Mascot: Fish
Family: Cichlids (Cichlidae)
Group: Perciformes
Origin: South America
Size: 25 to 35 cm.
DESCRIPTION OF THE OSCAR FISH:
Astronotus ocellatus, commonly known as Oscar, is from the cichlid family (cichlidae).
It is endemic to South America, therefore it does not exist naturally anywhere else.
It lives in the tributaries of the Amazon basin, the Negro River and Paraguay.
Its natural habitat is rocky areas with a fine gravel bottom, located in clean and warm waters.
Some populations have been introduced in the United States (Florida), China and Australia, for the market and aquaculture.
The Oscar fish, astronotus ocellatus, is a fish of the cichlid family, of which there is only another variety, astronotus crassipinnis.
It is often known by other common names, such as velvet cichlid, red oscar, tiger oscar fish or marble cichlid.
It is a very original fish, which changes its appearance as it ages, being very attractive in its juvenile state, with yellow and light brown colors, while when they age they are less showy.
They are easy to breed in captivity, provided they have enough space and are well fed.
They respond to the pampering that their owners lavish on them, being sensitive and also demanding, as if they were part of the family nucleus.
It is a good size fish, it can measure up to 35 centimeters.
They are oval in shape and fairly flat, with rounded fins, slightly bulging eyes, a large mouth, and strong jaws.
Not in vain, it eats everything that moves inside the aquarium that is smaller than it.
In the natural state, the oscar fish is usually dark, with orange ringed spots on the caudal peduncle and dorsal fin.
In captivity their coloration is “cryptic”, it is composed of irregularly arranged spots and stripes, which in young specimens are typically black, with white or orange stripes, with dots on their heads.
The colorations of captive-bred oscar fish are very varied, going through marbled colors, speckled, spotted, with red, black, all red or all black.
Its coloration, can also be changed, when it becomes territorial.
There are no morphological differences between the male and the female, although some scholars argue that the male grows faster than the female, and that in some natural populations (difficult to appreciate in an aquarium), the males have black spots at the base of their legs. your spine.
The Oscar is one of the largest American species, being able to reach up to 35 cm. and 1.6kg.
It is oval and rather flat, with long, rounded fins.
It has bulging eyes and a large mouth with strong jaws.
In its wild form it is usually dark in color (greyish green, black or striped) with orange or yellow ringed spots, although there are also albino specimens. Following some territorial and combat rituals, it sometimes changes color.
The name ocellatus is due to the ocellus that it has next to the caudal fin (the one used by fish to propel themselves).
The ocellus is a round spot, similar to an eye, with which they deceive predators.
DISTRIBUTION AND HABITAT:
The astronotus ocellatus, is a fish native to the Amazon region, being present in Colombia, Venezuela, Bolivia, Ecuador, Peru, Brazil, French Guiana, Paraguay, Uruguay and Argentina.
With such a wide geographical distribution, it is not uncommon for it to have been found in numerous river systems, with different habitats.
The favorites are shallow and calm waters, with white and silty waters, where they are usually found near tree roots or under plant covers.
BEHAVIOR AND COMPATIBILITY:
The oscar fish is intelligent and docile, it can even accept our caresses or eat from its owner's hand.
It is quite peaceful but very territorial, and can be aggressive with its partners in the reproductive period.
The oscar fish is not aggressive, however, its size and voracity prevent it from sharing an aquarium with other smaller fish.
You can look for other cichlids of similar size, with which to share space, although this requires having a large aquarium.
Fish compatible with the Oscar fish:
- Common Pleco fish, as long as it doesn't fit in the Oscar's mouth.
- Striped Rafaelo fish.
- Pleco Galaxy:
The following varieties of fish can coexist under restrictions, such as knowing each other since childhood:
- Flowerhorn.
- Green Terror Fish
Jack Dempsey fish. - King Midas fish.
- Pangasius shark, if they are of similar size.
- Koi Carp, if they are similar in size.
There are others that could coexist, depending on Oscar's personality, such as the Ancistrus, the Apple Snail or the Red Piranha.
REPRODUCTION OF THE OSCAR FISH:
Astronotus reaches sexual maturity after about a year, when it reaches 12 cm.
As a nest it uses a flat rock, which it previously cleans with its partner.
The female oscar can lay 300 to 2,000 eggs, depending on her maturity.
They are then fertilized by the male. They are normally oval and brown or beige, although after a few hours they become transparent.
Three or four days after laying the young are born, but they will need another five to develop.
For breeding, an oscar couple needs a space of at least 300 l.
When the fry are born, they will cling to the bottom and to the glass of the aquarium, using suction cups that they have on their heads.
First you have to feed them with artemia nauplii, but after a week they can feed on larvae or cut worms (tubifex).
After a month they must be removed from the aquarium, since the parents disregard it.
AQUARIUM CONDITIONS:
The oscar fish needs a good aquarium, which has at least 200/300 liters of water, in which the temperature is maintained between 20º and 28ºC.
The pH must be maintained in a range of 6 to 7.5, with a hardness between 90 and 357 ppm.
They need well-oxygenated water, but don't like too much water movement, so it's a good idea to put a couple of oxygen inlets in the tank.
They are fish with a tendency to dig into the substrate, which should be soft and sandy, with some rocks, roots and large wooden branches floating, to give it a more natural look, and provide them with places to hide.
It is recommended to make weekly water changes, in which between 30% and 50% of the aquarium volume is changed.
Another important detail, the aquarium water heater, it is convenient to place it outside, since it is known that some fish have broken the heaters.
- Temperature: 22 to 30ºC
- pH: 6 to 7.5
- dGH: 5 to 20º
Due to its large size, this fish needs a large space, from about 120 to 200 liters per specimen.
It is advisable to decorate the aquarium with logs and large, well-settled rocks, so that they cannot be dragged since they are very active and constantly dig.
The temperature should be warm, between 22 and 30 degrees, with a pH range between 6 and 7.5.
Cichlids are very dirty so you will need a very powerful filter and frequent water changes.
OSCAR FISH NUTRITION:
It is carnivorous, in its natural environment it feeds on insects (aquatic and terrestrial) as well as fish and crustaceans.
At the domestic level, it can feed on worms, insects, small or frozen fish, such as shrimp and hake.
It is an omnivorous fish in the broadest sense of the word, it will eat almost anything you put in the aquarium.
If there are smaller fish, it eats them.
Insects, crustaceans, zooplankton, all kinds of vegetables…although it seems that what he likes the most are meaty foods, with fruits and other vegetable materials as the preferred option.
It must be provided with a high protein diet, in which a cichlid pill must be the fundamental part and complement it, with live or frozen food, worms, shrimp, river shrimp, crickets.
With these fish there is a danger of overfeeding, because they are very smart and learn to ask their owners for food every time they see them approach the aquarium.
REPRODUCTION:
The reproduction of the oscar fish is relatively simple, since they are exceptionally prolific, a couple can lay up to 1,000 eggs.
To find a breeding pair, you must start with a group of at least six young fish, which upon reaching sexual maturity will mate naturally.
The aquarium should have flat rocks or similar structures, which provide them with a good number of places to spawn.
During courtship, the pair will select and clean the site where spawning will occur.
The eggs are white and opaque after laying.
Those that are viable will change color during the first 24 hours.
Adults tend to care for the fry even after they hatch, but once they swim out on their own, they can be separated.
ADVICE:
It is a very popular aquarium fish, but before introducing it into our aquarium we must consider that once it is an adult, it is large and usually lives between 10 and 20 years.
Today, there are many ornamental variants of astronotus ocellatus, modified to be reared in aquariums and offering differences in morphology and coloration: tiger oscar fish, albino tiger oscar fish, red oscar fish, veiltail oscar fish, lutino red oscar fish and lemon oscar fish.
OSCAR FISH DISEASES:
HEXAMITE:
Oscar fish can be affected by a disease called Hexamita, which causes holes in the head.
This disease causes cell necrosis in the muscles of the head.
Hexamitiasis is caused by a protozoan called Hexamita, which is in the intestines of animals, which arrive there ingested with food.
Normally they are not a problem, unless the fish are subjected to stressful situations in the aquarium, as a result of an excessive number of fish, inadequate water quality, sudden changes in temperature or an inappropriate diet.
It can be a serious disease, if measures are not taken in time.
