How Hard Is It to Keep an Octopus in an Aquarium?

Keeping fish, crabs, shrimp, or other sea creatures in an aquarium can be pleasant and rather effortless once you have the system under control.

However, with an octopus, you kick the difficulty up a notch and introduce a new layer of challenges to the aquarium. Suffice to say; keeping an octopus in an aquarium not easy.

These intelligent sea animals don’t have the same needs as the everyday aquarium fish. They require special care that novice fish keepers might overlook.

Nonetheless, octopuses are rewarding to keep and have a fascinating personality unlike any other. Plus, they’re super fun to observe!

Octopus keeping doesn’t have to be hard. Let’s explore the ocean depths of keeping an octopus safe and happy in the aquarium.

The Aquarium: Conditions, Temperatures, and Habitat

Octopuses are naturally solitary creatures, so they fare well in isolated tanks in the right environment.

These are the conditions that your aquarium should ideally meet for your octopus keeping needs:

  • A sealed lid to prevent an imbalance
  • A salinity between 1.022 – 1.023
  • pH values of 8.2 with sufficient oxygen flow
  • 76-78 degrees Fahrenheit
  • For one octopus, at least 55 gallons of water

Outside the aquarium, keep your octopus in a dimly lit environment. Don’t put them in a room that has exposure to direct sunlight. During the day, use dim light from a low wattage fluorescent tube; and at night, turn off any light source that may irritate your octopus.

As for the aquarium base, it’s a good idea to replicate the octopus’s natural habitat. They like to live along coral reefs near the ocean bottom — and they tend to dig holes to hide and protect themselves from predators.

Sufficient oxygen, good water quality, and enough resources are crucial to making your octopus feel at home. Many species of octopus live for only 1-2 years, so be on your toes if something about your aquarium is off.

Recreate your tank’s bottom layer to look like an octopuses’ haven. Add some fine layers of sand, put a live rock or two in it, and try to position them to serve as hiding spots. Ideally, they’d like this to face away from the light — so keep that in mind as you decorate your tank!

The Octopus: Behavior and Personality in the Aquarium

An octopus’s intelligence is one of its most admirable and finicky traits, so keeping them as pets requires more care than low-maintenance animals.

To put it into perspective, one-third of the octopus’s neurons are found in its brain. So by an invertebrate’s standards, they’re very smart and perceptive creatures.

For instance, octopuses are capable of vertebrate-like spatial learning and pattern and shape recognition. They’re also capable of play, which is something only intelligent animals do.

How Does an Octopus Behave?

Octopus behavior is unique among other cephalopods. Here are two examples of their capabilities in action.

A few years back, a couple of scientists performed an experiment with captive octopuses in the Seattle Aquarium. There, they left an octopus in an empty tank with only a pill bottle. Nothing noteworthy happened at first, but after the fourth time, the octopuses started to play with the bottle.

Here’s how they played: They blew a strong current of water to the pill bottle, causing it to go over a water jet in a tank and return to the octopus. They repeated this sequence for over 20 times, similar to how humans would bounce a ball!

Here’s another story.

A researcher left a floating thermometer on the aquarium intending to measure the water temperature. Not more than five minutes later, the octopus in the aquarium latched itself onto the object and started dismembering it, piece by piece.

The examples above flesh out what to expect when you keep an octopus. So be on your guard — and don’t make the mistake of leaving behind metal objects and random trinkets floating in the tank.

Will the Octopus Be an Interesting Pet Under Captivity?

Given their intelligence, these creatures understand their captivity within the tank. As such, when unsatisfied, they might utilize their shape-shifting abilities to become master escape artists when they feel like it.

With many shape-shifting and color-changing octopuses around, you can expect them to morph and impersonate the things they see.

Whether it’s rock, seaweed, or sea creatures — an octopus can change into the color of its surroundings and camouflage itself in threat of danger.

What Are the Challenges of Keeping an Octopus?

I am sure you already know that octopus is not something aquarium enthusiasts plan to keep in their tank. If you’re a new aquarium owner with no prior experience, I would suggest so with some easy-to-care fish such as Gold Fish or Betta.

Aside from the unpredictable behavior of octopus and the short lifespan of 1-2 years, there are other things to keep in mind when keeping an octopus in a tank.

Octopus Diet is Expensive

The first thing you have to consider when keeping an octopus is its expensive diet. They tend to enjoy eating live food, such as shrimp and crab.

While they prefer crustaceans, an octopus also isn’t against eating fish swimming around their sanctuary. So a keeper should separate their pet octopus away from the other live pets lest it will eat them.

The Octopus Might Escape

Hiding under the sandbed or artificial crevices isn’t the only way an octopus can rebel inside the aquarium.

Octopuses can escape the home aquarium if their keeper isn’t vigilant. They’re masters in fleeing through tight ventilation tubes and pushing past the sealed home aquarium.

This is why having a great aquarium is of utmost importance when keeping an octopus.

Legal and Ethical Issues

Many scientists also worry about keeping such an intelligent creature in captivity for their short life. Not only that, but the allure of owning octopuses, such as the venomous blue-ringed octopus, might unnecessarily expose naive hobbyists to the dangers of certain breeds.

In addition to this, the Convention on International Trade in Endangered Species of Fauna and Flora (CITES), which regulates cross-border wildlife trade, doesn’t list any octopus species under its authority.

This makes it slightly more legally questionable to keep an octopus compared to other forms of marine life.

It’s your responsibility to check whether your area allows you to possess exotic pets.

What Octopuses Are Fit for Aquarium Living?

With over 300 octopuses known to exist, there are some that are more suitable to keep in a tank than others.

Octopus in an Aquarium

The octopus you keep will affect the difficulty curve you’ll face with your new pet – so bear that in mind!

The Good

The California Two-spot Octopus is a popular pet octopus option for many octopus enthusiasts.

It’s an exotic octopus that fares well in an enclosed tank, needing about 50 gallons or more.

They’re also friendly in nature, so they’re a lot less high-maintenance compared to other octopus species.

The Meh

The mimic octopus captures many people’s interest in its color-changing abilities. However, that’s the extent of the pros of keeping that breed as a pet.

They require heavy water maintenance, have a fine salt sensitivity, and need a heated tank and very deep sand bed.

Plus, they’re already facing endangerment due to habitat destruction. If you’re still starting out, another octopus besides the mimic will be a better experience.

Other articles you may also like: