11 Freshwater Aquarium Sharks For Tanks of All Sizes

Before we dive too far into our list of freshwater aquarium sharks, let’s get this out of the way. Technically freshwater sharks are not sharks. They don’t bear any relationship to the sharks in the ocean, but that doesn’t mean they aren’t cool in their own right.

These freshwater “sharks” all possess a similar appearance to marine sharks though, and that’s how they’ve earned their names. So now that we’ve got that out of the way, let’s dive into ten of the most popular freshwater sharks you can get for your aquarium!

---

10 Types of Freshwater Aquarium Sharks

1. Rainbow Shark

Scientific Name: Epalzeohynchos frenatum

Size: 6 inches

Tank Size: 30 gallons

Care Level: Expert

Temperament: Aggressive

If you’re looking to add a freshwater aquarium sharks to your tank, the Rainbow Shark might be just what you need. They’re smaller sharks, which means you don’t need as big of a tank.

However, they’re an aggressive and extremely territorial fish, so if you plan to house more than one shark or other types of fish, ensure you have an extremely large aquarium. Despite their names, Rainbow Sharks aren’t the most colorful sharks out there either.

They have bright red fins paired with a blue-tinged body. Still, if you’re looking for sharks and don’t have a very large aquarium, Rainbow Sharks are the way to go.

2. Bala Shark

Scientific Name: Balantiocheiolos melanopterus

Size: 12 inches

Tank Size: 120 gallons

Care Level: Easy

Temperament: Peaceful

Just because it’s a shark doesn’t mean that it’s out there hunting down every fish they can get a hold of. The Bala Shark dispels this notion by being a great community fish.

However, they grow up to 12-inches in size, and you need to keep them in schools. You need at least four to six Bala Sharks to keep them happy and healthy, and that’s why you need a minimum of a 120-gallon tank to keep these 12-inch fish.

And if you’re looking to turn your tank into a true community tank, you’ll need to up it further from there. Think closer to a 200- or 250-gallon tank for a true community tank with Bala Sharks.

The good news is that they’re easy to care for, which makes them an excellent choice for beginners with a larger tank.

3. Red Tail Shark

Scientific Name: Epalzeohynchos bicolor

Size: 6 inches

Tank Size: 55 gallons

Care Level: Intermediate

Temperament: Semi-aggressive

While the Red Tail Shark isn’t so aggressive that they can’t be community fish, they’re aggressive enough that you need to pair them with something they can’t easily eat.

Like the Rainbow Shark, the Red Tail Shark stays smaller in size, but since they’re not overly aggressive, you can more easily pair them with other fish. In fact, while they enjoy chasing other fish around, they rarely bite and attack them.

A tank with plenty of hiding places is crucial if you plan on having a community of fish instead of a Red Tail Shark only tank.

These fish don’t have the most colorful appearance, but they can still add a nice flair to your tank. They have a bright red tail, while their bodies are a dark blue/black color.

4. Iridescent Shark

Scientific Name: Pangasianodon hypophthalmus

Size: 48 inches

Tank Size: 300 gallons

Care Level: Beginner

Temperament: Peaceful

If you’re looking for a massive shark and have a large enough aquarium for them, the Iridescent Shark is an outstanding choice. They grow to a whopping 48-inches, but despite their large size, they have an extremely peaceful and calm demeanor.

Of course, their larger size means they need a massive tank, and the minimum tank size for an Iridescent Shark is 300 gallons! And that’s for a single shark with no tank mates, and they’d certainly appreciate even more space.

Also, keep in mind that these fish prefer schools, which means you probably won’t have the space to care for them properly. Because of this, it’s probably a better choice to put them in a home pond. Otherwise, your home aquarium will likely stunt their growth and lead to them having a shorter lifespan.

5. Columbian Shark

Scientific Name: Ariopsis seemanni

Size: 10 to 14 inches

Tank Size: 75 gallons

Care Level: Easy

Temperament: Peaceful

The Columbian Shark is a nice cross between the massive Iridescent Shark and the smaller Red Tail Shark. If you give them enough space, these fish can reach 14 inches in size, which means you only need to house them in a more reasonable 75-gallon tank.

That tank size might seem a bit large, but just like with the Bala Shark, the Columbian Shark is a schooling fish. You need at least 3 Columbian Sharks to keep them happy, but five is really the recommended number.

With five Columbian Sharks, a 75-gallon tank is as small as you can go without potentially stunting their growth.

And while the Columbian Shark is a great community fish, if you’re looking for a true community tank, you’ll need to up the size even further, to about 100-gallons or more.

6. Harlequin Shark

Scientific Name: Ctenacis fehlmanni

Size: 12 inches

Tank Size: 55 gallons

Care Level: Expert

Temperament: Aggressive

While the Rainbow Shark might have the most colorful-sounding name, if you want a fish with tons of colors, then the Harlequin Shark is the way to go. Their typical colors are gold and black, but it’s not too rare to find them with orange hues either.

They reach an impressive 12-inches in length, but since they’re not schooling fish, that means you can comfortably house one in a 55-gallon aquarium. But just like with the Rainbow Shark, the Harlequin Shark is an extremely aggressive fish.

