What Do Oscar Fish Eat? | The Oscar Fish Diet Guide

Oscar Fish (Astronotus ocellatus)
Oscar Fish (Astronotus ocellatus)

What Do Oscar Fish Eat?

Oscar Fish (Astronotus ocellatus) are omnivores, which means they eat both meat and plant-based foods. Within these major food groups, there are a lot of different types of food that they eat. Even though cichlid pellets would be their staple diet in an aquarium environment, it is important they are fed a varied diet. In addition to pellets and other dry foods, their diet can be supplemented with live foods, worms, plants, small crustaceans, insect larvae, and various other invertebrates. This will help them achieve nutritional balance and mimic their feeding habits in the wild.

Best Foods to Feed Oscar Fish

The best foods to feed Oscar fish would be high quality cichlid pellets, insects and worms, veggies and fruits, and seafood. While there are many different types of foods that Oscar fish can eat, feeding the best foods would help allow them to grow, thrive, and maintain their health throughout their long lifespan.

Here’s a breakdown of the best foods to feed Oscar fish:

  • High Quality Cichlid Pellets: High quality cichlid pellets should be their staple food, as it contains a nutritionally balanced formula. This should comprise the majority of their diet. While there are many pellet foods available on the market, it is important to feed a high quality pellet food such as Hikari Cichlid Gold Floating Pellets. The quality ingredients consisting of protein, fats, vitamins, and other essential nutrients would help the Oscar fish thrive. Furthermore, out of the various types of dry foods, pellets are recommended since they tend to be less messy. Other dry foods such as flakes, crisps, wafers, and tablets may get messy when feeding to Oscars.
  • Insect and Worms: Invertebrates such as insects and worms would be a natural part of their diet. In fact, it would consist of a significant portion of their diet. Therefore, incorporating them into their diet in an aquarium would only make sense. Some of the best insects to feed Oscars would be crickets and mealworms. In regards to worms, live earthworms that are freshly dug out of a garden would be ideal. It would be important to make sure that they are sourced from an area that does not contain disease, pesticides, and other chemicals that might harm the fish. If you don’t have a safe and reliable source to dig the earthworms from, farm raised options may be suitable.
  • Veggies and Fruits: As omnivores, it is important that veggies and fruits are incorporated into an Oscar’s diet as well. While there are many different types of veggies and fruits that you can feed Oscars, peas are some of the best options. Peas are nutritious, and it helps enhance the color and vigor of the Oscars. They are also very convenient. Simply purchase a small bag of frozen peas at the grocery store, and keep them in your freezer. When you are ready to feed them, grab a few and rinse them under cold water to thaw, then throw them into the tank once at a time. While some Oscars may be hesitant to eat them at first, they should eventually learn to enjoy it. In addition to peas, other veggies and fruits that can be fed to Oscars would include spinach, cucumber, apples, and bananas.
  • Seafood: Some of the best seafoods you can feed Oscars include shrimps, clams, squid, and scallops. They are often available as fresh or frozen foods at the grocery store. If they are frozen, thaw it under cold water and cut it into an appropriate size before feeding. Be careful not to overfeed, and alternate between different types of seafood in order to vary their diet.

Oscar Fish Food List

As omnivores, Oscar fish are able to eat a wide variety of foods. From meaty foods to plant-based foods, their diet can be varied, and it should be. In the process of looking for foods to add to their diet, you may wonder if Oscar fish can eat a particular food or not.

Here’s a list of foods that can be fed to Oscar fish:

  • Cichlid Food: Cichlid food is an excellent choice for Oscar fish as it is specifically designed for their dietary needs. In fact, cichlid food such as a high quality pellet food should be their staple diet. All other foods besides this should only be considered a supplement to this main food source.
  • Tropical Fish Flakes: Tropical fish flake is a good choice for feeding Oscar fish, since it contains nutrients that are closely matched with the Oscars’ needs. However, flakes can get messy for larger Oscars. While flake foods may be suitable for smaller juvenile Oscars, pellet feed may be better as the Oscar grows larger.
  • Algae Wafers: You can feed algae wafers in small quantities to Oscar fish. While it shouldn’t be their sole source of food, it will help with their intake of plant based foods.
  • Insects: Oscars feed on insects in their natural habitat. Many types of insects such as crickets, locusts, grasshoppers, cockroaches, ants, moths, spiders, waxworms, and various insect larvae can be fed to Oscar fish. However, it is important to make sure they are free of disease, parasites, and chemicals. Keep in mind that insects such as stink bug, june bug, and various species of beetles may have a hard exoskeleton, making it potentially unsuitable for feeding Oscar fish.
  • Snails & Slugs: Oscar fish can eat snails and slugs. Even though snails have a hard shell, Oscars are known to break the shells and devour the snails inside. It is important to make sure they are free of disease, parasites, and chemicals.
  • Shrimps: Shrimps are one of Oscar’s favorite foods. While they shouldn’t be their primary food source, they are great nutritious treats that are rich in protein. Shrimps are available in various formats such as raw, cooked, fresh, frozen, and dried. They are all suitable for feeding Oscar fish, and they are often readily available in grocery stores. If they are purchased frozen, thaw a few pieces under cold water to thaw, then cut into appropriate sizes for feeding.
  • Seafood: In addition to shrimp, seafoods such as scallops, clams, mussels, squid, and prawns are great food sources for Oscar fish. Many of these are available as fresh or frozen seafood. For frozen seafood, they should be thawed under cold water, then cut into appropriate sizes for feeding.
  • Brine Shrimp: Brine shrimp can be fed to small Oscar fish. They are great food to feed Oscars, as they are rich in protein. They are available in live, frozen, and freeze-dried form. All forms are suitable for feeding Oscar fish. However, due to the small size of brine shrimp, it would only be suitable for feeding small juvenile Oscar fish.
  • Ghost Shrimp: Oscar fish will eat Ghost shrimp (Palaemonetes Paludosus). Ghost shrimp are also known as feeder shrimps, and the Oscars will readily consume them. Since Oscars do eat various invertebrates in their natural environment, this would closely resemble their natural diet.
  • Krill: Krill can be fed to Oscar fish, and they are a good source of protein, carotenoids, and other nutrients. Krill are usually available frozen or freeze-dried, and both are suitable for Oscar fish.
  • Earthworms: Earthworms can be fed to Oscar fish. They are great sources of protein, minerals, vitamins, and other nutrients. If you can dig up fresh earthworms such as nightcrawlers and redworms from your garden, you would have a source of free food for your Oscar fish. However, it is important that they are free of disease, parasites, and chemicals.
  • Bloodworms: Bloodworms are a good source of protein for your Oscar fish. They are great treats, but due to their small size, it would only be suitable for smaller juvenile Oscar fish.
  • Mealworms & Superworms: Mealworms and superworms can be fed to Oscar fish. They are great sources of protein, vitamins, and minerals. It is important that live mealworms and superworms are purchased from reputable dealers. It is recommended to rinse them in clean water before feeding it to the Oscars.
  • Vegetables: Oscar fish will eat various types of vegetables. Types of vegetables that they eat include peas, cucumber, zucchini, broccoli, cauliflower, carrots, spinach, and lettuce. Vegetables that are hard can be boiled or blanched, and then cut into appropriate sized pieces for feeding.
  • Fruits: You can feed various types of fruits to Oscar fish. Types of fruit that can be fed to Oscar fish include bananas, plantains, pumpkins, pears, sweet potatoes, oranges, cantaloupes, watermelon, apples, mangoes, peaches, grapes, apples, strawberries, and blueberries. Fruits that are hard can be blanched, and they should be cut into appropriate sizes for feeding.
  • Live Plants: Oscar fish may eat live plants in your fish tank. While most Oscars will probably only damage the plants instead of eating it, they may eat it in small quantities. For example, they may eat live plants with soft leaves such as duckweed.
  • Raw Fish: You can feed fish such as salmon, tilapia, sardines, and catfish to your Oscar fish. They are often available at the grocery store as fresh or frozen fish. Frozen fish should be thawed in cold water, then cut into smaller pieces that are appropriate for feeding. It is important that Oscars are fed fish that are good quality. Needless to say, the fish that are canned in oil, salted, or seasoned must be avoided.
  • Live Feeder Fish: Live fish such as feeder goldfish and feeder guppies can be fed to Oscar fish. Since Oscars in the wild eat smaller fish on a regular basis, they will not hesitate to eat the feeder fish. However, do keep in mind that live fish should not be their only source of food, and live fish is not required for an Oscars’ proper growth and overall health. Due to ethical considerations, some fishkeepers decide not to feed live fish to their Oscars. If you do decide to feed live fish to your Oscars, make sure that they are free of bacteria, viruses, and other diseases.
  • Eggs: Oscar fish can eat hard boiled eggs, and it provides protein and other nutrients. However, it is recommended to feed in small quantities and be careful not to overfeed as it can foul the water quality and become toxic for the fish.
  • Nuts: Oscar fish can eat nuts such as peanuts. In the wild, Oscars would have access to lots of tropical nuts and seeds that naturally fall into their waterways. They have been known to eat nuts that they find in the flooded forest.

Oscar Fish Food to Avoid or Limit

Oscars need a varied diet, so many owners make the effort of exploring different types of food to feed their Oscar fish. They are often met by surprise, since Oscars will eat a wide variety of foods offered to them. However, just because an Oscar fish will eat it, it doesn’t mean it’s good for them. Some foods can cause harm to their health.

