Top 5 Freshwater Sharks for Aquariums (and How Big They Really Get)

You may have gone to the pet store and seen some freshwater fish labeled as “sharks.” These species are not true sharks but rather are members of the Cyprinidae family of carp and minnows. They just happen to look like sharks because of their slender, torpedo-shaped bodies and pointy fins. Beginners often buy freshwater sharks because of their attractive shape and hardiness, but they can grow much bigger than expected and have large tank requirements in adulthood. So, before you take home that adorable 2-inch (5 cm) shark at the pet store, let’s learn about their requirements and see if they are the right fish for you.

1. Red Tail Shark

Epalzeorhynchos bicolor

The red-tailed red sharkminnow is also known as the redtail sharkminnow. This species can be easily identified by its completely black body, fins and bright red tail. A red tail shark is small in size, but can reach up to 5-6inches (13-15 cm) as an adult. They need an aquarium that’s at most 4ft (1.2m). These sharks are native to Thailand’s rivers, streams and floodplains. They can live in temperatures between 72-79 degrees F (22-26 degrees C) and pH ranges of 6-8. They are omnivores and will eat anything, including fish flakes and sinking wafers.

Red tailed sharks live alone and are not known for their ability to interact with other fish. As they get older, however, they tend to be more territorial toward sharks of the same species as them. They are comfortable with semi-aggressive, similar-sized fish, such as African and South American cichlids. You can also pair them up with small, fast-schooling fish like giant danios, barbs, and other smaller fish. Avoid tank mates with peaceful fish, slow swimmers, nano creatures, or those that could be eaten.

2. Rainbow Shark

Epalzeorhynchos frenatus

This beautiful centerpiece fish also grows to 5-6 inches (13-15 cm) and looks very similar to the red tail shark. They are not nearly all black but have a darker gray coloration and red tail. Pet shops often sell different colors, including the Glofish and albino versions. They also come from Thailand and nearby Southeast Asian countries and can live in a broad gamut of pH levels between 6.5-8.0 and temperature from 72-80degF (22-27degC). They enjoy eating all kinds of community fish foods like pellets, wafers, blanched veggies, and frozen foods. Additionally, they will occasionally eat algae if they’re hungry.

Although rainbow sharks are socialized more as juveniles than adults, they eventually become aggressive towards their own species. Keep one rainbow shark per 4 feet (1.2 m). Aquarium length. Suitable roommates include similar-sized cichlids, loaches, gouramis, and rainbowfish. If it does not work out, or the rainbow shark continues to bully them, be ready to get rid of certain tank mates.

3. Roseline Shark

Sahyadria denisonii

The roseline shark’s common name comes from its shorter red line, which lies on top a longer horizontal black stripe running through the middle of its body. Denison barbs are also called this species. They can reach 4-5 inches (10-13cm), and have beautiful yellow-black markings on their tails. They are native to fast-moving rivers in India and have dense vegetation close to the banks. They would thrive in a planted aquarium. They are a schooling fish that requires 3-5 people to keep them happy. A tank should be at least 4 feet in length (1.2 m) and larger. They are a peaceful and smaller fish that would be great with rainbowfish and larger livebearers. You shouldn’t have any problems feeding them various frozen, freeze-dried and gel foods.

4. Siamese Algae Eating

Crossocheilus sp.

You need an algae eater that can cover larger tanks. The Siamese Algae eater (SAE) is a 6-inch (15 cm) Siamese. It has a silvery, brownish body with a bold, black line down its side. It can eat blackbeard algae as well as other types of alga and fish food leftovers. They tend to eat more algae as juveniles because the adults are large enough to get the lion’s share of the fish food you feed. Fasting for around a week may be necessary to get the adults hungry enough to pursue algae.

SAEs come from rivers and floodplains in Southeast Asia and can easily live in pH of 6-8 and tropical temperatures of 72-79degF (22-26degC). Although you could get them in a group if you have a lot of algae-eating power, they can become territorial towards other sharks as well. You could keep one of them in a 50-gallon aquarium or larger. They will be content living alone.

5. Bala Shark

Balantiocheilos melanopterus

Our biggest shark is 12 inches (30cm) in length. It is also known as the tricolor shark or silver shark. It has a silvery body with light-colored fins and thick, black edges. They can live in temperatures between 72-82degF and 72-82degC as they are native to Southeast Asian rivers or lakes. They are very easy to feed, and will happily eat floating or sinking food as well as invertebrates, such as shrimps and snails.

We do not recommend this species for most aquarists because of the enormous tank size requirement. You need to allow them plenty of space. A bala shark is a large fish that needs to be kept in a group of at least four fish. It can be difficult to get an aquarium with at minimum 6 feet (1.8m), so hobbyists often end up getting just one for a 125-to 150-gallon tank. They can be kept with smaller, semi-aggressive fish of similar size, such as catfish, loaches and gouramis.

If you are serious about caring for a freshwater fish shark, and want to ensure it has the right size tank and tank mates. Then check out our list of recommended retailers to purchase fish online. All the best with your aquariums. Enjoy nature every day.