Red Oscars

Standard and Albino

Astronotus ocellatus

Our Oscar varieties are indigenous to South America, ranging from the Orinoco River to Rio Paraguay. Oscars are a species belonging to the taxonomic family cichlidae or cichlids. The cichlid classification includes such other popular freshwater breeds as Discus, Angelfish, African Cichlids, Texas Cichlids (Rio Grande Perch), Jack Dempsey, Firemouth and Zebra Cichlids, Kribensis, Mozambique Mouth Brooder, Waroo and the Bumblebee Fish. Cichlids are widely distributed throughout tropical Africa, and South and Central America. Some species are found in southern Asia, and one species is native to North America. Unlike many freshwater aquarium fish, Oscars are quite tolerant of pH values slightly above or below neutral (pH 7). They also are comfortable in relatively hard water. Many cichlids share this tolerance, the most notable exception being the south american Discus.

Because they are so tolerant of widely varying water conditions, they are an excellent choice for the beginning aquarist. Be prepared, however, to invest in large quarters for them fairly early on in your hobby. Oscars grow up to 14 inches (35cm) in length in a surprisingly short period of time, and are best suited to a tank having a depth of at least 18 inches (45cm) and a length of 48 inches (120cm). They feel very at home in an aquascape consisting of standard aquarium gravel, rocks for cover and artificial plastic plants. Oscars have a propensity to dig in the substrate (gravel). It is a very natural behavior for them and should not be discouraged. It obviously makes the introduction of live rooted plants into the tank somewhat impractical. The bottom terrain will noticeably change almost daily, making your tank far more interesting to observe. Floating plants are more practical and will make a positive contribution to the ecology of the tank. Visit the Aquarium Ecosystems page for information regarding interaction of tank elements and their role in maintaining the good condition and ecological equilibrium of the aquarium water.

Three of our four Oscars are standard reds, and the fourth is an albino red. Albinism in Oscars appears to be somewhat common since the price for albinos is comparable to the price for the standard reds. I have also observed albinism in the Tiger Oscar variety. I personally know of one other variety, Black Oscar Wild, but I do not know if they share the albino characteristic. All of the Oscars I have encountered during my research are classified under a single species name, Astronotus ocellatus. The black and tiger varieties are marked with a distinctive black spot on the caudal peduncle. In the tiger variety the spot is surrounded by a thin, bright red ring. In the black variety the ring is silver. The red variety has a very small black spot on the caudal peduncle absent the encircling ring. The albino red has no discernable markings of any kind. Albino tigers have similar markings to the standard tiger, except that the markings are dark pink against the lighter pink albino background. All of the standard species are very darkly colored at the top of their bodies, down their face to the upper lip and straight back level with the lip to the edge of the gill cover. The lighter colors begin just below the dorsal fin and continue onto the underside. The fins are very dark in color with a translucent edging. The pectoral fins are transparent. Albino varieties are similarly patterned except in shades of pink. Albinos have pink eyes. Every quality aquarium store that I have encountered, including WalMart, has had a good selection of oscars, usually more than one variety. Most stores will order one for you if none are in stock.

Through our observations, Oscars appear to be agressive only toward their prey fish. In that regard they are truly a sight to behold. They are very effective predators. However, while they may chase other (non- prey) fish playfully, we have never observed them "picking" at fins or in any way harassing their tank mates. We have no idea how to distinguish gender in the Oscars, and don't know if either pair we have will mate. I would be very grateful for any information anyone visiting this page may have regarding sexing Oscars. There is an E-mail link at the bottom of this page. I am also interested in whether the Oscars' behavior will change toward other tank inhabitants if they do mate. It appears that Oscars can be included in a tank with other species, provided the tank size is sufficiently large that overcrowding is not a problem.

Although Oscars are very hearty, they are as susceptible to the usual aquarium diseases as any captive fish. Even the most meticulous aquarist will occasionally find their pet afflicted with white dots (ich), white fuzz (fungus) or some other equally insidious condition. The best policy for anyone keeping an animal in captivity is to develop a good relationship with the owner of the pet store. Try to make a point to chat with an owner or employee, who seems to have the best knowledge of fish, each time you go into the store. If you notice anything different about the behavior or appearance of your fish, describe it to your friend at the pet store, and ask their advice. There are a number of user friendly remedies that they can recommend. Most important of all is to observe your fish daily. It is the only way you will be able to diagnose any ailments in time to effectively treat them. We noticed our large Oscars turning themselves completely upside-down and vigorously swimming through the gravel at the bottom of the tank We had never seen them do anything like that before. Upon closer examination we observed white fuzzy looking patches on their backs and sides. Our pet store owner recommended a remedy that could be added directly to the water. Within a day or two the Oscars' condition was improving.

