The Green Terror Andinoacara rivulatus (previously known as Aequidens rivulatus) is a most beautiful fish with an overall green and blue metallic sheen. In addition, they have a magnificent array colors that can be purple, pink, red and/or electric blue. The males are the most colorful of this species and develop a brilliant red edging on their tail fin, but the the females are also quite striking. They are also known as the Orange Saum, Gold Saum, amd White Saum.
These Cichlids is similar to its close cousin, Andinoacara stalsbergi, which is also called a Green Terror. In fact, A. stalsbergi was previously included in A. rivulatus until 2009, when it was described as it's own species. Although the Green Terror, A. rivulatus, grows slightly larger, the best way to determine the difference between the two fish is in the coloring of the scales and fin edging. On A. rivulatus, the scales have a lighter blue to green edge with a dark center, and their dorsal and caudal fins have a thick orange or white edging. The scales of A. stalsbergi are reversed, with a dark blue to green center and a dark edging, and the fins have a thin white edging.
This species also tends to be confused with its very similar looking relative, the Blue Acara Aequidens pulcher. For a time it was actually known as the A. pulcher, but is now recognized as an independent species. Though they look very similar in many aspects, there are some key differences between these two fish.
In color the Blue Acara is mostly a steel blue-gray, with less of the green sheen seen on the Green Terror. The Green Terror is larger, reaching up to about 10 - 12" (25 - 31 cm) in length in the wild, while the slightly smaller Blue Acara only gets to be about 8 inches (20 cm). A mature Green Terror develops a more pronounced hump on its head while the Blue Acara retains a more sloped forehead. In addition, the Green Terrors are also significantly aggressive than the Blue Acara (one of the reasons for the name "Terror").
This cichlid is a hardy fish that is moderately easy to care for. It's a rewarding specimen for the more experienced aquarist to keep as long as the water quality is maintained and they are provided a high quality diet. They are a ready feeder and if bred they become excellent parents, though they are known to sometimes be a bit lax with their first clutch of eggs.
As is typical with most large cichlids, the Green Terror is aggressive and requires a large aquarium. When young they can readily be kept in a community tank with other South American cichlids, but as they mature the become very belligerent and should be seperated into their own tank or into a tank with similarly sized and aggressive tank mates. They need at least 30 to 40 gallons of space just for themselves when kept as a single fish. As a pair they will need at least 75 gallons or more so as not be so aggressive, and even larger if kept with other large similarly aggressive tankmates.
The aquarium water should be neutral to slightly acidic, a little on the softer side, and have a moderate amount of current. They are fine with normal lighting and a gravel substrate. Provide lots of rockwork with caves and hiding places but be sure to leave an open area for swimming. Sunken driftwood can be used not only as a decoration but also as a water conditionting agent to help keep pH down in a too neutral aquarium.
Sex
Green terror cichlid 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 green terror female feature is that as a rule she is more aggressive then the male, especially during spawning period. Usually, all other cichlid fishes act the opposite way.
Breeding
Breeding isn’t a complicated thing. The green terror cichlid 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 fish. A united fish couple is rather preferable for breeding and keeping. In the references it’s mentioned that green terror 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. Green terror cichlid 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.
Green terror fish 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 green terror fish 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. Green terror cichlid 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.
Credit :
https://meethepet.com/green-terror-aequidens-rivulatus/
http://animal-world.com/encyclo/fresh/cichlid/GreenTerror.php
https://aquariumtidings.com/green-terror-complete-care-guide/
https://en.aqua-fish.net/articles/guide-keeping-breeding-green-terror-cichlids