This means if you’re looking for a community tank, you’ll need to drastically up the size, and even then, you’re taking a risk. It takes an experienced hand to mix these fish with any other species, so if you’re a novice fish keeper, the Harlequin Shark might not be what you’re looking for.

The good news is that there are plenty of peaceful freshwater shark options to choose from still!

7. Violet Blushing Shark

Scientific Name: Labeo boga

Size: 12 inches

Tank Size: 55 gallons

Care Level: Easy

Temperament: Peaceful

The Violet Blushing Shark might not sound like the most impressive shark out there, but that doesn’t mean they wouldn’t make a great addition to your tank. They’re extremely peaceful, and they “only” reach 12 inches in size.

This means you only need a 55-gallon tank to comfortably house a school of three, and it really is best to school these fish as they do better that way. Still, they make excellent community fish, even if they are a tad bit territorial.

If you’re looking to add them to a community aquarium, go with a 100-gallon tank or larger, and try to keep the school of fish right at three.

Finally, in the wild the Violet Blushing Shark is critically endangered, so ensure you’re ethically sourcing these fish and not violating any local laws or ordinances when you get them.

8. Black Shark

Scientific Name: Labeo chrysophekadion

Size: 36 inches

Tank Size: 200 gallons

Care Level: Expert

Temperament: Aggressive

The Black Shark is another massive shark choice you have. But the good thing about that Black Shark is that their maximum size is a full 12 inches shorter than the Iridescent Shark, and they also don’t require a school.

This means that if you have a larger indoor aquarium, at least 200 gallons in size, there’s no reason you can’t add a black shark. But, if you’re looking to add any other type of fish, think again. 200-gallons is the bare minimum for these fish, and they’d really appreciate another 100 gallons or so.

So even if you get a 300-gallon tank, a single Black Shark is all you can get. Any other fish you add to the tank will likely just turn into shark food. But if you’re fine with a massive single fish tank, the Black Shark isn’t too complicated to care for.

But keep in mind that these fish can live up to ten years, and that’s a long time to devote a massive tank to a single fish.

9. Chinese High-Fin Banded Shark

Scientific Name: Myxocyprinus asiticus

Size: 53 inches

Tank Size 500 gallons

Care Level: Easy

Temperament: Peaceful

So you thought the Iridescent Shark and the Black Shark were big? They pale in comparison to the massive Chinese High-Fin Banded Shark. Coming in at 53-inches, these fish are truly massive. In fact, while we put the minimum tank size at 500-gallons to truly reach their full potential, 800-gallons is ideal.

Because of their massive size, we highly recommend adding them to a private home pond instead of an in-house aquarium. Even with a massive pond, it needs to be extremely large to allow them to really thrive.

The good news is that they’re peaceful fish, so if you do have enough space and decide to add some tank or pond mates, there’s no reason they can’t all live happily together.

10. Silver Apollo Shark

Scientific Name: Luciosoma spilopleura

Size: 10 inches

Tank Size: 55 gallons

Care Level: Easy

Temperament:  Peaceful

While the Silver Apollo Shark might be the last shark to make our list, it’s not because they’re the least desirable choice. They’re extremely easy to care for, and when you combine that with their 10-inch size, you can happily house them in a 55-gallon tank.

But like many of the smaller sharks, they’re a school fish that needs a community to thrive. Aim to keep at least six Silver Apollo Sharks together at all times, so a 55-gallon tank is really pushing it.

And if you’re looking for tank mates, you’re right back to needing a 100-gallon tank to keep everybody happy.

Finally, don’t expect the Silver Apollo Shark to look like much of a shark. Outside of their much larger size, they don’t look much different than a minnow. They’re not the most impressive looking, but their sheer size makes them a little more impressive.

There are probably cooler freshwater aquarium sharks out there, but you’ll be hard-pressed to find any that are easier to care for.

---

Setting Up Your Aquarium

Before you start adding any fish to your aquarium, you need to get everything set up properly. This all starts with getting the right sized aquarium, adding all the decorations, gravel, filters, and letting the bacterial functions cycle.

To do this humanely, you’ll need to complete a fishless aquarium cycle. It’s a pretty easy process, but a lot of people make it more complicated than it needs to be.

Add the tap water and treat it with a product like Safe Start to remove any chemicals in the water. But while the bottle says it’s now safe to add fish, don’t fall for it. You still need to get beneficial bacteria in the aquarium, or all your fish will die from ammonia poisoning.

To do this, simply add an ammonia product for fishless cycling and monitor the ammonia, nitrite, and nitrate levels. Once the nitrate levels spike and then level out, you’re safe to start adding fish. To get the nitrate levels back to normal after they spike you should complete a partial water change.

But keep in mind that you need to let the levels spike first. The concept behind all this is pretty simple. You add the ammonia and the bacteria that feed off the ammonia forms. This bacterium turns the ammonia into nitrites, and new bacteria forms to turn the nitrites into nitrates. You remove the nitrates through a water change.

When you add new fish, they create more ammonia, but since the bacteria is already there to convert it into nitrites, your fish stays healthy and happy, free of ammonia poisoning.

Finding Tank Mates

Finding the right tank mates for your freshwater shark is about more than just checking the temperament of each fish, although that’s where you should always start.

You also need to check the conditions that each fish lives in. They need to have overlapping zones of temperature, pH, and hardness before you even think of adding them together.

You also need to keep them similar in size. Because even a peaceful 12-inch fish will quickly gobble up a 1-inch fish, if it can fit it into its mouth. But as long as the fish are peaceful, about the same size, can live in the same conditions, and you have enough space for them, they should make good tank mates.

As a final consideration, you should look at what zones each fish hangs out in. Bottom feeders pair well with top swimmers, but this isn’t an absolute necessity.

Determining How Many Fish to Add

Determining how many fish to add is a pretty straightforward process, at least until you start adding tank mates. As a general rule of thumb, you should add no more than 1-inch of fish per gallon of water. So, for a 55-gallon tank, you can have up to 55 inches of fish.

Of course, this rule isn’t perfect, but it is a good starting point. Some things you need to consider when using this rule include the temperament of the fish and the overall size of a single fish.

Technically, by following this rule, you could try to add a single 55-inch fish to a 55-gallon tank. The problem with this though is that you should also have the overall length of your tank be twice as large as the largest fish. So, unless your 55-gallon tank is 110-inches long (it’s not), you’re still not good to go.

But if you’re looking to add 11 five-inch fish, you should be good to go. The second problem is that it doesn’t account for the temperament of the fish. Aggressive fish need more space.

Without this buffer zone in the tank, you’ll end up with dead fish even if you stay well within the 1-inch per gallon rule.

Meanwhile, going the other way, you can technically have a few extra inches of fish if they’re schooling fish. This is why the minimum tank size for six Silver Apollo Sharks is 55-gallons instead of 60. The fish all like to stay tightly packed together, so they don’t need a little extra space, although they’d certainly appreciate it.

Setting Up a Pond

If you’re looking into keeping a massive shark, but don’t have the space inside your home for it, then a pond might be the right way to go. Just keep in mind that ponds present their own challenges, and those challenges can get pretty expensive to keep up with.

For instance, the Chinese High-Fin Banded Shark can handle temperatures as low as 40 degrees, but in many Northern states that means you need to install a heater for your pond.

With an 800-gallon to a 1,000-gallon pond, installing a heater that can keep such a large pond warm is no easy task!

Another consideration you need to take into account when setting up your pond is that the cycles are the exact same as an aquarium. Before adding fish, you need to let the pond cycle, and you need to install proper filtration systems and set up UV lights to treat for algae growth.

This is all doable, but it’s no small task. In fact, compared to a much smaller aquarium inside, setting up a 1,000-gallon pond is much, much more challenging.

---

FAQ

If you have a few questions after reading through our guide of freshwater sharks, you’re not alone. That’s why we took the time to address some of the most frequently asked questions here.

What Sharks Can Be Kept in Aquariums?

As long as you have enough space and the appropriate conditions, you can keep just about any freshwater aquarium sharks in an aquarium. The key is that you have enough space, and that you don’t mix aggressive species with other fish.

It’s all about proper fishkeeping, and that’s true with freshwater sharks too!

What Do Freshwater Aquarium Sharks Eat?

freshwater aquarium sharks have a very similar appetite as other aquarium fish. Tropical flakes, spirulina flakes, granules, algae rounds, shrimp pellets, and the occasional feeder fish all make great choices for freshwater sharks.

Of course, always do your research for the particular fish you’re getting, before feeding them.

How Long Do Aquarium Sharks Live?

If you’re looking for a long-lasting fish, then aquarium sharks are an outstanding choice. Aquarium sharks can live anywhere from ten to twenty years, which means you’re not making a short-term investment in a fish.

Of course, this all is dependent on you properly caring for them. Keep in mind that once your sharks are full-grown, you’ll have a very hard time rehoming them, even if you want to.

What Is the Smallest Kind of Shark?

The smallest marine shark out there is the Dwarf Lantern Shark. Measuring just under 8 inches, it’s the smallest saltwater shark out there.

However, if you’re looking for the smallest freshwater shark, then both the Rainbow Shark and the Red Tail Shark are strong contenders. You’ll be hard-pressed to find a freshwater shark that’s smaller than six inches when full grown.

Are Freshwater Sharks Aggressive?

Like all fish, it really depends on the exact species. The Rainbow Shark is an aggressive freshwater shark, but the Silver Apollo Shark is extremely peaceful by comparison.

And it doesn’t have a thing to do with size, since the Rainbow Shark measures six inches and is aggressive, while the massive Chinese High-Fin Banded Shark measures 53-inches and is extremely peaceful.

---

Final Thoughts

There are few fish as cool to add to your aquarium as a shark. But keep these two things in mind when you’re thinking of adding a shark to your tank.

First, while these fish might bear a resemblance to the marine sharks in the ocean, they’re not at all related. Second, since these are larger fish, they all need larger aquariums to thrive in. Don’t try to push a shark into a tank that’s not big enough for them, no matter how bad you want a shark in your aquarium.