Green Terror (Aequidens rivulatus) Small

The Green Terror is a gorgeous cichlid that belies its common name. They are relatively peaceful but can become very aggressive during spawning seasons. They’re known for becoming quite friendly with their keepers  Minimum tank size 130 litres, adult size: Males 25-30 cm, Females 18-20 cm.  Intermediate aquarists recommended do to sensitivity to water parameters.

Green Terror (Aequidens rivulatus) is native to South America. It inhabits the coastal slopes of the Pacific Ocean from the Esmeralda River in Ecuador to the Thumbes River in Peru. Colors change between juvenile and adult fish, with juveniles having more silvery blue shading than adults. Some people have long considered its relative, the Andinoacara stalsbergi, the true Green Terror as it has a greener coloration.

Behaviour They are relatively peaceful and known for becoming quite friendly with their keepers.  However, because of its size, they can be extremely aggressive towards other fish especially during spawning seasons. This species of Cichlid is very aggressive and territorial – females are often more aggressive than the males. The older the fish the more aggressive and territorial it becomes.  Also, it’s better to keep this fish as a single specimen or as a mated pair.

They will freely swim around the tank and look for food from the surface to the bottom part of the tank.

One of the biggest differences between males and females is their head. An adult male develops a round hump on its head. In nature, these humps only appear during the breeding seasons, while in aquariums they can be permanent.

Tank Conditions Even though this species is not sensitive to light, it hides away from bright light. Therefore the tank should be kept moderately lit with moderate currents.  Use large rocks, sand and driftwood as substrate. But avoid large gravel as it can cause digestive problems if eaten. Getting the correct tank setup is crucial to preventing unwanted behaviors.

Make sure to provide caves but also enough space for free swimming.  Rocks, wood and plants can act as a natural barrier when in community tanks and help stop bad behavior toward other fish. This fish likes to dig, and rooted plants will likely be pulled out and eaten. So consider floating plants such as Anubias or Java Fern that will be a better solution and they can also provide shade.

Green Terror Cichlids need a 130 litre aquarium if kept alone, or minimum 300 litres for a pair.  The more space you can give to this fish the better, as with spacious tanks its aggressive temperament decreases.

You should keep them as a single fish or as a mated pair. You can either purchase a formed pair or let them pair naturally.

Compatibility The Green Terror is generally peaceful with other fish of similar size and disposition, but does become more territorial as it matures. THey are best kept with fish of similar size and temperament. Bigger size fish are also a good choice.  The following fish make good tankmates:

• Other large Cichlids (such as Managuense Cichlids, Jack Dempseys, Fire Mouths and Flowerhorns)
• Large Characins (such as Bleeding Heart Tetras)
• Large Loricariids (such as Plecs and medium to large catfish)
• Gars
• Silver Dollars
• Pacus

They shouldn’t be kept with smaller fish such as Corydoras and African Cichlids because these smaller fish will likely be killed. Also, Corydoras can be deadly as their spines can penetrate the Cichlids mouth and eventually cause its death.

Feeding They have a voracious appetite and will eat almost anything placed into their tank. Although they prefer meaty foods, they will eat fresh, frozen, freeze dried, flakes or Cichlid pellets including house flies, small earthworms, small mysis shrimp, ghost shrimp, bloodworms, krill, tubifex, ocean plankton, brine shrimp, etc.  Larger pellets, flakes and live food are recommended for larger specimens. Occasionally, you can also feed them vegetables such as cooked peas and spinach.

It is important to not overfeed your Cichlids with high protein food to avoid digestive problems.

Care They are relatively easy to care for providing you can maintain the water conditions. They are very sensitive to deteriorating water quality, so nitrate and phosphorous levels must be kept in constant control. Hence, we advised the use of a bio-filter and or external filter. Also, change at least 15-20% of the water tank every couple of weeks.

Green Terror Cichlids are susceptible to many infections, parasites, skin problems and HLLE (Head and Lateral Line Erosion). Fish suffering from HLLE will develop pitted holes that usually start around the eye area and continue, forming a line towards the tail.

These illnesses can be avoided if you keep a strict clean water regiment. For example, HLLE happens when water hardiness is kept too high for a long period of time.

They are predisposed to the lymphocystis disease, a viral disease very common in tropical fish, infecting the connective tissue cells of the fish. Stress is a key factor in the development of this disease with white granular lesions appearing on the skin and fins and occasionally on their mouth and gills.

It is always best to avoid the use of chemicals when dealing with Cichlids but instead try to keep water clean and ensure a healthy environment with good oxygenation.

Colors are a good indicator of fish and tank conditions. Typically, adult fish have bright colors and if they start to fade, there is likely something wrong.