10 of The Best Freshwater Sharks for Your Home Aquarium

Freshwater aquarium sharks are stunning tropical fish present in all aquarium stores around the world. Despite the name, they are not real sharks. They earned the nickname because they have characteristics resembling the marine predators we all know. 

Many aquarists buy these animals without knowing their needs and habits, resulting in some issues. 

They are temperamental fish with needs that not all aquarists can provide. Some types can be aggressive and easily overgrow a tank. Nevertheless, freshwater sharks can be a beautiful addition to your aquarium as long as you can provide the right environment for them.

In this article, we will talk about 10 species of freshwater sharks and the general characteristics and general care of these graceful fish.

What is a Freshwater Aquarium Shark?

The so-called ornamental freshwater sharks refer to several species of fish. These species are distributed among different genera and families, such as some catfish and even barbs.

Despite being called sharks, these fish are not related to the famous saltwater sharks. They are called this way because of some similarities with these saltwater carnivores.

Just like sharks, freshwater sharks have elongated bodies, large fins, and long heads. They are always active and swim gracefully like true sharks.

I’ve already witnessed some aquarists saying that these freshwater fish are called sharks because they are fearless and aggressive predators, which doesn’t make much sense. Some species show aggressive behaviour (mainly territorial) and are large and even predatory, but this is not true for all.

Keep calm, you can easily perform aquarium maintenance without losing a finger!

Tank Size for Freshwater Sharks

Most species of freshwater sharks reach sizes considered large. Some of them become giants (just like Iridescent Sharks). They can get so big that we will hardly have any aquarium in our house that fits them.

A common point between the different species is that all species have very active behaviour. And even the smallest reach considerable size. Mainly because of these factors, we must provide these fish with a high-volume tank, so they will develop healthily.

In addition to the physical need for wide open spaces to swim, some species can be temperamental, territorial, and aggressive. This aggression increases even more when kept in less-than-ideal spaces.

An important point is to emphasize that we should never get these sharks, or any other animal, impulsively. The right thing is to always research the ideal requirements to keep the species we want. Each shark species has specific needs regarding tank volume, water parameters, and general care.

Freshwater sharks are fish that live for many years. When obtaining one of these animals, we have to ensure that as long as the animal lives, we will have conditions to provide everything they need, guaranteeing the maximum quality of life.

When considering the ideal aquarium size, keep in mind that the greater the volume of water available, the better the development of the fish will be. That’s a rule in the aquarium hobby.

The smallest shark species can be kept in aquariums above 70 gallons (265 litres). Even for these smaller sharks, I recommend aquariums over 120 gallons (454 litres). This volume is enough to adequately maintain them in healthy community aquariums.

Giant tanks bring giant responsibilities (and a heavy workload). The larger the aquarium, the greater the volume of water to be changed and the space to be cleaned. A large volume also requires adequate equipment, which means more investment and more significant availability of physical space.

Water Parameters

In addition to the size of the tank, the water must contain ideal parameters for the species that inhabit it. Parameters such as ammonia level, pH, and temperature must be kept stable and always within the ideal. 

Because it comprises several species, there is no single water parameter to cover all aquarium sharks: each type has specific needs.

All shark species are tropical fish, meaning they inhabit waters with warm temperatures ranging from 75 to 82 F (24 to 28ºC).

The vast majority of these fish are very hardy. Sharks can inhabit waters with different pH parameters, ranging from acid (6) to alkaline (8), as pH is linked to hardness. Some species inhabit waters ranging from soft (like some Asian species) to hard water (African ones).

Periodic Maintenance

Aquariums are closed systems. It is up to us to maintain the good health and hygiene of our tanks through periodic maintenance. Maintenance is the only way to keep the parameters stable and within the ideal range.

Basic aquarium maintenance involves siphoning the substrate, changing the water, and cleaning the glass and the decorations. These must be done weekly. 

Deep maintenance can be performed monthly and involves cleaning the filtration system, hoses, pumps, and all other equipment.

