Oscar Cichlid Astronotus sp Venezuela aff ocellatus in the wild

By Ivan Mikolji / 2014

Since 2006 I have been going to a very special spot in the Venezuelan llanos. This spot has clear water for a very short period of time in the rainy season. When I get there and start putting on my gear I start to get very impatient. I start to hurry, I dive in the water and start looking for some old friends, hoping they were not eaten by piranhas, crocs, or people since my last visit. I swim around, looking from side to side hoping they are still among the living. Once I spot them and recognize them by distinctive traits, I am happy and feel a sense of relief so I can relax. It is like visiting family, my Oscar family; and they are so wild!


Imagine standing on a flat plain with scattered tree patches and short brush. The only man made things around are the pothole road, your car, barbed wire fences made out of tree logs, and the occasional domestic cattle hybrid. The horizon stretches as far as your eyes can see. Nimbus cloud patches show various storm systems with heavy rainfall far, far away. Despite the 32° c. ambient temperature, a soft tropical breeze makes it feel 27° c.; just perfect! It is the rainy season so the area has been naturally landscaped to a majestic flooded grassland, savanna biome. These are the Venezuelan Llanos.



My very special spot is locally referred to as an Estero (es-tay'-ro) which is the Spanish word for inland river estuaries. This estero habitat is quite unique because it is about 800Km away from the coast and fed exclusively by rainwater. In the rainy season the estero gets filled up and drains into the nearby rivers. In the dry season the place dries up and no water is left, not even a puddle. It’s quite different from typical estuaries which are located near the coast, get their waters from a river, are brackish, and drain directly into the ocean and usually do not dry up. The water parameters are: pH-under 5, KH-less than 20mg/L (ppm), GH-less than 10mg/L (ppm), Temp: 29 ° to 31 ° Celsius. This is the hottest, large aquatic habitat I have ever tested. The water temperature is actually the opposite of the regular rainy season water temperatures where cold is predominant as a breeding trigger. The closest place that resembles this estero would be a small scaled Pantanal in Brazil.



Astronotus ocellatus are medium large cichlids grouped by us in the Astronotinae subfamily. There are only two species described in the Astronotus genus which we named Acrassipinnis and Aocellatus. Their given nickname is Oscar Cichlids or simply Oscars. When I say we or us, I refer to humans because Oscars have no clue about all of this. What is important to an Oscar in the wild is to look for food, grow, look for a mate, reproduce, take care of their offspring and survive the rainy and dry seasons. In that respect we have a lot in common with the Oscars as with any other living thing on earth, don’t we? I will continue to refer to Aocellatus as an Oscar from now on because common names do not change with time compared with scientific names and will make this article be up to date.



Oscars are present in many countries in South America including Venezuela, Peru, Ecuador, Colombia, Brazil, Paraguay, French Guiana and others. They have adapted to diverse water conditions, river systems, and coexist with different species of fish that differ from one basin to another. Many ichthyologists think that there are more than one species of Oscars. To the extent that scientists refer to the Venezuelan Oscar as Astronotus sp Venezuela. Future revisions of the genus will clear this up and let us know if there are different species or just some closely related morphs. When scientists and other field investigators and explorers collect tropical fish specimens in the wild for scientific or aquarium related purposes, they usually measure the Ph, temperature of the water, time, date, how they captured it, people involved and the locality. Then they bag the fish if it is destined for the tropical fish business, or dissect the fish, analyze the content of the stomach, and all the other scientific dissection stuff, if it is scientifically intended. If a local collects them, they go into a frying pan or a stew pot. I usually do not catch fish at all, I try to hang out with them, see what they are doing, video and photograph them underwater.



Even though my special spot is as big as a football field, it feels small compared to seeing how vast the land is around it. This place is magical. The water clarity varies depending on the amount of rainfall, if a herd of cattle, horses, capybaras, crocs, or any other large animals have been taking a bath, stirring up the bottom.


When I spot my Oscars in the wild they do not swim away as many other fish do; however, they do not approach me curiously or hungrily either as other fish do.  They actually are like people with a personality. Oscars seem to be a very intelligent fish. Double O, the name I gave to the Oscar that has a double eyespot or ocellus is a “cool” fish. He is never afraid of me. He always sees me and keeps on doing his Oscar business. Even if I get up close, he just swims towards my camera and then keeps on swimming past one of my ears. He is relaxed. The Astronauts, a loyal family of Oscars always stay two meters away from me at all times. The male has an eyespot that seem to have small cat ears if seen vertically. When they have fry they will stay even further away. In order to take an image of them I had to trick them. I let them swim behind a large group of aquatic plants. Once I was out of their site, I quickly swam in front of the wall of plants and waited for them at the end. Once they swam past the aquatic plants they were able to see me but by then, the shot was in the can. This couple seems a bit paranoid all the time even when they are not breeding. They do not swim away quickly, they just choose to be a bit away from me. They probably think I am some sort of croc they have never seen before. The last of my Oscar friends is Gray, and as his name says, he is simply gray. He has no orange on the sides of his body. Mr. Gray is always hungry and doesn’t stop looking for food. It is quite hard to keep up with him. He comes and goes from here to there, desperate for his next meal and that is all he does.



Double O, The Astronauts, and Mr. Gray have taught me many things. They have let me into their domain and shared their day to day chores with me. As I work in their homes for 7 to 10 days a season for the last 8 seasons I have spent around 64 days swimming in their habitat. I know their preferred spots and they make me feel like I am not alone as I work.


One of the most curious things I have seen the Oscars do in the wild is feed. People may think that they prey on fish as they do in aquariums but in the wild I have never seen them chase a fish. You may also think he is a mid-aquarium dweller which is completely wrong. Oscars in the wild are top water dwellers, almost surface dwellers. As you can see in the photographs, I was able to take amazing underwater reflections because that is where they spend their day. What they actually do is inspect every branch, leaf or aquatic plant on the water surface. They are always swimming in a 45 ° angle 10 to 20 cm below the water surface. They approach any plant, leaf, branch, or stick floating on the water surface and push it a bit with their mouths. They then stay still and watch. If nothing happens they approach another floating or submerged branch and hit or lift it up with their forehead. All of a sudden an insect jumps into the water, scared by the movement and at this moment the Oscar strikes. They are insect eaters and swallow them whole. This is what they do all day long. They inspect, push, wait, swallow, and then go in search of the next victim. Oscars preferred menu specials include crickets, grasshoppers, spiders, and some large ants. Aquatic invertebrates and fruits are practically nonexistent in the estero habitat but that does not mean they are not present elsewhere.



Leaving their habitat is always a very sad time for me. Even though some people might think I’m crazy, deep inside I have gotten to feel a part of their world. Before leaving I take a good look at the landscape, I take a deep breath and wish them the best. The estero habitat dries up completely in the dry season. Where do they go? How far do they travel? What do they do? It is all a mystery to me. I’m just so happy to see them again year after year.


This article has been published at:
  • Practical Fishkeeping Magazine - July 2014
  • AQUAmag Magazine N°30 - 2016

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