Green Terror Cichlid (Aequidens Rivulatus) | Ultimate Care Guide

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The Green Terror Cichlid (Aequidens Rivulatus) is a freshwater fish that is native to the tropical river basins of Peru and Ecuador in South America. The coastal slopes of the Pacific Ocean are home to the fish, from the Esmeralda River in Ecuador to the Thumbes River in Peru.

The Green Terror’s name originated from Latin, Rivulus, which means a stream or streaming, and adequately describes the turquoise, wave-shaped dashes and spots on the fish head and gill covers.

The Green Terror Cichlid is large fish that belongs to the largest order of fish, Perciformes. They have pointed dorsal fins and magnificent metallic blue and green colors.

Green Terror Cichlids are also known as Gold or White Saum. Other common names include Green Terror, Green Terror Fish, Green Cichlid, Terror Fish, Rivulatus Cichlid, and Terror Cichlid. It is referred to as the Vieja Fish in Peru and Ecuador.

Ironically, the Green Terror Cichlid is not a green fish. The males have a bright blue and green metallic color, complemented with an orange line outlining the tail fin and on the tip of the dorsal fin. Females are darker and smaller and have a less-pronounced or absent striped-orange pattern on the caudal and dorsal fins. They also have pink, red, and electric blue colors. The face has patterns of stripes and spots of blue and green color.

The juvenile fish have a distinct appearance with more silvery-blue shading than adults. As they get older, their color deepens to a metallic green color.

It is easy to distinguish between males and females as the adult male develops a round hump on its head. This hump is made of fatty tissue and only appears during the breeding season when in the wild, but while in aquariums it can be permanent. Males are also larger than females, and they have an elongated dorsal and pectoral fin. The stripe pattern on their face is more consistent. The male has a blue anal fin, and the female has a green anal fin.

As a general rule, Green Terror Cichlid grow up to 12 inches in the wild and about 8 inches in an aquarium.

The average lifespan for a Green Terror Cichlid is 7-10 years.

Green Terror Cichlid (Aequidens Rivulatus)
Green Terror Cichlid (Aequidens Rivulatus)

Green Terror Cichlid Care

The natural habitat for the Green Terror Cichlid is fresh water in tropical climates, away from the salty water of estuaries and river mouths. These bodies of water are usually sandy, and they are often shady, with plenty of places to hide in the shade.

The ideal habitat for Green Terror Cichlid is a minimum 35-gallon tank for a single fish or a 75-gallon tank for a pair. They need plenty of room to swim as they are active swimmers and will explore the entire tank. A larger tank size can also help control aggressive behavior.

The suitable water temperature for a Green Terror Cichlid is between 68-77°F with neutral pH (6.5-8.0), and water hardness should be between 5-20 dGH. Although not sensitive to light, it will hide from bright light, so the tank should be moderately lit.

Green Terror Cichlids are tropical freshwater fish, so they will enjoy plants and rock formations. For the freshwater tank, large rocks, driftwood, and sand are the perfect substrate. They can act as a natural barrier when in a community tank. Avoid rooted vegetation because this fish is a digger and will uproot plants. Floating plants like Anubias or Java Fern may be better options. A large flat rock should also be placed in the corner of the tank and may be used for spawning. Any plants should be anchored with large stones also, as the fish will rearrange items in the tank continuously otherwise. Plentiful rockwork that provides caves and hiding spots is ideal for their tank.

To maintain optimal water parameters, use an external filter to control water chemistry. Driftwood will also help bring down the pH. Change 15-20% of the water every couple of weeks.

A good indicator for the condition of your tank is if the adult male’s colors fade. This is a signal that something is wrong with your water.

The Green Terror Cichlid is an omnivore, which means it is an opportunistic fish. In the wild, they are carnivores and feed on worms, crustaceans, and insects.

In the home aquarium, you can feed them pellets. For variety, you can supplement with frozen and live food. Shrimp, earthworms, and krill are all good choices to feed them, as are crickets, fish fillets, and tube worms, plankton, and green vegetables. Larger fish require larger pellets and flakes and live food. Live red earthworms will give them the best coloring.