In the case of planted aquariums, maintenance of the plants is necessary. It’s something simple and quick to do during weekly maintenance. We must remove dead and fallen leaves; it is also the perfect time for pruning and replanting.

Cleaning the tank and removing debris is essential. Feces, dead plant parts, and leftover food will rot over time, polluting the water. That’s why the maintenance and replacement of water are vital to keeping the system free of pollutants.

Aside from periodic maintenance, it is also essential to perform regular water tests to look for variations and verify if the water is within the desired parameters.

What to do When Your Shark Outgrows Their Fish Tank

Once again, I must affirm the importance of only acquiring the fish after you are sure that you can provide everything that the animal needs. This is even more important when talking about large fish. 

But I know that unexpected problems can happen, such as emergencies, abrupt financial difficulties, and even buying one species as if it were another. In cases when trouble happens or when the fish grows larger than the aquarium size, there are some actions we can take to remedy the problem.

The first option is to get a bigger tank. This is the most responsible way to deal with this problem as we will continue caring for our pet, offering it the ideal conditions.

For this, we need to acquire a bigger aquarium, preferably with a size that will be adequate for our shark for the rest of its life. Also, we also need to get new heaters, filters, and lighting correctly sized for the new tank. Remembering that we must cycle the aquarium before populating it.

The other solution is to donate the fish. The donation can be made in different ways. Freshwater sharks are a very desired and beloved fish within the aquarium hobby, so we should have no problem finding a new owner for our beloved aquatic friend.

The best option is always to donate to someone close, like a friend. In this way, we can visit our old fish and continue observing it through different stages of its life.

If this is not possible, there are several zoos and aquariums (public and private) that accept fish donations. Most of these places will be happy to receive a large shark to put on an exhibition or to be part of their breeding programs. The ideal for this case is to contact them and ask if they accept donations.

Another place to find people who are willing to accept sharks for donation is via online aquarist communities in different forums, Facebook groups, social media, and other places on the internet.

Tank Mates for Tropical Sharks

Freshwater sharks are very cool species to keep in aquariums, especially in community tanks. Keeping different fish species together requires some basic knowledge on our part.

The main thing is to know the shark. Among the countless species, some are peaceful and friendly, proper to coexist without problems, even with smaller fish. Others are large and aggressive, will eat smaller fish, and demonstrate territorial behaviours, such as attacking other fish.

The same goes for the tank mates we want to keep. They must live in the same parameters necessary for sharks to thrive. Knowing the behaviour of future tank mates is also vital to ensure that it can be a potential threat to the shark.

Our Top 10 Freshwater Sharks for Your Aquarium

1 Borneo Redfin Shark

The Borneo Redfin Shark is a beautiful fish with a bright body and red dorsal and tail fins. It’s considered a shark for its fast-moving swimming behaviour and the big straight dorsal.

As schooling fish, they need to be kept in a group of at least six. Since they are very active fish with gregarious habits, they need large aquariums with a minimum of 65 gallons (300 litres). They are picky about water quality, so they should be kept by aquarists experienced with sensitive fish.

These sharks are not fussy about tank decoration but need a wide open space for swimming. They occur in acidic water and an environment with practically no light. Providing floating plants, driftwood, and tangled roots in the tank is a good way to create low-light environments.

An incredible fish to be kept in a dark water aquarium. In low light conditions, the colour of these animals will be intense.

It presents peaceful and friendly behaviour and can be kept in community aquariums without a problem. As they are fast and active fish, avoid using shy or slow species as tank mates. If this shark is in small aquariums, it can become aggressive, chasing the other inhabitants.

Omnivorous in habit, this species does not show any problem feeding on all types of fish food. The constant supply of live foods such as bloodworms and daphnia makes them exhibit a strong, deep colouration.

At a Glance

2 Bala Shark

Bala Sharks are beautiful fish with shining silver bodies, with fins contoured in black. Bala Shark is called a shark because of its high dorsal fin, which forms a triangle, resembling a marine shark fin.