Here’s list of Oscar fish foods that should be avoided or limited:

  • Processed Foods: Processed foods such as chips, crackers, and bread contain little to no nutritional value and may cause health problems for your Oscar fish.
  • Bread: Oscar fish should not be fed bread. Bread adds very little to no nutritional value to their diet. Moreover, the problem arises when bread expands after being swallowed by an Oscar. This can cause digestive issues and other overall health issues for the fish.
  • Spicy Foods: Spicy foods can be harmful to your fish’s digestive system and may cause irritation and inflammation.
  • Meat: Oscar fish do eat meaty foods, but meat such as beef, hot dogs, bologna, and hams should be avoided. Among other factors, the high fat content would make it very difficult for the Oscars to digest it.
  • Beef Heart: Feeding beef heart to Oscar fish should be limited. While some fishkeepers do feed beef heart to their aquarium fish to enhance their growth, feeding beef heart to fish regularly can have negative consequences. Oscars are not used to eating mammals as their staple diet, and the high fat content in beef heart makes it difficult for the Oscar fish to digest.
  • Chicken: While Oscars may eat chicken if it is offered to them, it’s not a recommended food source. This includes raw chicken, cooked chicken, and chicken liver. Oscars are not used to digesting these foods. Regular consumption of chicken may have negative consequences to their health.
  • Mouse: While Oscar fish may eat small mice such as pinky mice if given the chance, it is not recommended to feed it to them. Their stomachs aren’t designed to digest land animals like mice. There is also the risk of mice carrying disease as well. While Oscar fish may eat mice and other small animals in their natural habitat, that would be a very rare occurrence.
  • Lizards: Oscar fish may eat small lizards if given the opportunity, just as they might in their natural environment. However, this would be rare, and not a part of their staple diet. Considering the risk of introducing disease, and the availability of better alternatives, feeding lizards to Oscars should be largely avoided.
  • Cheese & Dairy Products: Oscar fish should not be fed cheese and other dairy products. They are unable to digest the fat and protein included in dairy products due to a lack of enzymes to break them down. Therefore, feeding them cheese can have adverse effects on their digestive system.
  • Dog Food: While Oscars may eat dog food if it is offered to them, it is not recommended to feed it to them. Many dog foods contain cooked fats in beef, as well as many other ingredients that are difficult for Oscar fish to digest.
  • Turtle Food: Oscars will eat turtle food and they aren’t harmful to them, but it may not provide the optimal nutrition for an Oscar fish. Therefore, it should be limited.
  • Betta Pellets: Small Oscar fish may eat betta pellets, and it may not hurt them in small quantities. However, betta pellets are not designed for Oscars, so it should be limited.
  • Koi Food: Oscar fish may eat koi food, and it may not hurt them in small quantities. However, koi food is not designed for Oscars, so it should be limited.
  • Goldfish Flakes: Oscars may eat goldfish flakes, but it should be limited. Goldfish have different dietary needs than Oscars, so goldfish flakes are not ideal for Oscars.


How much should I feed my Oscar fish?

Feeding your Oscar fish depends on a few factors such as its size, age, and overall health. Here are some general guidelines:

  • Juvenile Oscars: They have a high metabolism and should be fed 2-3 times a day. The amount of food should be what they can consume in 2-3 minutes.
  • Adult Oscars: They should be fed once a day or every other day. The amount of food should be what they can consume in 2-3 minutes.

Remember, overfeeding can lead to health problems such as obesity and poor water quality due to uneaten food. It’s always better to underfeed than overfeed. Oscars are opportunistic feeders in the wild and can go for several days without food.

Also, a varied diet is important for the health of your Oscar. This can include specially formulated cichlid pellets, frozen or live foods like shrimp and worms, and even some fruits and vegetables.

Please note that these are general guidelines and individual fish may have different needs. Always observe your fish’s behavior and adjust feeding accordingly. If you notice any changes in your fish’s eating habits or general behavior, it might be a good idea to consult with a vet or an aquarium professional.

How often should you feed Oscar fish?

The frequency of feeding Oscar fish depends on their age and size:

  • Juvenile Phase (under 6 months): Oscars might benefit from feeding 2-3 times a day to support their growth.
  • Adolescence (6-12 months): Feeding can be adjusted to twice daily, with slightly larger portion sizes.
  • Adult Stage (1-3 years): Mature Oscar fish may be content with feeding once or twice a day.
  • If the fish are 4-6 inches in size, you can feed them daily but alternate the frequency between once a day to twice a day.

It’s best to ensure they finish the food within several minutes to avoid overfeeding and potential health complications. Offering a variety of foods is also recommended for a balanced diet.

How long can Oscar fish go without eating?

