Over time I have seen the Oscar Cichlid be the topic of discussion in numerous threads. I can see why as this is a beautiful fish with a lot of intellegence and personality but this has prompted me to attempt to write an informative fact sheet pertaining to Oscars, thier care, and origins for the newcomers of this hobby and people new to the Oscar.
Oscar Cichlid (Common), Marbled Cichlid (very uncommon), and Velvet Cichlid (also uncommon)
South American Cichlid
Acara compressus, Acara hyposticta, Astronotus ocellatus zebra, and Astronotus orbiculatus
This fish is native to South America and can be found in Peru, Ecuador, Colombia, Brazil, and French Guiana, and occurs in the Amazon river basin, along the Amazonas, Içá, Negro, Solimões, and Ucayali river systems, and also in the Approuague and Oyapock drainages. Due to fish releases from the pet trade they have also been found in China, Austrailia, and in some areas in Florida.
Oscars have been reported to grow to about 16" in length and up to 3.5 lb in weight. The wild-caught forms of the species are typically darkly coloured with orange-ringed spots or ocelli on the caudal peduncle and on the dorsal fin.These ocelli have been suggested to function to limit fin-nipping by piranha which co-occur with Oscars in its natural environment.The species is also able to rapidly alter its colouration, a trait which indicates territorial and aggression behaviours amongst conspecifics. Juvenile oscars have a different colouration from adults, and are striped with white and orange wavy bands and have spotted heads. In the pet trade these fish are ususally very brightly colored with red or gold along it's sides.
Captive oscars may be fed high quality fish food designed for large carnivorous fish. I recommend Hichari Cichlid Gold and Cichlid Staple pellets. Don't be afraid to supplement with tropical flakes and other treats as well.
They even eat crayfish, worms, and insects (such as flies or grasshoppers). Crickets are also good live food. I do not suggest feeding live foods more than once per week though as it can lead to higher aggression and various vitamin defeciencies, live food may increase the rate of growth but also may cause endoparasites. Since these fish eat fruit in the wild, it can also be used as a type of food. Just about anything that fell into the water would be eaten by oscars. Live feeder fish can be given, but fish such as goldfish
and rosy red feeder minnows should not be fed. They also contain an enzyme within their flesh which binds vitamin B1, leading to deficiency and in rare cases have been known to cause bowel obstructions leading to death.
1.Tiger Oscar fish - this most resembles the original Wild Oscar fish and is extremely common
2.Albino Tiger Oscar fish - if you want to be pedantic then this is actually a Lutino Oscar fish as it exhibits colour pigmentation, whereas true albino creatures do not. However, for the sake of stopping confusion, they are normally referred to as albino.
3.Red Oscar fish - first bred over 40 years ago, the red Oscar fish is truly beautiful when displaying its vibrant red colouration
4.Veil Tail Oscar fish - these Oscars have been bred to exhibit long fins. Nevertheless they are beautiful fish with their long flowing fins that often look like silk
5.Red Lutino Oscar fish - this is what we would call a red Lutino Oscar fish, although some people may still referred to it as albino, does it really matter?
6.Golden Oscar fish - This Oscar is very simular to either the Red Oscar, or the Tiger Oscar but born or bred lacking the red gene leaving it with striking golden coloration. This color form is very rare and can be desirable.
Ok folks these fish are not guppys, they can get 16" and up to 3.5 lbs. This is also a fish with a very large bio load meaning a lot of waterchanges. I recommend a heavily filtered 75g tank for Oscars, although they can be kept in a 55. I have found that the 55g tanks are simply too narrow for the oscar to be able to turn around in. Also you must be dedicated to doing waterchanges often, meaning in some cases once per week. Temperatures are best kept at 80-85F in my experiance, and they do not do well in sub-tropical (below 78F) temperatures. Oscars like acidic water with a pH level around 6.5 to 7.0. However, they will be okay with levels up to 8.0. However, pH level of 7.0 is ideal.
This topic is pretty widely disputed but two facts remain. You never mix African Cichlids with South American Cichlids, and that Oscars will eat whatever will fit into thier enormous mouth. To be honest you would do best to have just your Oscars in the tank alone, but if you are dead set on having some 'company' for them then avoid catfish as the oscars get bigger as they have spines that will get lodged in the oscars throat, and try to find something that is peaceful but very fast.
