Colombian shark – Ariopsis seemanni: everything you need to know
The Colombian shark is a very interesting fish that many aquarists do not know about. And the ones that do tend to have inaccurate information.
In fact, we consider this species to be one of the most underrated aquatic pets out there!
To explain why, we decided to put together this handy guide. It will teach you the basics of Colombian shark care and show what makes this fish so special.
Despite their name and appearance, Colombian sharks (scientific name: Ariopsis seemanni) are not a type of shark at all.
This species actually belongs to the catfish family. However, its appearance and swimming pattern closely resembles that of a shark, leading to its unique nickname.
Colombian sharks have a wide distribution. They can be found as far south as Guatemala and as far north as the Gulf of California. The fish reside in rivers and tributaries that flow into the Pacific Ocean, resulting in some unique care requirements.
This is a relatively popular species in the fishing trade. They are often sold as juveniles in pet stores around the world. However, Colombian sharks grow rapidly and require a lot of space to really thrive.
The typical life expectancy of a Colombian shark in captivity is usually 10 to 15 years. While rare in a controlled environment, they can actually live a bit longer. These fish reportedly have a much longer lifespan in the wild.
Colombian sharks are greatly affected by their environment and the quality of care. While these fish have a long shelf life, nothing is guaranteed.
This species has some unique needs, and not meeting those needs could significantly shorten the lifespan of the fish.
It’s not hard to see why Colombian sharks are known as sharks. They have that same iconic profile complete with a tall, triangle-shaped dorsal fin. Sizeable anal and pectoral fins further complete the look.
Once you get a little closer, the catfish’s characteristic features become more apparent. For example, these fish have lower mouths, which is one of the catfish’s most recognizable traits. Around the mouth, Columbian sharks also have several pairs of barbels.
The predominant color of these fish is silvery gray. Juveniles tend to be more vibrant in terms of coloration. While the adults lose some of that vibrancy, they’re still eye-catching.
The bright silver color is accompanied by a white belly. The fins are black and semitransparent. Most fish also have a subtle white stripe at the tips of their pelvic, anal, and pectoral fins.
As we mentioned before, the dorsal fin is tall and triangular. Although the dorsal fin appears innocent due to its transparent nature, it can be dangerous.
Colombian sharks have a pointed dorsal spine that is connected to a venom-producing gland.
The backbone is fully capable of biting owners, so be careful when cleaning the tank. The sting is comparable to a bee sting, and can result in painful swelling!
The average size of an adult Colombian shark is around 10 to 14 inches long.
However, they can get much bigger than that. In larger tanks with the right conditions Columbian Sharks have been known to reach lengths of 20 inches!
Colombian Shark Care
The care of Colombian sharks is interesting in that it evolves as they age. Because they are sold so often in pet stores, many assume they are easy to care for.
In reality, they can become more demanding as they age.
There is a lot of misinformation floating around (see what we did there?) about these fish. This often leads to stunted growth or premature death.
If you want your Columbian Shark to reach its full potential, follow the recommended care guidelines below.
Let’s start with the size of the tank. Due to their enormous potential size, having a large tank is a must for Colombian sharks.
At a minimum, you will need a tank that can hold approximately 75 gallons. That’s enough for a single Colombian shark.
If you plan to keep a small group, you will need a 100 gallon tank at a minimum.
Author’s Note: Aim for the biggest tank you can get. These fish are good swimmers. They need plenty of room to explore, stay healthy, and thrive.
This is where things get tough for the Colombian shark. Although advertised as a true freshwater fish, this species prefers some salinity.
You see, Colombian sharks move through various water conditions throughout their lives.
When they are juveniles, they reside in purely freshwater rivers. However, they come closer to shore as adults (where the waters are brackish).
When fully grown they can even spend time in pure marine conditions if need be! Dedicated owners will need to make those changes to their tank as the fish ages.
Generally, it is recommended that you provide brackish water for the Colombian shark. They do best in hard water with lower salinity. Here are some water parameters to follow.
- Water temperature: 75°F to 80°F
- pH levels: 7.0 to 8.0 (approximately 7.5 is ideal)
- Water hardness: 10 to 12 KH
- Specific Gravity: 1.002 minimum for juveniles, 1.010 when fully grown
Due to your unique water requirements, you must do consistent water testing throughout the week. This will allow you to have up-to-date information on the status of your tank and the fish that live inside it.