As a peaceful fish, it hardly eats smaller adult fish. It has gregarious habits with a rigid hierarchy. It must be kept in a school of at least 6 specimens.

If kept in small numbers, the dominant members of the shoal will show aggressive behaviour towards the other members. We should never keep it in pairs or trios, especially adult fish.

They are large fish, reaching around 12 inches (30 cm) in aquariums, so they should be kept with tankmates of similar size as long as they are peaceful.

An 86-inch (325 litre) tank is the minimum size for keeping a small shoal. As an active species that inhabits fast waters, it should be kept in long aquariums with plenty of open space for swimming.

Is advisable to keep the aquarium water with a considerable to strong flow, so we imitate the characteristics of its natural environment, providing water with a high level of oxygen. 

As a species known to jump out of the aquarium, keeping the tank with a tight lid is a good idea.

In nature, this fish feeds mainly on plants and crustaceans. When in an aquarium, it will accept any food without problems. A shy species that is easily startled and can injure itself by hitting the glass or decorations.

Scientists suggest that the species is extinct in the wild, mainly due to the degradation of its habitat.

At a Glance

3 Black Sharkminnow

A recommended species for beginner aquarists, Black Sharkminnow is well known in the aquarium hobby, being one of the popular shark species. In their places of origin, these fish are called “Black Carp” and are cultivated on a large scale. These sharks are very appreciated in the local cuisine.

They display a dark colouration with a large dorsal fin. Juveniles are black, and as they develop, they acquire a greyish tone with beautiful iridescent spots. 

They reach large sizes, up to 35 inches (90 cm) in the wild. In aquariums, they hardly exceed 19 in (50 cm). These are large fish that need aquariums of at least 171 gallons (648 litres).

The tank for this species must be as long as possible. As they are very territorial fish when adults, having refuges and caves in the aquarium helps to mitigate this behaviour.

They are peaceful fish when juveniles, but they become aggressive and territorial as they grow. Aggression increases if they are kept under stress or in small spaces.

Black Sharkminnow can be kept with other fish as long as they are of similar size and behaviour. But they are intolerant to other sharks; we must keep only one of its kind in the aquarium.

They are omnivorous fish, though they have a great tendency towards herbivory. In captivity, they will readily accept commercial, live, and fresh foods without any problems. We must prioritize the supply of vegetables and fish food with vegetable protein.

At a Glance

4 Columbian Shark

The Columbian Shark is a South American catfish. It’s a large and very active species, which requires large spaces for swimming. They must be kept in aquariums with a minimum of 75 gallons (284L). 

They are indifferent to aquarium decoration, but it is best to provide sandy substrate and driftwood forming caves and hiding places. The species appreciates well-oxygenated water with moderate to intense water flow.

In the wild, Columbian Sharks live in various water conditions during the course of their lives. As juveniles, they reside in freshwater rivers. But as they become adults, they move to brackish waters closer to the coast. 

Owners must mimic these conditions in the tank. Adult animals must be kept in high salinity, such as brackish or marine water. When kept in freshwater, their lifespan is considerably shortened, in addition to not developing adequately. This characteristic makes this fish not the ideal species for novice aquarists.

It’s a very peaceful shark species and can be kept in a community aquarium with different types of fish. They can even live with smaller fish as long as they don’t fit in their mouths. Peaceful with other sharks and catfish, being most active when kept in small groups.

Having carnivorous habits in an aquarium, the transition to accepting dry foods can be tricky and requires patience. Fresh and live foods like crabs and shrimp will be accepted quickly.

In aquariums, these fish can go through some periods in which they exhibit strange behaviour, like irregular and persistent swimming. Many attribute this behaviour to migratory instincts, and the increase in aquarium salinity can control these impulses.

We must be cautious when handling Columbian Sharks. Like other catfish, this shark has spines that get caught in the mesh of the net, which can hurt the fish. The first spine at the base of its dorsal fin has poisonous compounds; care must be taken to not be stung, as it can cause unpleasant and painful swelling.

Another peculiar behaviour is that these fish make sounds. The sounds are produced by rubbing the pectoral fins together. When keeping a group, it’s normal to hear them. Scientists believe that noises are used for communication among the group and possibly for echo localization.

At a Glance

5 Harlequin Shark

The Harlequin Shark is not large-sized, being able to inhabit aquariums above 36 gallons (135 litres). These fish are sensitive to water quality. They should not be kept by inexperienced aquarists.

The perfect tank for this animal should be long and have a strong flow of water, simulating its place of origin. The presence of large rocks and driftwood forming burrows and shaded areas is necessary for the well-being of the fish. There may be plants present, but they can be eaten by the shark.

These fish are omnivores and avid eaters of biofilm and algae. In aquariums, feeding is not a problem, as they easily accept dry, live, and fresh foods like pieces of vegetables, nauplii, and dry fish food. They are fish with interesting feeding habits, even seen feeding on the biofilm formed on the skin of hippopotamuses.

The best thing to do is keep this animal in a species-only tank due to its territoriality and the specific conditions it needs to thrive. But, if you want to keep a community tank, choose your tank mates carefully.

Juveniles are shy and spend much time hiding among the crevices in the aquarium. These sharks are solitary fish that, as they grow and develop, become territorial and will attack other fish, especially those of similar appearance.

At a Glance

6 Rainbow Shark

Rainbow Shark is a fish often seen in aquarium stores, where unsuspecting aquarists (especially beginners) acquire it on impulse. 

This shark has a greenish-brown body with a black spot at the base of the dorsal fin. The dorsal, anal, and pelvic fins are red, which gives a unique beauty to the species. The albino form is quite common in the aquarium trade.

An easy-to-maintain species, it is a good entry shark for beginners. It can be confused with the Redtail Shark. The main difference is that Rainbow Shark has all fins red with a lighter black colour.

They require medium-sized tanks, at least 52 gallons (200 litres). Although they do not reach a large size, they need a long aquarium, as they are a very active species and an excellent swimmer.

This fish is always moving in the bottom, so the ideal is to provide it with a sandy substrate. Rainbow sharks prefer densely planted environments, forming refuges among the vegetation.

Water with plenty of dissolved oxygen and a strong flow is a must. A tip when keeping these fish is to provide strong lighting, which facilitates the development of algae, a primary food in their diet.

A nice species to be used in community tanks because it hardly shows aggressive behaviour. It usually just expels invaders from its territory, not attacking them. The aquarium must have caves, refuge, and ample space for swimming.

These sharks are territorial and aggressive towards conspecifics.

They are omnivorous fish with a great tendency to herbivore. In captivity, they will readily accept both dry and live food. Plant-based foods should be provided regularly such as specific fish food and fresh vegetables.

Although often sold as algae eaters, they are not efficient in eliminating them.

At a Glance

7 Red Tail Shark or Red Tail Black Shark

The beautiful Red Tail Shark is unfortunately listed by the IUCN (red list of endangered animals) and may already be extinct in the wild.

They are sometimes confused with the Rainbow Shark, but in this species, the red colour in this fish is only present in the caudal fin. There is also the albino variation, common in the aquarium trade.

Despite not reaching large sizes, given their active behaviour, they require an aquarium with a minimum of 53 gallons (200 litres). In nature, these fish are found next to the substrate, between roots and vegetation in places with plenty of oxygen available. In fish tanks, we must imitate these conditions.

Red Tail Sharks are pacific with other species but are territorial and aggressive towards conspecifics. It must be kept only by aquarists who have experience with territorial fish.

When choosing tank mates, take their territoriality into account. This species can become territorial when it reaches maturity and eventually become aggressive with similarly shaped fish, especially in a small aquarium without many refugees.

With omnivorous habits, it presents much of its diet as being herbivorous. In captivity, it will readily accept both dry and live food.

At a Glance

8 Roseline Shark

Roseline Shark is a relatively new species in the aquarium hobby, having appeared around 1990 and growing in supply in recent years. They are beautiful torpedo-shaped fish with an intense red line over a silver body with iridescent scales.

