Do Oscar Fish Bite? {Can I Stop It?}

Are you thinking twice before sticking your hand in your oscar fish tank? Are you thinking do oscar fish bite?

Are they agressive when you put your hand in their tank?

In this article, we’ll discover if oscar fish bite and how bad it could be.

Do Oscar Fish Bite?

Yes they do. Oscar fish are known to be territorial and aggressive at times when they feel threatened or stressed. Sticking your hand in there invades their space and they may bite back.

Try not to worry. Put that phone away because you won’t need an ambulance.

Oscar fish are not going to attack you or tankmates feverishly to the death.

They nip and bite to ward off potential threats and remind them that oscar fish need some breathing room.

Do Oscar Fish Have Teeth?

Oscar fish belong to the cichlid family of fish who have teeth lined up in their jaws and in their throats too!

  • Mouth teeth
  • Pharyngeal teeth

Pharyngeal teeth in the throat help break down and process larger bits of prey. The teeth in their mouth helps them to grip or grasp objects and food.

Do Oscar Fish Bite Hands and Fingers?

Oscar fish bite fingers and hands when they are:

  • uncomfortable
  • stressed
  • cramped
  • moody
  • in poor quality water
  • next to unsuitable tankmates

If your oscar fish is relaxed, comfortable, well-fed and has plenty of room to swim around without feeling cramped, then your fingers and hands should be safe.

Oscar fish have a temperament that could easily shift to moody and disgruntled.  If the water quality is not ideal and the space is limited or overcrowded, they may respond with aggression. Biting is one response to this.

Can You Train An Oscar Fish To Not Bite?

Although it’s possible to train fish, it’s best to start young and pick a species of fish that is intelligent. Thankfully, oscar fish are a good example of intuitive fish that some believe are willing to learn and can be trained to not bite.

It’s best to start early. Oscar fish grow rapidly in their first year. There teeth are softer in a juvenile state and they’re more adaptable in a new habitat. Be patient and slowly deliver the food to them with your hand.

You can start with rubber gloves or finger gloves on your thumb and index finger. This process will take time and further research is required to reach optimal levels of training with strategies and methods available to follow.

Don’t be frustrated if this doesn’t work. Each oscar fish is unique and may or may not take to training well.

Will Oscar Fish Bite Their Tankmates?

Oscar fish size up other fish in the tank and when they know they are one of the largest fish in your aquarium, they’ll flaunt it. They could get aggressive if any tankmates get in their way or try to battle them for space in the tank.

Avoid smaller fish that oscar fish could easily bully. Oscar fish swim in the middle or top of the tank, so it’s best to get fish that tend to swim at the bottom to avoid encounters that could turn aggressive. Oscar fish can nip at their fins and cause wounds or abrasion on your other fish.

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How Strong Is the Bite Of Oscar Fish?

Thankfully, oscar fish do not have powerful jaws. They are suction feeders who tear, bite, chew and spit out food to break it down for ingestion. They don’t smash or crush hard shells easily.

It will be hard for oscar fish to latch on to your finger, but it has happened before. Your finger will be saved in the end with minor cuts and some bleeding at the most. Your finger will not fall off. Oscar fish don’t have a strong enough bite.

How Do Oscar Fish Eat?

Oscar fish don’t eat like humans, sharks or piranhas. They are not trying to use their jaws or teeth in their mouth to bite and chew the food down to ingestible pieces. The teeth in their mouth are used to grasp on or catch the food.

The pharyngeal teeth in their throat is where the real action takes place. This is where they chew the food in their own way. Oscar fish are suction feeders so they need to suck the food in, then break it down further in their throat with a different set of teeth.

Are My Oscar Fish Biting Because The Tank Is Too Small?

A 55 gallon tank is debatably small for oscar fish. They are intelligent and large enough to demand for more space, decorations, rock and plants to keep themselves busy. They like to move rocks around and dig up the substrate or the plants.

Providing them with nothing to do in a smaller sized tank is a problem. The oscar fish may get bored, depressed or frustrated. This may make them more inclined to be aggressive when they see a hand or tankmates invading their space.

Keep your oscar fish in a 75 gallon tank or larger with suitable tankmates and plenty of room to swim around and things to manipulate so they will not be as likely to bite.

Is My Oscar Fish Biting Because It’s Sad?

An oscar fish that is uncomfortable or sad may enlarge its gills and open its mouth wider than usual. They may feel lonely or bored and opening their mouths wide may compare to the way we sigh and groan.

When their mouths open and gills gets larger, their head looks bigger too at this time. This is the wrong time to stick your hand in the tank or they may take a bite.


Oscar fish enjoy human companions interacting with them from time to time. They are fussy with water parameters, temperature and tank space. They need suitable tankmates who aren’t too small and don’t swim in their way.

Start early with oscar fish and feed them slowly. Some oscar fish will take to gentle stroking of the side of their body if you feel like interacting with them. Start with gloves and build a relationship that provides them comfort and space to live an enjoyable life.

Brian Arial

Brian Arial has kept fish for leisure and worked with fish stores for most of his life. He enjoys writing and caring for aquariums and ponds.