Large adults have large mouths, and food size should be appropriate. Food that stays on the water surface and resembles the food they eat in the wild is ideal. A well-balanced diet will boost their natural coloring, power, and immunity.

The Green Terror Cichlid should be fed twice per day, three times per day when young. If they demonstrate prey drive or aggression, this may be a sign they are hungry. They will overeat if given the opportunity, so don’t overdo their feeding.

Green Terror Cichlid Breeding                  

Breeding can take place in good water conditions, but warmer and slightly acidic water with a pH of 6.5 will help the couple spawn.

The fish will clean their site before breeding. This may be a flat rock or the bottom of the tank, on the tank glass.

For a compatible pair, breeding is relatively straightforward. Because the males are protective and will kill other fish, it is best to keep the pair alone while spawning.

Spawning usually happens in the evening or early morning. The female moves over the rock surface and lays the eggs in a figure-8 pattern. The male comes behind her and fertilizes the eggs.

The female may lay 400-600 eggs. Healthy fertilized eggs are yellow in color and are semi-transparent. The female waves over the eggs using her fins, and the male guards and protects her and the site. The eggs hatch in 3-4 days. The fry can be kept with the parents, who are very good with them. They will swim after 10 days.


Green Terrors belong to the Cichlid family and are prone to aggressive behavior. Additionally, because of its size, it can be very aggressive towards other fish especially during spawning seasons. Females can be more aggressive than males, and older fish are more aggressive and territorial. Their temperament may improve during the  reproductive stage, but they become violent and aggressive during spawning season.

They are curious and will likely spend time exploring the tank. They are benthopelagic fish and will swim all over the tank, reaching the surface for food and exploring every crack and crevice.

Tank Mates for Green Terror Cichlid

Despite their tendencies toward aggression, Green Terror Cichlids can do well in tanks with similar-sized fish. They do not pair well with smaller fish because they are likely to kill them or eat them. This fish is also better suited alone or as a mated pair. Fish with similar temperaments can make good tank mates as they will not be able to be bullied.

Good tankmates for the Green Terror Cichlid include Jack Dempseys, Managuense Cichlids, Firemouths, and Flowerhorns, Bleeding Heart Tetras, Gars, Silver Dollars, and medium-to-large catfish. They also pair well with Oscars and Blood Parrot species.

Smaller fish like Corydoras and African Cichlids will likely be killed. In addition, the spine of the Corydoras can penetrate the Cichlid’s mouth and can cause its death.

Red Terror and Green Terror cichlids share the same temperament and make good tank companions, whereas the Green Terror will bully the Blue Acara, which is a less aggressive fish.

A Tiger Barb, on the other hand, is a poor tankmate at only 2-3 inches as an adult. Its small size makes it impossible to keep it safely with an adult Green Terror.

Green Terrors and Clown Loaches share similar sizes, reducing the risk of being eaten by each other. They also have similar acidic water preferences, so they are ideal tank mates.


Green Terror Cichlids are susceptible to many infections, including parasitic infections, ich, skin problems and HLLE, or Head and Lateral Line Erosion, or Hole-In-Head disease. With a strict clean-water routine, illnesses can be avoided.

With HLLE, the fish’s flesh can deteriorate, and holes can run through the head and body. It is typically caused by poor water conditions due to high hardness levels.

They also have a predisposition to lymphocystis disease, which is a viral disease that is common in tropical fish and infects the connective tissue cells of the fish. Characterized by white granular lesions that appear on the skin and fins and sometimes on their mouth and gills, stress is usually the instigating factor, usually from low oxygen levels and bad pH levels.

Ich can be treated by increasing the water temperature to 86 degrees Fahrenheit for three days. If this does not cure the Ich, the fish can be treated with copper, making sure copper levels are proper.

They are also prone to skin flukes, protozoa, worms, and fungal and bacterial infections. It is important to know the signs of these conditions so they can be caught and treated early. Be cautious when adding new items to your tank as they can have bacteria and can bring disease to your tank. Make sure you clean and quarantine everything being added to an established tank.

Where to Find Green Terror Cichlid for Sale

In general, you can buy Green Terror Cichlid online or in stores. The juvenile fish is affordable, but the fish become more expensive as they mature. Prices range from $18.99 to $85.99.