These fish have gregarious habits, so it is advisable to keep them in schools of over 6 individuals. They need large tanks of at least 55 gallons (210 litres) as they are very active. They are very peaceful sharks and a great addition to large community aquariums.

In their natural environment, they are omnivorous, feeding on a multitude of foods such as worms, insects, and plant material. In captivity, it will readily accept all types of food. Plant food should be provided regularly. 

It’s interesting to point out that the colour of the red line can be intensified with a rich and varied diet.

Unfortunately, it’s another shark species listed as ‘Endangered’ on the IUCN Red List of Threatened Species. According to data, the population of these animals has decreased by around 50% in the last 15 years. Collection for the aquarium trade has been largely responsible, although habitats are also being degraded by pollution.

At a Glance

9 Siamese Flying Fox Shark

Flying Fox Shark is a peaceful fish with other species and aggressive with similar-looking animals. In aquariums, they hardly exceed 5 in (12 cm), but in the wild, they can reach more than 6 inches (16 cm).

Despite being omnivorous, this species prefers to feed on plant material. It’s one of the species often called algae eater, but it is not effective at this task. In aquarium accepts all types of food, dry, fresh, and live.

It’s not a picky fish about aquarium decor, but it will be more comfortable with the presence of rocks and roots. Plants can be used and will not be attacked, even those with soft leaves. This fish needs excellent quality water. It cannot withstand high levels of nitrogen and other pollutants. It is best to provide well-oxygenated water and a moderate flow.

Flying Fox Sharks can be kept in aquariums of at least 26 gallons (100 litres). As a peaceful fish, it can coexist with smaller fish without problems. When adults, they are aggressive against similar-looking fish.

An easy species to keep and very good for those aquarists who want to migrate to more sensitive species in terms of water quality.

Even though it’s been present in the aquarium hobby for many years, scientists still do not know all the places where this fish naturally occurs. Many populations have declined or completely disappeared in recent decades. All individuals found for sale are bred on fish farms.

At a Glance

10 Silver Shark

Silver sharks are not good fish for home aquariums. Due to their large size, active behaviour, and being a species of large shoals, they must inhabit large tanks with at least 800 gallons (3028 litres).

These are fish to be kept only by experienced hobbyists.

Silver sharks need ample space to swim freely and have impeccable water quality, with a high level of oxygen. They will quickly die in waters with the presence of pollutants. As great jumpers, the aquarium should always be properly closed.

Specialized to feed on small insects on the surface of the water, in aquariums they can have problems accepting dry food.

Of peaceful behaviour, they can live with countless species of fish. Tank mates mustn’t be slow or shy, or they may not be able to eat and will be stressed by the active behaviour of these sharks.

At a Glance

11 Siamese Algae Eater

I personally would not consider this one to be a shark but a lot of people do! Siamese algae eaters have some resemblance to sharks so they get grouped with aquarium sharks. 

They are very peaceful schooling fish that can be kept with smaller fish without any problems. Some people find them hard to keep as they can be aggressive but this only happens when they are kept solitary or in reduced spaces. I have 3 ranging in size from 1 inch to 3 inches and they are not aggressive at all. I have them in a tank with Endlers and Dwarf Flame Gouramis and they are the perfect tank mate. 

They are supposed to be known for their amazing algae eating but I’ve found as they get older they either get lazy and wait for the fish food or they just lose their taste for the algae. (I find the Otocinclus to be a better algae eater).

In an aquarium, they will have no problem feeding on commercial fish food. It is important to avoid the constant supply of high-protein foods such as live foods as consumption of such can result in obese and malnourished fish.

It is a great species to be kept in community aquariums above 26 gallons (100 litres). They are also resistant and adapt well to virtually any water parameter.

At a Glance

Freshwater Shark FAQs

What size tank do freshwater sharks need?

The size of the tank will depend on the species. The smallest species can be kept in a 26-gallon (100-litre) aquarium.

