A guide on keeping Green Terror Cichlids
The Green Terror is an enormously popular fish with many cichlid keepers due to it's great colouration and looks but unfortunately it does have a bad reputation for being overly aggressive towards other tank mates compared to other cichlids, in some cases this can be due to individual specimens that have an aggressive trait but there are also cases where the aggression can be a result of the fish not being housed correctly so hopefully this article will help to deal with such problems and help you to keep these fish in the correct environment and keep them healthy on a long term basis.
Origin, size and classification
So where do this fish originate from, looking at the overall shape of the Green Terror it is no surprise that their natural habitat is South America where they can be found from Peru to Ecuador, they do closely resemble the Blue Acara as juveniles and on many occasions have been mistakenly placed in the aquarium as Acaras but as they mature it soon becomes obvious that they are not the same fish. The Green Terror can reach an adult size of 30 cm (12 inches), this is larger than the adult size of the Blue Acara and the Green Terror will display a greener tinge to their body colouration compared to the Acara. Their Latin name is Aequidens rivulatus and like many cichlids the males will develop pronounced foreheads, small nuchal humps can become quite prominent as the adults reach maturity and display to the females. Mistakes can be made as juveniles as the younger fish may display a bluer colouration which will change over time.
The scales of the Green terror can take on a sparkling appearance as they reflect the light and the colours can seem to change from a plain green to a bluish green colouration as the light hits the scales in different directions. The underbelly can have a pink or brown colouration and they will display patterning on their cheeks while also possessing lateral lines running the length of the body.
As mentioned above adult specimens can grow quite large so ensure that your aquarium is large enough to cope with this, fuller aquarium details will be covered in later sections of this article. Tank mates will need to be chosen carefully, do not keep these fish with peaceful species or skittish species as the Green Terror will stress these fish to the point of on-setting diseases etc. in the tank.
Setting up an aquarium for the Green Terror Cichlid
As expected most aquatic stores sell Green Terror specimens as juveniles, they will probably only be a couple of inches in length but as mentioned above they do grow in size, adult males can reach a length of 8-10 inches with the females being slightly smaller so when planning which aquarium to place them in this must be taken into consideration. Juvenile specimens can be kept in an aquarium that holds approximately 50 Imperial gallons (roughly 230 litres) of water but when adult they will require at least 100 Imperial gallons (approx. 455 litres) of water to be housed in correctly. They do need swimming space, make sure the aquarium is at least 48 inches (122 cm) in length (60 inches - 152 cm - is preferable) and the depth should allow the fish to turn with ease. The choice of substrate is not critical but make sure that any gravel uses is well rounded without any sharp edges as they are constant diggers and sharp edges will lead to injuries. The problem with the digging is that they will uproot plants but at the same time plants provide excellent cover for the Green Terror so the use of synthetic foliage may be the solution unless any live plants are weighted down. Add rocks or wood to the aquarium but make sure that it is placed before the substrate to prevent these toppling onto the fish if they excavate underneath.
Like all of the larger cichlids, the Green Terror is classed as a high waste producer so the filtration must be capable of dealing with the high bio-load that the waste will add to the aquarium. An external/canister filter will be required for this task and the tank should be fully cycled before adding the fish. Regular water changes will also need to be performed, at least 10% weekly, if the nitrates start to increase then increase the size of the water change accordingly until they settle to an acceptable level.
Green Terrors do not require high water temperatures, they are quite happy within a range of 20-24 °C (69-75 °F) but I would try to keep the temperature at the higher end of the range. They can tolerate a fairly wide range of pH levels compared to some species of fish but do not let the pH reach extreme levels or it will affect their general health. A range of 6.5-7.5 pH is perfectly fine.
The Green Terror can be housed by itself without any problems but if you do wish to keep these with other tank mates then choose the other inhabitants carefully. Only add fish that can handle themselves and they should be of a similar size to the Green Terror that you are going to add. Similar sized cichlids make good tank mates but do not overcrowd the aquarium, each fish will need its own territory so the careful placement of décor will help with this, adding the Green Terror to the aquarium after the other inhabitants may also help to keep the aggression down as it will not have had the chance to set up it's own territory before the other fish. I would also recommend keeping a single specimen of the Green Terror if there are other fish in the tank, a male and female together will cause enormous aggression problems of they decide to breed in the future.
Sexing and breeding the Green Terror Cichlid
Sexing the Green Terror is not too complicated if you have a small amount of experience with these fish but even some experienced keepers can get their sexing results wrong, here are a couple of pointers to give you some idea of which sex of fish you have. As mentioned above males tend to grow larger than the females when fully matured, however as most keepers purchase these fish as juveniles this tip does not come into play.
The more common signs are as the males mature their finnage becomes extended particularly with the dorsal fin, they tend to display a brighter colouration compared to the females and some mature males will develop a small nuchal hump on their foreheads. Females do look duller than the males but the only true way to get a breeding pair is to purchase a small group of juveniles, allow them to grow on and let them pair off naturally.
Green Terror cichlids are egg depositors and once they learn to be good parents they will tend their eggs and care for the young fish. Flat rocks will provide spawning sites for the female to lay her eggs on which the parent fish will clean first before the eggs are actually laid. Raise the temperature of the water by a couple of degrees to induce spawning but do not expect results with the first few batches, they will become good parents in time so patience is the key here.
The female tends to care fore the eggs once laid while the male will coast around the spawning site to prevent any fish from posing a threat to their brood. The eggs should hatch after 3-4 days but any eggs that remain white are either unfertilised or have developed a fungus, these eggs are useless and should be removed from the aquarium.
Once the fry have hatched they will eat their yolk sacs initially so food does not b e provided for them until they become free swimming, at this stage it may be wise to remove the parent fish and raise the young yourself. Keep the water quality as high as possible as the fry are very sensitive, regular water changes must be performed and any uneaten food must be removed from the aquarium before it spoils the water quality. The fry can be fed on newly hatched brine shrimp or crushed flake for variety and remember that they only have small stomachs so feed them small amounts at a time but also make sure that they get fed 3-4 times per day.
The growth of the fry may be slow initially but once the growth takes them to just under an inch in size, their appetite may increase and growth will increase at a faster rate. When the juveniles reach a size of 1.5 - 2 inches they can be moved onto other aquariums or passed onto other keepers.
Although it is agreed that the Green Terror cichlid accepts a wide range of water parameters this does not mean that they will also accept a drop in water quality, always test the water and make sure that the quality is kept high.
If you do not have the means to move on the young Green Terrors then think twice about attempting to breed these fish, overcrowding in the aquarium will lead to aggression problems, it is far better to keep these fish in spaces that allows them to have their own territory.