Columbian Shark: Species Profile

Category: Catfish

Common Names: Columbian Shark

Scientific Name: Arius jordani

Family: Ariidae

Minimum Tank Size: 75 Gallons

Care Level: Easy

Temperament: Peaceful

Max Size: 10 Inches

Temperature: 74-80 F

pH: 7.0-7.5

Tank Level: Bottom

Colors: Silver, Tan

Diet: Omnivore

Breeding: Difficult

Xocolatl [CC BY-SA 3.0]

Columbian Shark

Columbian Shark Species Overview

The Columbian shark is a catfish native to South America. It’s most commonly found on the Columbia coastline. The sharks are omnivores and are often sold in pet stores as small juveniles, growing larger than their small size initially suggested.

They are also known as Jordani sharks, west American cat sharks, and blackfin sharks. On average, a Columbian shark will grow up to 14 inches in length. They have a unique underslung mouth and maxillary barbels. When young, they are silver in color with white undersides and black pectoral fins. The undersides of their pelvic and anal fins are black as well.

A Columbian shark will typically require a lot of care, making them best suited for intermediate or advanced fish keepers. The species prefer to live in numbers and do their best with two other companions in their tank.

Distinguishing Features

The Columbian shark is a distinct-looking species of catfish that resembles a shark when it swims (giving it its somewhat confusing name). Its dorsal fin is pointed and located quite close to the head. The “sharks” have a special gland in their dorsal fins that produces venom.

This species is known for its long anal fin, which has between 26 and 46 rays. Another fascinating attribute these shark-like fish possess is their ability to emit sound by rubbing their pectoral fins against their sockets. This practice allows them to ward off other fish and potential predators.

Elsewhere in their bodies, these interesting fish have a noteworthy ear bone. It’s sensitive to low-frequency sound, helping them better navigate their environments without depending entirely on their eyesight. Loud noises around the home have been known to make these catfish, particularly juveniles, nervous.

The fish also have anticoagulant-containing saliva. That means the saliva keeps a prey fish’s blood flowing once the catfish starts eating it.


The Columbian shark is native to Pacific-draining rivers in Central and South America. Despite its name, it is a species of sea catfish commonly found in rivers and estuaries. They populate waters as far south as Guatemala and towards the Gulf of California.

They’re born in freshwater environments but migrate into salt water. This practice is one of the main reasons they are unsuitable for novice fish keepers. Their aquariums must be transitioned from fresh to saltwater as the fish ages.

In their natural environment, they hunt as scavengers, often targeting the bottom of rivers for food. They’re omnivores and often have a blended diet of meat and plants. Their preferred water is brackish and with a heavy flow.

The healthiest Columbian sharks are kept in large tanks that reproduce these qualities of their original environment as closely as possible.


Columbian sharks start relatively small and are often sold as juveniles in pet stores. As they age, they usually reach between ten and 14 inches in two years. However, it is not unknown to find Columbian sharks achieving a length of up to 20 inches.


If your Columbian shark is well taken care of, it can live up to 15 years or even longer. To give them a solid foundation for a long life, you will first need to ensure your fish has a healthy tank with a proper pH balance. Maintaining a nutritious diet and having a tank at least 75 gallons tank are additional crucial steps to keeping your shark happy and healthy.


When these sharks are young, it can be difficult to tell the difference between males and females. But, as they grow, the females appear rounder or plumper than their male counterparts. In addition, a female’s fins are lighter in color compared to the male. Males, on the other hand, are more streamlined in appearance.


Despite their shark-like movements, these fish are not particularly territorial. They are schooling fish, meaning they do best with other members of their species.

When they’re young, Columbian sharks are shy, something that may be exacerbated if you only have one shark in a tank or there is nowhere for your fish to hide.

Tank Parameters

Columbian sharks require large tanks to thrive. They grow much larger than their juvenile size would suggest and will need enough space to swim around actively. It’s also necessary to install a tank with a top, as the species has a habit of jumping up and sometimes out of the water.

Minimum Tank Size

A Columbian shark will flourish in a relatively spacious environment. At a minimum, the tank should be 75 gallons for one fish and 100 gallons for three fish (the preferred number given they will school in the wild).

Your Columbian shark will need a great deal of room to move around since they are likely to reach a length of at least 14 inches in length. Given that, be prepared for those tiny juveniles to run out of space quickly!

Water Parameters

While juveniles can survive in freshwater (and do so in the wild), adult Columbian sharks need a saltwater environment. This requirement means that it’s crucial to have the correct salinity balance if you want your fish to live a long, healthy life. As they grow, you should increase the amount of salt in the water.

Consider adding an under gravel filter to ensure your tank matches the appropriate water parameters. You should change around one-third of the water once a week as the sharks are sensitive to dirty water.


The optimum temperature is in the range of 71-79 ℉. This temperature can be achieved and should be maintained through a heater.


Fish are generally capable of living in water with a pH between 6.5 and 8.0. But knowing what pH to aim for helps with caring for species like the Columbian shark.