What kind of shark can you keep in an aquarium?

Freshwater ornamental sharks comprise several species, including catfish, barbs, algae eaters, and other fish.

Would a shark outgrow a fish tank?

When we plan and study the species we want to keep, this shouldn’t happen. But impulse buying can lead to this problem.  These fish are active and large in size so it is very important to provide them with an appropriately sized tank.

How long do freshwater aquarium sharks live?

The species that have the longest lifespan live more than 10 years, easily reaching 15 years.

What do freshwater aquarium sharks eat?

The vast majority of shark species are omnivorous and feed on a range of foods, such as dry commercial fish food, fresh foods such as bloodworms, and live foods such as nauplii.

Are freshwater sharks aggressive?

Yes, many of the species are aggressive, especially with similar-looking fish.

Can sharks and goldfish be together?

It is not recommended, mainly because sharks are tropical fish that live in warm waters, while Goldfish prefer warmer waters.

Can a shark live in a fishbowl?

No, sharks need ample space to swim freely.

What is the smallest freshwater aquarium shark?

The smallest species would be the Roseline Shark and the Siamese Algae Eater, reaching around 5 inches (14 cm).

Do aquarium sharks eat algae?

Some species like Siamese Algae Eater and Flying Fox Shark are known to feed on algae.

Do aquarium sharks eat plants?

Yes, some species will enjoy eating plants with more tender leaves.

Can you put shark fish with guppies?

Species with small mouth sizes and peaceful behaviour like Roseline Shark and Siamese Algae Eater can be kept with Guppies without problems.

Can you have only one Bala shark?

It is not advisable. Like any other schooling fish, we should always keep more than 3 specimens together.

Aquascaping a Freshwater Shark Aquarium

Aquascaping freshwater shark aquariums can be a tricky task.

When we talk about aquascaping, we mean beautiful displays with driftwood, beautiful rocks, and lots of plants forming a dense area of ​​vegetation. In the case of sharks, these fish are large and need wide open spaces to swim. Some species can also eat plants, while others like to dig into the substrate, destroying the plants.

Having the presence of a planted region in the tank is ideal for some shy shark species, which use these places as shelter and also as food. As I always say, it is essential to study the behaviour of the species before deciding on the type of tank; only then do we provide the decoration that best suits these fish. If you want to have a beautiful tank planted with sharks, here are some tips.

Always have a large aquarium, this way we can provide a lot of hiding places through the aquascape, with decorations and plants, while having a beautiful open area for swimming. This type of setup is stunningly beautiful, especially when we keep schooling sharks.

A biotope-type tank is always a good choice. Biotopes are styles that mimic the characteristics of the region where the fish occurs. These montages require a lot of studies to determine the correct species that live along our main fish species (sharks, in this case).

Regardless of our choice, sharks have specific needs, which should always be valued. First, choose the species you want to keep, then design the aquascape that best suits it. This is the best way to join sharks and aquascaping.

What do you Think? Are Freshwater Sharks Right For You?

Freshwater sharks are beautiful and popular fish in the aquarium hobby, but they are not a fish for all aquarists. Some species are sensitive concerning water quality, and almost all of them are large, active fish that need a lot of space in the tank. 

It is essential to obtain these fish only when we are absolutely sure that we will provide everything the fish needs for its entire life, which can be quite long.

These fish are so named because they have physical similarities to their saltwater relatives, such as an erect dorsal fin. Another characteristic that draws attention to these animals is their behaviour, always swimming, exploring, and interacting with their aquarium, which makes them very fun to watch and care for.

As for the tank, each species needs a specific decoration, but they all require large aquariums. It is vital to remember to change the water and clean the tank during maintenance.

It is not always possible to be able to own and care for these sharks at home. We must always take into account the correct sizing of the tank in accordance with the needs of the species, space, and available time to take care of our animals. When we can’t provide for their needs, we must turn the page and look for other fish that need smaller tanks and are easier to maintain.

And you, what do you say? Are freshwater sharks the right fish for your aquarium? (call to action)