Oscar Fish can go anywhere between two weeks to up to four weeks without eating. How much your Oscar Fish can go without eating depends on its age and size. A juvenile Oscar Fish can go up to two weeks without eating and an adult can go up to four weeks and even more without eating anything. However, just because they can go on for weeks without feeding doesn’t mean it’s healthy for them. If your Oscar fish hasn’t been eating for a while even though it’s being offered food, then it could be a cause for concern.

Why is my Oscar Fish Not Eating?

There could be several reasons why your Oscar fish is not eating:

  • New Environment: Sometimes new Oscars might not eat right away. It’s normal for fish to be shy when they are first introduced to a tank. If this is the case, it’ll probably be fine if you give the fish several days or even a week to get used to things.
  • Unappealing Food: The Oscar fish might be bored of what you’re feeding it. Sometimes the Oscar fish might stop eating in an attempt to hold out for something better. If you only feed the Oscars flakes and pellets, it’ll get bored of what you’re feeding.
  • Poor Water Conditions: Oscar fish may refuse food in poor water conditions. Use a water testing kit often to make sure the parameters are ideal for your oscar fish.
  • Bright Lights and Loud Sounds: Oscar fish may refuse food under bright lights or loud sounds.
  • Overfeeding: Overfeeding may also cause them to stop eating or spit out food.
  • Stress from Tankmates: They may also be stressed from their tankmates.
  • Disease or Parasites: Oscars occasionally stop eating due to illness.
  • Poor Water Quality: Oscars may also stop eating due to poor water quality.

If your Oscar fish still doesn’t eat normally after a good bit of time has passed, you might need to look into other things that might be wrong. You can try varying their diet with live food like shrimps, worms, snails, guppies, insects, larvae, peas and soft veggies. Soaking pellets or flakes in garlic juice may ignite the senses and desire in your oscar fish to try it out.

Why does my Oscar Fish spit out its food before eating?

 Oscar fish may spit out their food due to a variety of reasons:

  • Poor water conditions: Oscar fish may refuse food in poor water conditions. Use a water testing kit often to make sure the parameters are ideal for your oscar fish.
  • Unappealing food or overfeeding: Loud sounds, unappealing food or overfeeding may also cause them to stop eating or spit out food. If you feed the same food to your oscar fish, they may protest it by going on a hunger strike until you give them something new.
  • Moody behavior: Oscar fish display moody behavior sometimes and a hunger strike could be their way of showing it.
  • New Tankmates or New Tank: An oscar fish may need a few days to get adjusted to a new tank or new tankmates.
  • Bloating: A bloated oscar fish won’t want to eat unless they can relieve themselves. Consider adding peas to help them move out the waste.

If your Oscar fish is spitting out its food, you might want to try feeding it different types of food like shrimps, worms, snails, guppies, insects, larvae, peas and soft veggies. You can also try soaking pellets or flakes in garlic juice as it may ignite the senses and desire in your oscar fish to try it out. Please try to slow down when feeding an oscar fish that is spitting out its food or refusing to eat. Try to space out each softened pellet or flake. Place 1 pellet in the tank every 10 seconds or longer.

Remember that Oscar fish can go without food for 2-4 weeks, so don’t worry too much if they refuse to eat for a while. They will eat when they are ready.

What Do Oscar Fish Eat in the Wild?

In their native habitat in South America, Oscar fish enjoy a diverse diet. The majority of their diet would consist of insects, insect larvae, and smaller fish. In addition, they would eat many other types of food as well. Here’s list of foods that an Oscar fish would eat in the wild:

  • Insects
  • Insect Larvae
  • Small fish
  • Snails
  • Crabs
  • Shrimp
  • Crayfish
  • Worms
  • Tadpoles
  • Frogs
  • Newts
  • Nuts from Tropical Trees
  • Fruits
  • Plant matter
  • Algae
  • Detritus

Do Oscars Eat Other Fish?

Even though Oscar fish are not obligate piscivores, Oscar fish in the wild are known to eat other small fish. In many bodies of water, Oscar fish would be considered to be on the top of the food chain. They would prey on various smaller fish that exist in the rivers of South America. In fact, the majority of their diet may consist of fish when they are abundantly available. For example, during the dry months when bodies of water would shrink, all of the fish would be forced to congregate into a relatively confined area. This would give the Oscar fish an opportunity to prey on the smaller fish with little effort. In contrast, during the rainy season, the smaller fish would expand across the flooded forest. During these rainy seasons, Oscar fish may resort to other food sources more often.

Will Oscar Fish Eat Their Tank Mates?

If they are small enough to fit into their mouths, there is a high chance that the Oscar fish will eat their tank mates. For example, small fish such as Neon Tetras, Guppies, and Platies are very likely to be eaten by Oscars. Even larger tank mates such as Silver Dollars, Angelfish, and baby turtles can be eaten by Oscars if they are juvenile fish that are small enough.

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