Black Scorpionfish – Species Profile & Care Guide

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The Black Scorpionfish is one of the scariest-looking tank fish you can get. The fish’s appearance is one of the main reasons for its increased popularity among aquarists, along with its hunting behavior and overall personality.

If you’ve determined you need a Black Scorpionfish, a word of advice – avoid it if you’re a novice hobbyist.

This species is a bit more difficult to maintain, especially if you lack the necessary know-how.

And, even if you do, many things can go wrong when keeping a Scorpionfish, as we will soon see.

Black Scorpionfish Requirements

To understand what this fish needs in terms of environmental setup and water parameters, consider the following:

  • Black Scorpionfish are ambush predators who like to bury themselves in the substrate or stick to reef structures while waiting for the prey
  • They can span up to 15 inches in size, but the average size is somewhere around 6-8
  • Since they lay motionless much of the day, Scorpionfish don’t need too much space

Knowing these aspects, you can now set up the Black Scorpionfish’s environment properly by managing its:

Tank size

The fish’s size will inform the necessary space. The Black Scorpionfish can grow up to 15 inches, but that’s fairly rare.

For the most part, you should expect your Scorpionfish to reach 7-8 inches on average.

The necessary water volume differs based on the fish’s size, but it shouldn’t put too much strain on your pockets.

As an ambush predator, the Scorpionfish isn’t too active, to begin with. Consider at least 25 gallons of water for a smaller specimen in the neighborhood of 6 inches.

Larger specimens may require more space, up to 75 gallons for a 15-inch Scorpionfish.

You should consider a similar tank size in case you decide to have several smaller Scorpionfish. Provided you have the adequate tank layout, of course.

Scorpionfish are pretty aggressive and territorial, despite not requiring much space. The space they occupy, however, almost always bears the markers of an ambush spot.

Scorpionfish will select their ambushing location based on position in relation to the prey’s roaming areas. It’s understandable why they would fight over space.

Water Parameters

As a marine fish, the Black Scorpionfish enjoys warmer waters in the neighborhood of 73 to 81 F with a pH of 8.1 to 8.4.

At this point, we have to mention that the Scorpionfish is probably one of the hardest when it comes to fluctuating water parameters and diseases.

This fish has a well-developed immune system, rendering it almost impervious to a variety of disorders.

However, don’t let yourself be charmed by the Scorpionfish’s genetic prowess.

Unstable water parameters will hurt the fish eventually, causing stress and increasing its aggressiveness.

The fish requires a robust and reliable filtration system, a heater, and regular tank maintenance, including weekly water changes.

This is that much more necessary considering the presence of a coral system, which the Scorpionfish almost demands to thrive.


I recommend sand, given the Black Scorpionfish’s tendency to bury itself in the substrate.

Sand will replicate the Scorpionfish’s natural habitat and allow the predator to feel more comfortable in its environment.

Sand is also easy to clean since it prevents fish waste, dead organic matter, and food leftovers from sinking in. The main problem with sand is the risk of anaerobic buildup.

To put it simply, sand doesn’t allow water to flow through it. If the water can’t flow through, oxygen can flow through it either.

This is an issue since the tank’s beneficial biome comprises microorganisms that consume oxygen. The ones that don’t are the bad ones, and these are the ones that will thrive inside a sandy substrate.

These bacteria will produce ammonia as a byproduct after consuming the dead matter reaching their way.

Since ammonia is trapped underneath the substrate, it will form anaerobic pockets filled with this poisonous chemical.

Now, combine this worrying fact with the Scorpionfish’s tendency to bury itself in the substrate, and you can see the problem.

The fish will burst the pocket, releasing concentrated ammonia into the water. The chemical will alter the water’s chemistry so brutally and suddenly that it may send the fish into ammonia shock.

The solution is simpler than it seems. Simply vacuum the substrate regularly, at least once every other week, to prevent that.

Gravel isn’t a better option, since it comes with a choking hazard. The fish may swallow some larger particles by mistake and choke to death.

Gravel is more fitting for mid-to-top dwellers that have no interest in the substrate, to begin with.

Vegetation & Corals

The Black Scorpionfish doesn’t mind whether it has any vegetation or not. The plants’ presence is useful for aesthetic purposes and for improving the tank’s oxygenation.

The Scorpionfish won’t eat them since it’s a carnivorous fish, and it doesn’t risk breaking them since it doesn’t move much.

However, it can unearth them due to its predilection for burying itself in the substrate.

This is why you should either stick to floating plants or choose species that can withstand the Scorpionfish’s burying behavior.


A filter, a heater, and a water pump. These are necessary in a Scorpionfish tank to provide the fish with a stable, clean, and healthy environment.