Plain and simple, as oscars mature the begin to hate plants. This means when the fish gets to be around 6-8 inches they will rip up and destroy any plant you put in the tank. Your best choice of decor is stone and drift wood, many great looking tanks can be built with just stone and driftwood. Also be prepared, this fish has a mind of its own and is very intellegent meaning that he will rearrange the tank to how he wants it.
Oscars are what we call monomorphic. This means that males and females look the same. Unfortunately, you won't be able to go into a shop and choose a male and a female like you can with other species of fish such as guppies. You will normally only know the sex of your Oscars when they start laying eggs. There are various ways you can increase your chances of obtaining a male and a female. Probably the easiest way is to find somebody who is willing to let you have a known mating pair of Oscars. Most people would prefer to get their Oscars at a young age so the best way to make sure you get a pair is to buy several Oscars at a very young age and wait for them to pair off. Obviously, the more you get, the more chances are that you will have a pair. The downside of doing this is that you have to make sure there is someone who will take the Oscars you are left with when you have finally got your pair. Only when Oscars start laying eggs will you know for sure that you have got a male and a female. The females egg tube is overall in the shape, not unlike the pointed end of an egg. The males sexual organ is pointed and looks rather like a thorn.
The Oscar can live up to 15 years in the proper conditions, but be prepared as the oldest I have heard of lived to 21 years in captivity.
Oscars are one of the fastest growing fish you'll come across. You will often buy baby Oscars between an inch and 2 inches. These little guys will easily gain 1 inch a month for the first seven or eight months of their life. Not all Oscars grow at the same rate, some grow faster and bigger than others. Tank size, water quality and food will all play a part in an Oscars growth. Expect the average Oscar to be seven or 8 inches by the time it reaches 12 months old
Left to their own devices, Oscars will happily breed without any help from anyone. Many people have successfully bred Oscars in captivity and virtually every Oscar sold in fish stores have been bred in captivity by fish breeders. The difficult part of breeding Oscars is obtaining a male and female that will pair up and produce fertile eggs. However, entering purposely into a breeding venture must be thought through very carefully. I wouldn't recommend doing it just for the fun of it. If you are successful, you may end up with lots of fish that you can't do anything with. A mature pair of Oscars can produce up to 1000 eggs which can all hatch. Oscars will not pair off until they become sexually mature at around a year-18 months old so you will have a long wait if you buy them as babies. Oscars prefer to lay their eggs on a flat surface, they will not lay their eggs directly on the substrate. If there is nothing in the tank for them to lay their eggs on, they will clear a patch of gravel/sand until the bottom of the tank is exposed and then they will lay their eggs there. If you want your Oscars to breed then you are probably wise to put something in the tank like a piece of flat slate or rock. They like to clean the surface of the rock vigorously before they lay their eggs. It's amazing how clean they will get the rock, there will be absolutely no sand or gravel left on it whilst they are going through this process of cleaning the rock. A pair of breeding Oscars will go through various rituals such as lip locking, also known as jaw locking, you may also notice them chasing each other around the tank, nipping at each other and performing what sometimes looks like a very rough behaviour. Your Oscars may perform all of these strange behaviours, or just a couple. It is quite rare, but sometimes they don't do any of them. if you do start seeing your Oscars performing these strange behaviours, don't get too excited, it can often be many months before they actually start laying eggs. A short time before they start laying eggs, one or maybe even two days, they will go off their food. You will have probably observed them acting strangely such as excavating the substrate, as in picking up mouthfuls of gravel/sand and moving it to another part of the tank. When all of the eggs have been laid, both the female and the male will hover over the eggs and fan them with his pectoral fins. This is to oxygenate them. They will also become very protective and aggressive. Any fish that dares to go near the eggs can expect a very hostel reception.The eggs normally take 3 days to hatch. If they are fertilised they should turn a lightish tan colour. If they stay white, they are not fertilised. You may notice the Oscars appear to eat the odd egg, this is exactly what they are doing. They know a bad egg and will remove it straightaway. Don't be surprised if you wake up in the morning and all the eggs have gone. This is very common and happens more often than not. Various things contribute to this happening such as eggs that are not fertilised or parents that have been spooked in some way. It is very common for fungus to grow on the eggs, this normally happens to unfertilized eggs. If you have a mixture of unfertilized and fertilized eggs then the Oscars should remove them. If there are lots of dead eggs amongst fertilized eggs than the fungus may attack the good eggs.
Although oscars are very hardy fish, treating them with salt is not recommended. The areas they come from are freshwater and they have thousands of years of evolution against them. I don't like to use meds but if you have to store bought meds should suffice.
Oscar Prone Illness
There are a few things Oscars are prone to catching, here I will list them and the common cures.
Symptoms: The first symptom of slimy, white mucous feces, even while still eating and acting normal. Further signs are the fish hiding in the corner it's head down, head above the eyes gets thin, they blacken in color, and swim backwards. Hexamita are intestinal flagellated protozoa that attack the lower intestine. discus
and other large cichlids, especially Oscars, are especially prone to Hexamita. As it is a disease of the digestive tract, a wasting away or loss of appetite may be experienced.An effective treatment is the drug metronidazole. This disease is often confused with another disease called Head and Lateral Line Erosion (HLLE), which use to be called "hole-in-the-head" disease, because both these diseases are often seen simultaneously in the same fish. Head and Lateral Line Erosion disease looks like cavities or pits on the head and face. It is not a protozoan disease, but is actually caused by environmental conditions.
Symptoms: Begins as small pits on the head and face, usually just above the eye. If untreated, these turn into large cavities and then the disease progresses along the lateral line. Head and Lateral Line Disease is also known as Hole-in-the-Head Disease, Lateral Line Erosion (LLE), and Lateral Line Disease (LLD). It is attributed to a nutritional deficiency of one or more of: Vitamin C, Vitamin D, calcium, and phosphorus. Though its cause is not definitively determined, it is thought to be caused by a poor diet or lack of variety, lack of partial water changes, or over filtration with chemical media such as activated carbon. Hole In the Head Guard made by Jungle is a very effective treatment when combined with vitamin supplements.
Ich, Ick, White Spot Disease (Ichthyophthirius multifiliis)
Symptoms: Salt-like specks on the body/fins. Excessive slime. Problems breathing (ich invades the gills), clamped fins, loss of appetite.
Ich, Ick, or White Spot Disease is the most common malady experienced in the home aquarium. Luckily, this disease is also easily cured if caught in time! Ich is actually a protozoa called Ichthyophthirius multifiliis. There are three phases to the life cycle of this protozoa. Normally, to the amateur aquarist, the life cycle is of no importance. However, since Ich is susceptible to treatment at only one stage of the life cycle, an awareness of the life cycle is important.
•Adult phase - it is embedded in the skin or gills of the fish, causing irritation (with the fish showing signs of irritation) and the appearance of small white nodules. As the parasite grows it feeds on red blood cells and skin cells. After a few days it bores itself out of the fish and falls to the bottom of the aquarium.
•Cyst phase - after falling to the bottom, the adult parasite forms into a cyst with rapid cell divisions occurring.
•Free swimming phase - after the cyst phase, about 1000 free swimming young swim upwards looking for a host. If a host is not found within 2 to 3 days, the parasite dies. Once a host is found the whole cycle begins anew.
These three phases take about 4 weeks at 70° F but only 5 days at 80° F. For this reason it is recommended that the aquarium water be raised to about 80° for the duration of the treatment. If the fish can stand it, raise the temperature even higher up to 85°.
The free swimming phase is the best time to treat with chemicals. Raising the aquarium temperature to 80° F will greatly shorten the time for the free swimming phase to occur. The drug of choice is quinine hydrochloride at 30 mg per liter (1 in 30,000). Quinine sulphate can be used if the hydrochloride is not available. The water may cloud but this will disappear. By reducing the time (with raised temperature) of the phases, you should be able to attack the free swimming phase effectively.
Some aquarists like to use malachite green, but it tends to stain the plastic and silicone in the aquarium. Most commercial remedies contain malachite green and/or copper, which are both effective.
***I will update this thread as my research continues but if I left out anything that needs added please leave a comment***