What Do Oscar Fish Eat?

Mychelle Blake
Contributor: Donna Sundblad
Red Oscar

Thinking about getting an oscar fish and wondering what they eat? Find out which foods are best for these popular cichlids, as well as how much and how often to feed them to have healthy, robust fish.

Live Foods for Oscars

In the wild, oscars eat a varied diet which consists of a variety of insects and crustaceans. While oscars eat many types of live foods, not all live foods are good for them. Just as pellets come in different sizes, the size of the live food fed to your pet should be appropriate for the size of the fish eating it.

Recommended Live Foods for Oscars

Always purchase your live food from a reputable pet store or you can raise your own if done in your home. Never feed insects taken from the outside as these can be exposed to pesticides which can make your fish ill. Recommended live foods include:

  • Black soldier fly larvae
  • Crickets
  • Grasshoppers
  • Locusts
  • Mealworm beetles (mature mealworms)
  • Mealworms
  • Wax worms
  • Mussels
  • Plankton
  • Prawns
  • Shrimp
  • Small fish such as rosy red minnows and guppies. Avoid feeding goldfish.

How Often to Feed Your Oscar Fish Live Food

If you choose to feed live oscar food, you should add just one or two feeder fish to the tank at mealtime. Filling the tank with feeder fish and allowing your oscar to feed at will has some definite drawbacks for him, which include:

  • Spoiling your pet so that he rejects any other type of food
  • An unbalanced diet which can affect the fish's health
  • Causing him to become obese as small fish contain a lot of fat
  • Causing a deadly ammonia surge by overcrowding the tank

The drawbacks for you include:

  • The regular expense and inconvenience of stopping at the pet store for oscar food
  • The need for more frequent water changes and tank cleanings
  • The possible need to medicate your fish because he has caught a disease introduced to the tank from a feeder fish
    Oscar swallowing a fish; copyright Marcelo Saavedra at Dreamstime.com

Feeder Fish Cautions

Oscars need a balanced diet, so feeding them small fish is fine if you limit it to just a few fish a week. However, there are a few import tips to keep in mind.

  • Always choose extremely healthy feeder fish. If these fish are sick or diseased, they can pass along diseases to your oscar, such as the disease known as "hole in the head."
  • If you have difficulty getting healthy feeder fish, consider breeding your own. Guppies are prolific breeders and are often used as feeders.
  • Feeder goldfish are not the ideal fish for an oscar's diet because they are prone to disease since they are typically kept in overcrowded tanks. If you must feed goldfish, be very selective and never purchase from a tank that contains any sick fish.

Commercially Prepared Oscar Food

When shopping for commercial foods to feed your oscars, look for foods designed for cichlids. A large selection of pellet foods are available, as well as foods that are frozen, freeze-dried, or canned. Pellets come in different sizes and shapes to offer a selection for juvenile and adult oscars. When choosing pellets or other food for your pet, make sure the food is smaller than the fish's mouth.

Popular Commercial Foods for Oscars

This short list offers popular commercial food choices suitable for oscars:

  • Beef heart is sometimes recommended but are high in fat so use only as an occasional treat.
  • Frozen bloodworms and brine shrimp are suitable for baby oscars.
  • Hikari Cichlid Gold are pellets which contain necessary vitamin C and also float, which helps you to see if the oscar has eaten everything.
  • Canned mealworms are a good option if handling live worms is unappealing to you, or you don't have access to a local shop that sells live ones.
  • Canned crickets are similar to canned mealworms and are easier to feed than the live version and can be stored for longer.
  • Tetra Jumbo Krill is a good option for helping your fish to have more vibrant coloring.
  • Freeze dried insects such as crickets, grasshoppers, mealworms and bloodworms, can be purchased as well.
  • Hikari Tropical Wafers are made with algae, which can provide your oscar with healthy plant matter.

Homemade Food to Supplement Your Oscar's Diet

Since wild oscars will eat plant matter, you can chop up vegetables like cucumbers and zucchini and give them to your oscar in small quantities. You can also feed them tiny amounts of frozen peas. They can also eat shelled nuts, preferably tropical nuts and even some fruits. Common fruits given to oscars include bananas, cantaloupe, oranges and watermelon. Make sure if you feed fruit, you remove any seeds before feeding. Some oscar owners may also feed them bread, which will not harm your fish but will not add anything nutritious to his diet.

Oscar Fish Food for Color

One thing to note about feeding your oscar is that certain foods can actually bring out more of their color, especially red tones. Look for foods with astaxanthin, which is present in krill shrimp. Peas have also been known to make their colors more noticeable.

How Much to Feed

Regardless of which foods you decide to feed your oscar, it's important not to overfeed fish. Oscars have different needs based on their developmental stage.

Feeding Juvenile Oscars

If your oscar measures less than four inches, it is a juvenile. These fish are fast growing, so smaller oscars need to eat more often.

  • For fish less than four-inches long - Feed at least three times each day until the fish's stomach look somewhat rounded. This should be no more than three minutes per feeding session. Feed about three to four pellets at a time and wait until they are finished before you add more pellets.
  • For fish at least five-inches long - Feedings can be cut back to twice a day and you can start adding in live food like insects.

Feeding Adult Oscars

Once an oscar reaches a year of age, it is considered an adult. Adults should not be fed more than once a day. In fact, most adults do well when fed about four days a week. This gives the digestive track a day to clear completely before feeding resumes.

Food Quality and Balanced Nutrition Are Key for a Healthy Oscar

Feeding an oscar isn't as difficult as it may seem. The main thing to remember is that oscars are carnivorous and require a diet with proteins such as shrimp, insects and smaller fish. The diet for oscar fish in their natural environment consists primarily of larvae, insects, fish, crustaceans and plant debris. Remember to keep all these factors in mind when creating your oscar's diet plan:

  • Always choose the highest quality food available.
  • Feed a combination of live food and commercial food to ensure your pet gets a well-rounded diet. You should aim to feed about 80% pellets and 20% live foods and plants.
  • Making sure your oscar has plenty of protein is also important for helping to grow faster.
  • Make sure you provide variety in his diet as these fish will not eat the same items every week in their natural habitat.
  • Observe your pet when he eats and remove any uneaten food two to three minutes after feeding so it doesn't foul the tank.
  • Watch your pet's condition. If he looks fabulous and seems active, alert and healthy, you probably hit the right food combo and feeding schedule.
  • If your oscar doesn't eat the food you give him, you may need to try different options to find the items that he prefers.

When Your Oscar Stops Eating

An oscar can suddenly stop eating for a few different reasons, but it's usually a signal that something is wrong. These steps may help resolve the problem:

  • Test the water in the tank; the pH should be between 6.0 and 8.0.
  • Try a different type of food. Oscars need variety in their diet.
  • Trying doing a water change of 25 to 50%.
  • If the water condition is fine, you've tried different food, and the oscar still won't eat, stop feeding your fish for a few days. Usually a healthy fish will start eating again when food is reintroduced.

If you take these steps and your oscar continues to refuse to eat, talk to a veterinarian or your local aquarium shop expert.

Feed Your Oscar for a Long and Healthy Life

These simple suggestions can help your oscar live a longer and healthy life. Always remember to focus on a primarily carnivorous diet, but don't forget to include some plant-based items to their diet, and make sure your fish does not become obese as oscars can be greedy eaters who will consume as much as you give them.

What Do Oscar Fish Eat?