We have our Oscars in two tanks. The two older reds (22 months as of this writing) are in a thirty gallon hexagonal tank. The two younger oscars (5 months), one red and the albino are in a twenty gallon rectangular tank. Both tanks are rather simply aquascaped with gravel, medium sized lava rocks and plastic artificial plants. They both use Aqua-Tech 20-40 Gallon cartridge type recirculating filter systems. Each tank uses double air pumps ganged together and released through 10 inch (25cm) bubble curtains. Both have thermostatically controlled heaters to maintain an ambient temperature of 72-79 degrees farenheit. At 80 degrees farenheit and higher the oxygen transpires out of the water faster than the pumps can replenish it. At temperatures lower than 72 degrees farenheit the Oscars become sluggish and sometimes refuse to eat. The lower temperatures also cause the fish to become stressed making them more susceptible to disease and infection. Their normal food is large cichlid pellets. Once or twice a week we add a dozen or so live goldfish to each tank which is like ice cream to them The live food rarely lasts more than an hour.

Our Oscars are hugely entertaining to watch. The older ones are over six inches (15cm) long. They put their noses up to the glass and watch us as much as we watch them. They know when we have food, and rise to the surface waiting to be fed. I have brought them earthworms from the yard, and they ate them with great relish. Evenings I catch bugs around the porchlight and throw them on the surface of the water, and they too are promptly snapped up. Debbie has them trained to fetch. She moistens her finger so that a food pellet will cling, and holds it a couple of inches above the surface of the water. They jump clear out of the water to get the pellets. While they are at the surface at feeding times we have petted them on their heads. Debbie calls them her little mutts. They scoop up large mouthfuls of gravel off of the bottom and swim halfway up the side. Then they spit the gravel against the glass, ostensibly to get our attention. We put a Blue Gourami in the tank, and intending to create a refuge zone for the gourami to hide in, we put a section of hamster habit-trail at the bottom of their tank. We were afraid the Oscars would try to eat the Gourami. The Gourami never used the hiding place, but the Oscars pick it clear up and move it all over the tank. They butt it with their heads and hide it behind the plants. The next time you look, it's out in the middle of the tank again. It has proved to be the best Oscar toy we could possibly have provided for them.

We put a Chinese Algae Eater into the large tank when it was a little over two inches (5cm) long to help in controlling the debris on the bottom. When it was first introduced, the Oscars tried their best to have it for dinner. The little scavenger was so quick that they never managed to succeed in their quest. The Algae Eater has been in the tank for four months now (since 12/96), and is over five inches (13cm) long. It is not only out of danger of being eaten, but seems to enjoy taunting the Oscars. It swims up the surface of the glass until it nudges an Oscar on the chin, then bolts under the cover of a rock. We never feed the Algae Eater. It thrives solely on the tank debris.

About three months ago (1/97) we noticed an infestation of small white worms in the large tank. The worms appeared to be tapered at both ends (unlike worms that attach themselves to fishes), and in the opinion of two of the pet store owners seemed benign. We could observe the worms crawling over the surface of the Oscars, but they did not seem to be in any way harmed by the worms. So we looked for a sort of "holistic" solution to the infestation. We introduced the Blue Gourami, mentioned above in relation to the Habit-trail tube, after learning they are particularly fond of eating small worms. The Gourami was small enough at the time to be food for the Oscars, and we watched with some trepidation for a couple of days. The Gourami is nowhere near as fast or evasive a swimmer as the Algae Eater, so we were very surprised when it survived the first couple of days. The Gourami never hid from the Oscars. To the contrary, it swam right between the two of them with complete impunity as if it were invisible to them. The Gourami began eating the worms ravenously, and now has them under control. It comprises a continuing live food source for the Gourami. The Gourami has now grown considerably and flutters its body along the side of the Oscars in what I now know to be a Gourami mating behavior. The Oscars respond by cupping their bodies in return, and appear to genuinely appreciate the Gourami's gesture. It beats all I've ever seen regarding the Oscars, but it appears at least in this case that a Blue Gourami makes a good companion fish for Oscars.

The younger, smaller Oscars in the 20 gallon tank are also entertaining, but in different ways. They also dig and rearrange their surroundings daily. One of the plastic plants we used in furnishing their tank is colored red with white on the tips. They hate it. Whether it is the color or the shape or something else, they attack it constantly. I can bury it under three inches of gravel substrate, and within an hour they will have pulled it out. We had such good luck with the Algae Eater in the large tank we wanted to put one in with the youngsters as well. In two tries now the Algae Eater has not survived the day. The cover in the 20 gallon tank is much better than it is in the larger tank. Either we are getting less evasive Algae Eaters or the younger Oscars are more skillful predators than the older ones. The younger Oscars have a policy that if it moves - it's food. I dangled cooked spaghetti noodles in their tank simulating worms. They ate several each.

Return to the Aquarium Links Page for information regarding our other tanks and fish. Comments and input regarding your own aquaculture experiences are welcome and enthusiastically solicited. Please write to me at the E-mail link provided below. I thank you.

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LinkExchange Member

Gary Churchman
garydebc@silcom.com

Copyright © 1997 Gary Churchman
This Home Page was created Friday, March 14, 1997
Most recent revision Wednesday, July 2, 1997