What to include in your tank
Setting up your tank for Colombian sharks is not too difficult. Because these fish are strong swimmers, it is best to keep the environment relatively sterile in terms of decoration.
Use sand as a substrate. If you have younger fish, you can incorporate some modest decorations to give them some places to hide. Driftwood driftwood or mangrove roots work well.
You can incorporate some plants here and there. They must be plants that can survive in brackish conditions. Anubias, Java Fern, and Sago Pondweed should work fine. Keep plants sparse and focus on creating open space for fish.
Author’s Note: Strong filtration is essential. Due to their large size, these fish can quickly sour water quality. Invest in a powerful filter that can cycle volume efficiently and regularly. We recommend the fluval fx4.
Another important aspect to consider is the flow of water. Colombian sharks live in fast-moving rivers. Therefore, they prefer a considerable flow. Use your filter outlets and pumps to create good oxygenation and ample flow.
In general, Colombian sharks are quite hardy. They can handle fluctuations in water conditions without much trouble.
But that doesn’t mean they aren’t immune to all the standard tropical fish ailments.
These fish can suffer from Ich, skin flukes, bacterial infections, fungal infections, branchial fluke disease, and more. Fortunately, most of these problems can be easily avoided if you maintain the water conditions.
Many inexperienced owners find problems with their Colombian sharks due to lack of salt. Without that subtle salinity, these fish can become stressed and sick. Be sure to monitor conditions regularly to prevent this.
An important note about Colombian sharks: they do not have scales. As a result, diseases cannot be treated with traditional copper-based medicines. You will have to use temperature-based remedies or drugs with malachite or formalin.
Food and Diet
Colombian sharks are not particularly picky when it comes to diet. They are omnivorous in nature, feeding on things like crustaceans and shrimp.
In captivity, you can provide them with a wide variety of foods. They readily accept sinking flakes or granules.
You can also provide live, freeze-dried, or frozen foods. These fish enjoy meat-based foods like shrimp, live fish, earthworms, and more.
Columbian sharks must be fed twice a day. Only feed them enough food that they can eat in about five minutes to avoid the possibility of overeating.
behavior and temperament
Colombian sharks are mostly peaceful. They spend their days occupying the lower and middle parts of the aquarium.
Author’s Note: However, they may venture to the surface if they are kept in a single-species tank and feel comfortable enough to explore.
Like other catfish, Colombian sharks are large scavengers. You can find them looking for food at all hours!
The only time you may encounter aggression problems is when these fish are kept with smaller species. Colombian sharks have a high prey drive.
This means that they will often mistake smaller fish for food. Even if they shared the tank with a smaller species when they were young, those smaller fish will eventually become food.
Colombian Shark Tank Mates
Interestingly, Colombian sharks are good community fish. The only caveat is finding similar sized fish that have the same needs.
The best tank mates will be other Colombian sharks. These fish are not territorial at all. In fact, they are actually considered to be schooling fish in the wild!
A group of at least three fish is recommended. A small group helps Columbian sharks feel more secure in their surroundings.
In addition to fish of the same species, you can also group Colombian sharks with other non-aggressive brackish fish. Here are some good tankmates to consider:
- Gobies (we like the bumblebee)
- target fish
- green chromides
It’s important to keep a close eye on any tankmates you try for the first few weeks. Any serious sign of aggression will require you to separate the fish.
The breeding of Colombian sharks is very difficult to do in captivity. Few see success due to unique spawning process (adults spawn in open ocean).
After the female lays her eggs, the male will fertilize them. It will then carry them in its mouth until they hatch. He continues to catch the baby fish fry until he can swim upstream and deposit the fry in a freshwater environment.
Recreating those sudden changes in the environment is nearly impossible in captivity.
Rather than give general guidelines on how to test it (as on other sites), we encourage you to avoid this until there is a proven track record of these fish being bred in captivity. The breeding process wears out over time, even if it is unsuccessful.
We hope you now have a better understanding of Colombian shark care and what makes this species so interesting.
With such a unique appearance and the interesting conditions in which they live, there are very few fish like them!
If you’ve had these fish in the past (or have some now) and are interested in including some of their stories or pictures, please let us know!