Fortunately, the Scorpionfish doesn’t produce too much waste since it has a slower metabolism and eats rarer than other fish.

But it will dirty the tank water due to its hunting and feeding habits.

Mechanical filtration is paramount for Scorpionfish due to their tendency to bury themselves in the substrate and fill the water with floating particles.

Biological and chemical filtration are also vital, as they cleanse the water of dangerous chemicals and heavy metals.

The same goes for any water parameter that’s essential to the fish’s survival. Here, we include temperature, salinity, pH, and other vital aspects.

Black Scorpionfish Feeding and Diet

The Black Scorpionfish is a carnivorous predator that will stalk and kill everything swimming around it.

This includes smaller fish and crustaceans unfortunate enough not to realize the presence of the Scorpionfish.

Fortunately, they will experience a swift end since the Scorpionfish doesn’t like to play with its food too much.

When it comes to feeding the fish in captivity, pretty much anything goes with the Black Scorpionfish, so long as you cater to its predatorial instincts.

While this fish has adapted to life in captivity pretty well, it still has difficulties feeding properly. Fortunately, this problem falls more on the fish’s keepers than the fish itself.

It’s not always easy to provide your Scorpionfish with live food so that it can hunt it. Sometimes, you just have to feed it some frozen live food that’s typically not as lively as the real thing.

The problem is that the Scorpionfish will only eat food that it perceives as prey.

To stimulate its hunting behavior, you may want to wiggle the food in its face for a while. Just make sure you don’t use your hand.

The Black Scorpionfish isn’t smart enough to distinguish between legitimate prey and your fingers. Also, if it does, it may view your hand as a threat and sting you as a result.

Since the Scorpionfish is venomous, the result is almost always unpleasant. It won’t kill you, but the venom is powerful enough to cause discomfort and localized pain and swelling.

Black Scorpionfish Tank Mates

Finding reliable tank mates for your Scorpionfish can be quite a problem. This fish will eat most smaller fish species and doesn’t get along with any other larger ones.

The Black Scorpionfish is territorial and displays a pretty conspirative behavior. It doesn’t like to make friends and sees other fish as either prey or predators.

So, you should always consider the risk of your Scorpionfish attacking any fish coming near its hunting ground.

And this is a problem when considering the Scorpionfish’s spiky and venomous fin spears. 

They also don’t have a too well-developed social temperament. That being said, the Black Scorpionfish can tolerate the presence of others of its kind.

Just make sure you provide your Scorpionfish with enough space to mitigate territorial tendencies and food competition.

If you do want to pair the Scorpionfish with other specimens, make sure you find fish that:

  • Are at least 10 inches in size so that the Scorpionfish won’t see them as food
  • Prefer mid-to-top areas and will rarely move toward the substrate
  • Aren’t overly inquisitive to prevent them from bothering the Scorpionfish too much
  • Can handle themselves if and when attacked by the Scorpionfish
  • Won’t compete with Scorpionfish for food too much

Some compatible tank mates include the lionfish, squirrelfish, other Scorpionfish, etc. The latter mention is of particular importance, considering that the Scorpionfish is a slow eater.

Pairing them with fast and energetic eaters that share the same dietary preferences isn’t a good idea.

Black Scorpionfish Diseases and Treatment

The Scorpionfish isn’t sensitive to any fish disorder in particular. That being said, it can fall sick under certain conditions.

These include chemical poisoning via ammonia, chlorine, or heavy metals due to contaminated food. Or parasitic and bacterial infections resulting due to poor water conditions.

To keep your Black Scorpionfish healthy and prevent any disorders, I recommend:

  • Getting the fish from a reputable source – I only recommend buying your fish from fish shops if you don’t really care about its health. If you do, avoid fish shops. These places couldn’t care less about the conditions the fish lives in, so long as it remains alive long enough for them to sell it. This means there’s a high chance that you will get an already sick fish or, at best, one with a compromised immune system. Always get your Scorpionfish from trustworthy sellers, preferably with a reputation in the field.
  • Ensure optimal diet – The Black Scorpionfish will only eat 3-4 times per week. That’s because the fish has a slow metabolism and needs more time to digest the food. Despite eating rarer than other fish, the Scorpionfish still requires some diversity in its diet. Make sure your Scorpionfish receives a nutritious and stable diet to prevent vitamin and mineral deficiencies. These can be deadly in some cases.
  • Prevent food and water pollution – Several things can cause water pollution, such as cleaning the tank equipment with various chemicals that could kill the fish. Or using tap water to perform water changes and poisoning the environment with chlorine. When it comes to food, most problems occur when feeding the Scorpionfish wild-caught fish or crustaceans. These are often gateways for a variety of parasites and bacteria that could infect and kill your Scorpionfish. They may also contain harmful chemicals due to living in heavily polluted environments. Instead, consider keeping feeder tanks to provide your Scorpionfish with an unlimited source of fresh and healthy food.
  • Ensure optimal water parameters – The Scorpionfish demands clean and stable water parameters, especially since it will share its space with a thriving coral system (ideally.) Have a good filtration system installed and perform regular aquarium maintenance work to keep water conditions stable. And make sure that the filter doesn’t cause too much water flow that could damage the corals and cause discomfort to your Scorpionfish.
  • Prevent stress – There aren’t too many things that will stress your Scorpionfish since this creature likes to keep to itself. That being said, the fish can become stressed if the temperature fluctuates too much or water conditions are subpar. Monitor your fish’s habitat regularly to make sure everything remains within the charts.

If the fish gets sick despite all your efforts, you need to ensure immediate diagnosis and treatment. The main problem here is that diagnosing your fish’s condition may be more difficult than with other fish.

For instance, you can’t really tell if your Scorpionfish is irritated, lethargic, or experiences discomfort because the fish doesn’t move much anyway.

The most relevant indicator that something’s not right is the color change. Sick Scorpionfish may lose their coloring and even refuse food, even after not eating for a couple of days.

When that happens, I suggest assessing the fish’s state and quarantining it if you’re unsure what’s causing the problem.

Assess the water parameters for any parameter fluctuations and look for signs of ammonia, nitrite, chlorine, or any other chemical that may be responsible. The treatment will vary in duration and specifics depending on the disorder’s profile.

Black Scorpionfish are pretty hardy, so they will recover fast with proper care.

Provide the fish with a pristine environment, a nutritious diet, and antibiotic medication in case of parasites or bacterial infections.

You may also want to discuss the Scorpionfish’s problem with a specialized professional to make sure you’re doing everything right.

How Big do Black Scorpionfish Get?

Black Scorpionfish will grow up to 15 inches in captivity, although there are claims of 20-inch Scorpionfish in some cases.

However, a more realistic size range is 6-8 inches for a well-nourished Scorpionfish.

You can increase your fish’s size and growth rate a bit by:

  • Providing it with a nutritious and varied diet
  • Keeping its water parameters stable and within the optimal range
  • Provide the fish with a natural-looking habitat layout comprising a sandy substrate and rocky hiding areas
  • Keep the fish safe from stress and aggressive or inquisitive tank, mates
  • Upgrade your tank’s size to provide more room for your fish to grow properly

If despite everything, your Scorpionfish remains relatively small, it’s okay. It means it has reached its potential.

Don’t worry about it and enjoy its company while it lasts.

How Long do Black Scorpionfish Live?

A healthy Black Scorpionfish can live up to 15 years in captivity. This is an impressive lifespan compared to most tank fish that will barely reach half that.

To increase your Scorpionfish’s lifespan, consider all the points I’ve already mentioned in the previous segment.

Are Black Scorpionfish Aggressive?

Yes, they are. Scorpionfish are solitary creatures that will spend most of their lives camouflaged near the substrate.

They don’t have the inclination to socialize with other fish, except when they’re getting ready to eat them, and won’t leave their spot too often.

They are territorial and will snap at any fish disturbing their peace and wandering in their area.

So, be careful when you’re adding new fish to your Scorpionfish tank. The Black Scorpionfish is venomous and will use its venom-filled spikes to assert its dominance and inform other fish of its presence.

Oh, and try not to pet it. The Black Scorpionfish has no patience for human shenanigans and will sting you in a heartbeat. The venom won’t kill you, but it won’t be too pleasant either.

Are Black Scorpionfish Good for Beginners?

I would place the Black Scorpionfish in the Moderate care level category. This fish isn’t difficult to care for because it doesn’t have too many requirements.

It doesn’t produce too much waste since it only eats every couple of days, it doesn’t move much, and it doesn’t need too much space.

Caring for this species isn’t too different from caring for any other, I would say. Avoid the fish if you’re a complete beginner, though, because you might not be used to its aggression.

The fish also requires a reef tank with plenty of hiding areas and a rich, rocky environment. These tank setups are more difficult to maintain in the long run.


The Black Scorpionfish is a unique-looking specimen that I would recommend to anyone in search of a stealth predator.

The fish is mostly calm when kept alone, so it won’t disturb the aquatic environment too much. It’s the perfect choice if you’re into aquascaping and looking for a model to pose for you.

As a final note, since I almost forgot, don’t try to breed the Scorpionfish. There are no records of anyone successfully breeding this species in captivity.

Author Image Fabian
I’m Fabian, aquarium fish breeder and founder of this website. I’ve been keeping fish, since I was a kid. On this blog, I share a lot of information about the aquarium hobby and various fish species that I like. Please leave a comment if you have any question.
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