatus, syn. Aequidens rivulatus) is a very bright colored cichlid of the Cichlidae family. Despite its scary name, it has been a tank fish for many years. Further in the article, you’ll know about proper keeping, feeding, choosing tank mates for green terror cichlid.

Habitat in the wild

Andinoacara rivulatus was first described by Albert Karl Ludwig Gotthilf Günther 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 ocean water. Cichlid inhabits both quiet backwaters and flowing sections of rivers.

This kind is often mistaken for another very similar fish – Aequidens pulcher. There were 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.

Andinoacara rivulatus is a rather large fish, and in the wild, max size can be about 25-30 cm, when Aequidens pulcher max size is just about 20 cm in the wild. The reproductive male has a rather visible rounded hump on its head, whereas Aequidens pulcher male hump is rather less pronounced. Also, Andinoacara rivulatus is rather more aggressive than the Aequidens pulcher.

Description

It is a large and heavyset fish, and in the wild green terror cichlid, the max size is about 12 inches (30 cm). In a tank, the fish is usually smaller – about 8 inches (20 cm). 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 than females, and they have an 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.

Its specific name originated from Latin «rivulus» — a stream, and it is translated as «streaming,» meaning wave-shaped turquois dashes and spots on the fish head and gill covers.

As for the classification of this kind, it hasn’t been finally established yet.

For a long time, this kind was considered Aequidens kind, though it was obvious that fishes are not similar. Because of this, it became necessary to separate the fish as a standalone kind which happened in 2009.

Three geographically isolated morphs inhabit the West slope of the Andes in nearshore zones of rivers and streams. Andinoacara rivulatus with a greenish-yellow edging dwells in the Esmeraldas river basin flowing over North-West Ecuador and probably further to the North.

Andinoacara (Goldsaum) with orange or dark-yellow edging inhabits the West, South-West Ecuador, and North-West Peru. Andinoacara sp. «Silbersaum» ( stalsbergi) with silvery edging dwells in West Peru.

At that, true Andinoacara rivulatus is quite seldom encountered in captivity, while the other two morphs have been kept in amateurs tanks since 70s last century. Nowadays, in pet shops, you can mainly see «Goldsaum»

Difficulties in keeping

Although it is a very beautiful fish that attracts aquarists, it still can’t be recommended for beginners. Green terror is a large, aggressive fish, and to keep it in a tank, it has to be rather spacious.

The couple can terrorize its tank mates, and they should be of the same size and the same aggressive temper. Besides, the fish is rather sensitive to water parameters and their abrupt change. Due to these facts, fish can be recommended only to the aquarists experienced in keeping large cichlids.

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

Like many large cichlids, they are very smart. During the time, they learn to recognize their owner and let him touch them. Also, they are not timid, and when someone approaches the tank, they gather near the front wall and see who is there, and this feature allows observing them without risking scaring them.

Care and keeping in a tank

Care is rather easy since it isn’t a very demanding fish. But still, it’s recommended for experienced aquarists since the fish is demanding in terms of water parameters, and it requires qualitative food.

Scientific NameAndinoacara rivulatus, syn. Aequidens rivulatus
FamilyCichlidae
Common NamesGreen terror, green terror cichlid, green terror fish, green cichlid, terror fish, rivulatus cichlid, terror cichlid
Ease of keepingMedium
Lifespan10 years and more
Tank size66 gals (about 300 liters) and more
TemperamentAggressive
Tank typeCommunity of large fishes
DietOmnivorous
Temperature77-82°F (24-26°C)
pH6.5-8
Water hardness9–20 dGH
SizeUp to12 inches (30 cm)

Lifespan

Green terror cichlid lifespan is about 10 years, but we also have information that it lives longer.

Tank size

Just like all South America large cichlids, Andinoacara rivulatus requires a spacious tank with clean water. For a fish couple, a tank of 66 gals (about 300 liters) capacity is recommended. In case if there are some tank mates, the tank size should be larger correspondingly. Also, as it is always true for the large cichlid – this one is rather large and aggressive, it needs a spacious tank. While green terror fish is young, it can successfully grow with other cichlid fish, 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.

Water parameters

Green terror fish is sensitive to water parameters, and it’s better for them when the water isn’t hard (5 – 20 dGH) with neutral pH (6.5-8.0). Water temperature should be 77-82°F (24-26°C). They can stand short-term water temperature decrease up to 64°F (18°C), but we don’t recommend exposing them to such stress.

Tank setup: decorations and plants

The tank should be moderately lighted, and the tank design should be typical for large cichlids – rocks, snags, and gravel bottom. It’s better not to put plants in the tank since fishes tend to dig the tank bottom and change it according to their preferences.

Provided with proper tank decoration with plants and other decorative elements, it may look awesome with just one couple of fish in it. The interesting fish’s behavior more than outweighs their quantity.

Considering green terror cichlids’ passion for digging substrate, the latter should consist of small-sized round pebbles so they won’t get cut by sharp edges. Usually, gravel or large/average-sized pebble are used as a substrate.

Unlike other cichlids, these don’t include plants in their diet. However, they tend to dig them out, especially during the spawning period. Thus, you should select undemanding stiff-leaved plants with a strong root system. Plants of Echinodorus kind and some of Anubias kind will do for this.

After planting, they should be additionally fixed with large flat stones. You can put plants in containers this way, and you significantly decrease the chances of digging them out. Large stones and snags are obligatory decorative elements for a tank with cichlids. One of these flat stones in the tank corners may later be used as a substrate for spawning.

Such a tank interior with the decorated back wall has a maximally natural look. It is possible to use artificial plants. The main thing is that all tank decorations are reliably anchored. Because the fish is always not satisfied with the interior and continuously changes it.

Filtration

It’s obligatory to use a powerful canister filter and to control nitrates and ammonia levels in the water. It will allow not only to collect various suspended matters from the tank water but also to avoid a high concentration of toxic substances of nitrogen metabolism in the tank due to the life-sustaining activity of useful nitrifying bacterias.

Feeding

Andinoacara rivulatus diet in the wild mainly consists of insects and their larva, worms, and other spineless species. In general, the fish isn’t demanding, and in the tank conditions, they eagerly eat all types of food, both live, frozen, and artificial. Many aquarists feed adult green terror fishes with non-fatty sea fish and prawns.

To select the food properly, you should keep in mind that green terrors are predators, and they require significant protein components in their diet. The food size also must be proper since large adult species have quite a large mouth.

Quality dry food for cichlids is a good choice in this case. Food made as large floating sticks is best for adult species. They stay on the water surface for a long time, and their shape resembles the food the fish eats in the wild. Well-balanced food boosts their natural coloring, vital power, and immunity. It’s better to feed juveniles with flakes or small pellets.

You should feed them several times a day. Hungry fish may demonstrate prey drive and attack their tank mates.

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. Green terror cichlid is a rather battlesome fish that 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 the green terror family – it is recommended to keep one fish couple in a tank to avoid fights. Often female is more aggressive than the male, and she is sometimes kept separate 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 and with angelfish since the latter will either be killed or stressed all the time. It’s better to use the following fishes as green terror cichlid tank mates: oscar, jack dempsey, arowana, convict cichlid, flowerhorn, blood parrot, jaguar cichlid, texas cichlid. You can keep it with some large catfishes, for example, sailfin pleco or suckermouth catfish.

First of all, all fishes sharing a tank with terror cichlid should be of similar size. Any small-sized species (even average-sized ones) will be eaten sooner or later. In a perfect world, if green terrors and their tank mates live in a community tank since they are juveniles and grow together, this will ensure a decrease in their aggression.

The tank must have many various shelters for its dwellers, and its volume should be enough for large fishes to live.

During their spawning period, they become aggressive towards their tank mates. If a male or a female started to prepare a nest for laying eggs, anyone who approaches it would be immediately attacked.

Gender differences: male vs female

Male and female don’t have many differences. The male has an orange stripe on its fluke. It’s larger and 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 than the male, especially during the spawning period. Usually, all other cichlid fishes act the opposite way.

Breeding

Breeding isn’t a complicated thing. The couple is formed rather easily by random matches, that’s why you can buy future breeders from different owners, and they can be already adult fishes. This allows avoiding inbreeding. If the fish couple doesn’t do well, it’s better to change a female fish. A united fish couple is preferable for breeding and keeping.

The references mentioned that green terror spawning is stimulated by raising the water temperature and water renewal. Actually, it’s not required in real life. Provided with good conditions in a tank fishes spawns regularly. The problem is the opposite – how to decrease the frequency of spawning.

Chemical water parameters also don’t affect 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. Along with the bottom cleaning, the fish also prepares some pits in the bottom where they will hide their ich fry later.

It usually spawns 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 eggs in one clutch, but if the female is large, there can be about 1000 of them.

Healthy fertilized eggs have a yellowish color, and they are semi-transparent. Both parents take care of the eggs. The female fish 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 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. The time of the egg germination is 3-4 days, and 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 they prepared in advance. Juveniles are quite large, and they have a good appetite. Start food for juveniles is brine shrimp nauplii, mycoplankton or its artificial substitute, egg yolk, etc.