How Many Lionfish Can Be In One Tank? {4 Major Factors}

Will Lionfish fight, play or avoid each other? How many Lionfish can be in one tank?

In this article, we’ll discuss the amount of Lionfish that can be kept together in one tank.

How Many Lionfish Can Be In One Tank?

The answer is not as simple as 2-4 in 30-55 gallons tanks. How many Lionfish you can keep together depends on:

  1. tank size
  2. number of hiding spaces
  3. male to female ratio
  4. age and size of each Lionfish

They are known to hunt together in the wild, but ensure that you stock more females to males or that they are all the same size. Let them grow up together and be weary of mixing different types of Lionfish together.

How Big Should My Tank Be For Multiple Lionfish?

When considering the multiple types of Lionfish that are available for hobbyists, we have to look at dwarf sized Lionfish separately from medium to large sizes of Lionfish.

You should start with a 30 gallon tank for 1-3 dwarf Lionfish, but 50 gallons would be better. Try to stock one male to two females if you can to reduce any chance of aggression.

2-4 Dwarf Lionfish (up to 8 inches in length)

30-55 gallons

2 or more Medium Sized Lionfish like Antennata or Devil (Up to 10 inches)

55 gallons or more

2 or more Large Sized Lionfish like Russell’s or Volitans (10-16 inches)

75 gallons or more

Medium to large size adult Lionfish will need plenty of room in a 75 gallon or larger tank. They need their own hiding spaces and will remain sedentary throughout most of the day until it’s time to eat.

Are Lionfish Aggressive?

Sometimes. Lionfish tend to be docile and keep to themselves. They are aggressive under these conditions:

  • Hunting for anything that fits into their mouth
  • Not enough room in the tank
  • Not enough hiding spaces
  • Being bullied (self defense)
  • Being larger than another Lionfish

Do not keep dwarf Lionfish with full sized Lionfish to avoid the larger one attempting to gobble up its counterpart. Make sure there is enough space and hiding spots in the shade for each of them to call their home.

Tankmates are tricky, but if they are fast swimmers and large enough, you may consider stocking Triggerfish, Tuskfish or plenty of other reef fish if you desire.

How Many Volitans Lionfish Can I Keep Together?

Volitans in the wild travel in groups of 4 or more. They are the most popular centerpiece Lionfish commonly found in aquariums. A 2 inch juvenile will grow up to 10 inches in about a year.

You will find Volitans Lionfish hiding safely in shaded spots during the better part of the day.

At an average maximum length of 15 inches in captivity, you will need a tank with enough room for them to turn around.

  • 18 inches of tank width holding 85 or more gallons of water for 2-3 Volitans Lionfish together.

Add up to 4 or more if your tank is larger than 100 gallons and you have separate hiding spaces for each one. Make sure they grow up together at the same size. A larger Volitans could try to eat any other Lionfish or tankmate that is half its size.

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Will Lionfish Eat Each Other?

Yes. Lionfish are generalists who will hunt and eat anything they can fit into their mouths. A dwarf Lionfish can and will be eaten by a larger member of the Lionfish family.

Two or more Lionfish of the same size will not be a threat or considered as food. They will allow each other the space as long as your tank size and hiding spots that create comfort and shade are ample and spaciously available.

Dwarf Fuzzy Lionfish and Dwarf Zebra Lionfish have been known to fight each other for space in smaller tanks. You may witness:

  • gill cover flaring
  • chasing
  • biting
  • head shaking

Separate them if one is smaller than the other or if your tank is not large enough to house multiple Lionfish.

How Can You Tell A Male and Female Lionfish Apart?

Male/female pairs work well if you keep more than one Lionfish. If you keep 3 or more, try to outnumber the males 2:1 with more females to reduce any chance of aggression.

Lionfish need to more mature before being able to identify their gender. Wait until they are about 4-5 inches at least. Males tend to have:

  • a squared head
  • longer pectoral fins
  • more rings on their pectoral fins
  • broader body

A peaceful group of Lionfish will remain that way if you give them a better chance to live in separate spaces. This requires you to have a tank larger than 75-85 gallons for full sized Lionfish.

How Many Lionfish Can You Have In A Tank?

Dwarf Fuzzy Lionfish tend to live peacefully in larger groups of 3-10. The only way to keep as many as 10 dwarf sized Lionfish is to have a tank size of 100 gallons or greater.

It’s best to keep more females than males to ease dominance and aggression. They should not attack each other or try to eat one another if they are the same size.

Common Lionfish Tank Requirements

1. Fu Man Chu Lionfish

  • Dendrochirus biocellatus
  • Size: 5-6 inches
  • Tank Size: 30 gallons+

2. Dwarf Fuzzy Lionfish

  • Dendrochirus brachypterus
  • Size: 7-8 inches
  • Tank Size: 30 gallons+

3. Dwarf Zebra Lionfish

  • Dendrochirus zebra
  • Size: 6-8 inches
  • Tank Size: 30 gallons+

4. Antennata Lionfish, Spot-finned Lionfish

  • Pterois antennata
  • Size: 8-9 inches
  • Tank Size: 55 gallons+

5. Devil Lionfish, Mombassa Lion, Deepwater Lionfish

  • Pterois mombasae
  • Size: 7-8 inches
  • Tank Size: 55 gallons+

6. Radiated Lion, Clearfin Lion

  • Pterois radiata
  • Size: 9-10 inches
  • Tank Size: 65 gallons+

7. Russell’s Lionfish

  • Pterois russelli
  • Size: 10-12 inches
  • Tank Size: 75 gallons+

8. Volitans Lionfish

  • Pterois volitans
  • Size: 12-15 inches
  • Tank size: 85 gallons+

What Fish Live With a Lionfish?

Lionfish tankmates in suitable tank sizes include:

  • rock beauty angelfish
  • threadfin butterflyfish
  • Foxface rabbitfish
  • blue tang
  • maroon clownfish
  • snowflake moray eel
  • harlequin tusk fish
  • anglerfish
  • panther grouper
  • clown triggerfish

Hiding spaces and other water parameter issues need effort and execution to manage an ecosystem with these fish together.


Please keep in mind that Lionfish are not a great fit in your community tank. They may allow a tankmate to exist for weeks or months and suddenly, they get snatched and eaten in the blink of an eye.

Keep Lionfish of the same size together and think about getting the largest tank possible to allow them the comfort and space to hide or rest in shaded locations throughout the day.


Thanks for visiting for another article on Lionfish that we greatly enjoy taking care of in our aquariums. Check out more of our articles on the variety of marine and aquatic life we research and keep. 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.