Are Glofish Sharks Aggressive? {Try This Now}

Are you wondering are GloFish shark aggressive towards tankmates?

What do you need in place to make sure your GloFish shark lives peacefully in a community tank?

In this article, we’ll find out if GloFish sharks are aggressive.

Are Glofish Sharks Aggressive?

GloFish sharks are considered semi-aggressive because of their territorial tendencies.

Give one enough room to enjoy bottom-dwelling on the aquarium floor and keep territorial tankmates who occupy similar spaces away from your GloFish shark.

What Is a Glofish Shark?

Glofish sharks are not actually carnivorous sharks, but a genetically engineered type of rainbow shark (Epalzeorhynchos frenatum) that enjoy freshwater aquariums.

They carry the following tendencies:

  • Territorial
  • Adaptable
  • Resilient
  • Hardy
  • Semi-aggressive
  • Live around 4-6 years
  • Grow an average of 4 inches
  • Enjoy tank sizes over 20 gallons
  • Prefer to be kept away from other GloFish sharks

Your GloFish shark doesn’t want to share the bottom of the tank with similar sized tankmates or its same species.

You will need a tank size of 50-100 gallons if you plan on keeping more than one GloFish shark.

Why Are Glofish Sharks Aggressive?

GloFish sharks are considered semi-aggressive because they take on the same behavioral tendencies as rainbow sharks. They’re hostile towards each other and do not tend to breed well in captivity.

What makes them a shark is that they prefer to be kept alone and claim territories. They’re known to nip and bite at any aquatic life who gets near or tries to invade its space.

You will have to surrender the entire bottom of the aquarium floor for your GloFish shark. Stock your community tank with middle or top-level swimmers as suitable tankmates.

Can I Keep a Glofish Shark With Other Glofish?

Yes. Make sure to keep only one GloFish shock per aquarium unless you have a tank that is larger than 50 gallons.

It’s best to keep a GloFish shark with the following types of GloFish:

  • Tetras
  • Danios
  • Barbs
  • Bettas

Please keep GloFish barbs in groups of five or more to prevent aggression with your GloFish shark.

GloFish Bettas are also territorial, but if your tank is larger than 30+ gallons, they’ll swim at the surface and keep their distance from your GloFish shark.

YouTube video

Do GloFish Sharks Bite?

Since GloFish sharks are known to be semi aggressive, they may express it in the following ways:

  • Chasing
  • Biting
  • Intimidating

The hostility will quickly turn to aggression if a Glofish shark feels that any community tank member is encroaching on its territory.

Keep the tank spacious, full of hiding spaces and reserve the bottom floor of the aquarium for a single GloFish shark to remain peaceful.

Do GloFish Sharks Get Along?

No. GloFish sharks do not tend to get along with each other because they are sharing the same space in the bottom level of your tank.

Although the minimum tank requirement for keeping one GloFish shark is 20 gallons, when adding more than one of the same species you will need more than double the space.

Consider tank dividers, plenty of hiding spaces and a long tank that is 50 gallons or larger if you wish to keep more than one GloFish shark.

What Fish Can Live With Glofish Sharks?

Any fish that is not a bottom dweller who doesn’t wish to invade the substrate territory of your GloFish shark should be safe.

If your middle to top level swimmer is not intimidated easily, they won’t feel stress from this hostility and could hold their own when a GloFish shark enters their spaces.

A shy or timid fish will back away, hide, sulk and possibly give up eating if they are bullied by your GloFish shark.

Here are the tankmates we recommend in spacious tanks where only one GloFish shark remains on the bottom:

  • Rainbowfish
  • Danios
  • Barbs
  • Gouramis
  • Rasboras
  • Cichlids

GloFish sharks will attempt to eradicate smaller nuisance snails from the substrate and clean up algae if they are left alone at the bottom of the tank.

What Do GloFish Sharks Eat?

GloFish sharks are not carnivores like great white sharks in the wild. They are not interested in consuming only meat and bones.

GloFish sharks are not picky eaters and will eat almost any variety of food that you present to it. You will also benefit from a GloFish shark eating algae from the bottom of the tank.

Offer the following foods:

  • algae tablets, wafers and flakes
  • insect larvae
  • tubifex worms
  • periphyton
  • crustaceans
  • phytoplankton
  • zooplankton
  • aquatic insects
  • lettuce
  • spinach
  • shrimp pellets
  • blended flakes and pellets

Can GloFish Tetras And GloFish Sharks Live Together?

GloFish tetras are the least recommended variety of GloFish to live together with GloFish sharks.

GloFish tetras are smaller in size and a juvenile could be consumed with one gulp if it invades the territory of a GloFish shark.

Keep your GloFish tetras in a school and encourage them to swim in the middle of your tank with plenty of hiding spaces.

If curiosity strikes when one of your GloFish tetras tries to swim at the bottom of the tank, it may become the next meal for your GloFish shark or become badly injured.


GloFish sharks are a welcome addition to a community tank as long as you keep one only to dwell on the aquarium floor. They are hardy and great for beginner hobbyists if you keep them away from other bottom dwellers.

Enjoy building decorative hiding spaces and planted areas for the rest of your community fish to keep their distance as they enjoy the middle or top levels of the tank.

Your GloFish shark, much like a rainbow shark, will help you out by nibbling on algae, but would appreciate a wide variety of meals that you offer as well.


Thanks for visiting for another article dedicated to GloFish that we research and keep. Our kids love them as well. See you soon for another article anytime you feel curious for more information. Bye for now!

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.