Columbian sharks prefer a water pH of 7.5. But your fish will do well if you keep the pH between 7 and 8. If the pH is out of balance, either too high or too low, the fish may not grow as large as it would otherwise, remain inactive, sleep more than usual, and even become sick and die.


Your tank’s water should be salty, with 1.002 sg salt when the fish are juvenile, increasing to 1.010 as they age. The tank should have decent water flow as these fish are used to swimming in a current.

Tank Setup

When setting up the tank, you will need to consider several factors, such as what substrate you intend to use, like sand or gravel. You will also want to ask yourself the following questions:

  • What decorations or plants do you plan on using?
  • What type of lighting will you use?
  • Does the tank have an appropriate filtration system?
  • How will you heat the water?


Columbia sharks do well in a tank with any variety of substrates. But, avoid the sharpest gravel as this species has been known to injure themselves on it.


Most types of aquarium decor are well-suited to a Columbian shark’s tank. You should stick to the classics like rocks of various shapes and sizes, plants to help keep the aquarium clean and give the shark somewhere to explore, and pieces of wood.

Often, fish keepers choose wooden pieces that give the shark a place to hide if it feels nervous.


Columbian sharks aren’t picky about which plants they prefer in their environment, but you may find that your shark digs around at the base of the plant. You may also find it hard to keep plants alive in the high-saline environment that your shark requires.


As nocturnal fish, these sharks only require a little light and are usually comfortable in several lighting conditions. You could use an LED, halogen, or fluorescent light above the tank, but avoid any source that might be too strong.


If you want to maintain your shark’s health, a strong filtration system is a must. The species is sensitive to poor water quality and will suffer if the water dips below a healthy level.

By investing in a high-quality filter that regularly cycles the water, you’ll help lower the chance that your fish will get sick. You might also use your filter, in addition to pumps, to increase the water flow and oxygenation in the tank and, therefore, better reproduce the fish’s natural environment.


The water temperature needs to be around 71-79 ℉, so you will need to use a heater to maintain the temperature. You may want to choose an external or internal heater that is easy to find at any pet store or specialty store.


Columbian sharks are omnivores. They feed on plants as well as other fish and crustaceans. Their diet includes shrimp, crustaceans, pellets, live and freeze-dried foods, and live earthworms.

You should provide your sharks with a high protein diet consisting of live options and flake food. This balanced approach is particularly beneficial to supporting growing juveniles. Variety is also important in their diet, so look to change their diet regularly. One day you might feed your shark mussels, the next earthworms, the next brine shrimp, and so on. These fish enjoy eating small fish as well.

Regardless of what diet you give your Columbian shark, ensure your pet is fed twice a day. However, they must not overfeed as this could impact their overall health. With that in mind, make sure you don’t let them feed for more than five minutes.

As they grow, it’s important to transition to using high-quality flake food regularly. Older examples of Columbian sharks will likely avoid meat.


Breeding Columbian sharks in your home aquarium is not an easy task. Indeed, it can be challenging to set up the aquarium to accurately replicate its natural habitat and, therefore, encourage breeding. In the wild, Columbia sharks are mouthbrooders. This term is used to describe fish that carry their eggs in their mouths.

Specifically, when it comes to Columbian sharks, the male takes on this role. Once the eggs have been fully incubated, the male swims upstream and deposits the eggs (known as fries) in freshwater. It is here that the baby fish are born. They eventually migrate back to the brackish water, where they spend their adult lives. This context is why mimicking the proper water salinity is so important in your home tank.

Common Diseases

Unfortunately, there are a few common diseases that Columbian sharks suffer from. One of the most common is ICH or Ichthyophthirius multifiliis. It’s caused by a protozoan parasite that causes white spots on your fish’s skin and gills.

It is an issue that frequently affects freshwater fish and is alternatively known as white spot disease. If you notice these white spots, see your fish scratching itself, or notice your fish acting more lethargically than usual, it may have ICH.

Other diseases a Columbian shark may suffer from include gill fluke disease, Cestoda infestation, dactylogyrus, and a metacercaria infection. Gill and skin flukes are common parasites that impact aquarium fish. Many fish keepers notice them for the first time as a reddish tint around their fish’s gills. They feed off the fish’s blood and may make it hard for the fish to breathe.

A Cestoda or tapeworm infestation occurs when a group of flattened worms infest a fish’s body and produce larvae that further invade body tissues. A dactylogyrus infection occurs in a fish’s gills and is most common in the late fall and early winter.

Potential Tank Mates

While the Columbian shark can do well with other kinds of fish, the best tank mates for them are other Columbian sharks. They do best around other fish they won’t see as a food source.

Given that, it’s essential to avoid smaller species of fish as there is a higher likelihood they could display aggression or even try to eat them. You might want to consider lionfish, gobies, and targetfish. These candidates should do well around a Columbian shark. However, you will need to monitor your pet to see how they do around any new additions.