The Colombian Shark Catfish is a very attractive fish and fun to observe, but it gets fairly big!

The Colombian Shark Catfish is a very appealing fish because of its “shark” like appearance. At first glance, this spectacular animal truly does look like a shark. Yet its underslung mouth rimmed with barbels quickly gives away its true identity. This is a catfish that it gets pretty big, just under 14 inches (35 cm), and is a graceful and powerful swimmer. A school of these impressive catfish makes a wonderful showpiece for the large aquarium!

The Colombian Shark Catfish is a peaceful fish and very good in a community aquarium as long as it is kept with the right tankmates. Although a predatory fish, they are naturally nervous animals. When kept singly they are very nervous, unhappy, and won’t settle down. They need to be kept in a school of at least three fish to thrive. Other tank mates need to be of similar size, tolerant, and peaceful.

The Shark Catfish adult is a brackish water fish, preferring hard water with salt added. As juveniles, a salinity of 1.002 sg is recommended as a minimum, but a full-grown adult will require a specific gravity of at least 1.010. Actually, this catfish along with the Eel Catfish Plotosus lineatus, are representatives of two important families, Ariidae and Plotosidae respectively, that are unique among catfish because they are primarily marine fish. Almost all other catfish, with just a few exceptions, are intolerant of salt and will not survive anything more than a slight salinity.

The appealing appearance of these popular Shark Cats and their small size at the pet store, at around 2 to 4 inches, make them desirable for even the beginning aquarist. Yet because of their adult size and schooling requirements, as well as their increasingly brackish water requirements as they mature, these fish are recommended for an intermediate fish keeper. An aquarist must make sure they have an aquarium that’s big enough and be willing to maintain the salinity before trying to house these unique fish.


Scientific Classification


Silver-tipped Shark – Quick Aquarium Care

Aquarist Experience Level:Intermediate
Aquarium Hardiness:Moderately Difficult
Minimum Tank Size:75 gal (284 L)
Size of fish – inches13.8 inches (35.05 cm)
Temperature:71.0 to 79.0° F (21.7 to 26.1&deg C)

Habitat: Distribution / Background

The Silver-tipped Shark Ariopsis seemanni (previously Hexanematichthys seemanni) was described by Gunther in 1864. They are widespread along the Eastern Pacific, found in Pacific-draining rivers and estuaries from the southern Gulf of California to northern Peru. Other common names they are known by are Colombian Shark Catfish,Tete Sea Catfish, Shark Catfish, and White Tip Shark Catfish. Along with other members of the Ariidae family of catfish, they are also called Sea Catfish.

They are listed on the UCN Red List of Endangered species as Least Concern (LC) because this species has a wide distribution with no major threats or indications of a declining population. It is common in many parts of its range and occurs in a wide range of habitats.

The Colombian Shark Catfish are found in medium and large rivers, but mainly inhabit the mouths of rivers emptying into the Pacific Ocean. They are usually found in brackish waters, but are a migratory species that will travel many miles inland to fresh water. These fish live in freshwater environments when they are young, and move to brackish conditions as they mature. They can live in fully marine conditions as adults.

In the wild this a schooling species. Although they are omnivores, their diet consists largely of crustaceans such as shrimps, crabs, and other invertebrates. They also consume small fish, amphipods, benthic organisms, and insects, as well as some plant matter. Juveniles ranging in size from 1 1/2 inches to 8 1/2 inches have also been observed scale-feeding, and fish scales have been found ingested by larger specimens as well.

  • Scientific Name: Ariopsis seemanni
  • Social Grouping: Groups – These fish live in schools in the wild.
  • IUCN Red List: LC – Least Concern


The Shark Catfish resembles an actual shark in appearance and swimming movements. It has an underslung mouth with maxillary barbels and a pair of chin barbels. The dorsal fin is located close and is pointed, and there is a venom-producing gland on the first dorsal spine. It has a rather long anal fin with 26-46 rays. These fish can grow to 13.8″ (35 cm) in length when kept in proper brackish conditions, and have a life span up to 15 years.

As juveniles they are a silvery-grey color with white undersides and black pectoral, pelvic and anal fins. The common names incorporate some of the characteristics such as the white tips on its pectoral and anal fins as well as the black linings on its dorsal and tail fins. The adult coloration is a little duller but it is still a very striking fish.

One of the most interesting behaviors is the sounds they make, which can be quite loud. They produce audible clicking or grinding sounds by rubbing their pectoral fins against the sockets. Although the reason they make sounds is unknown, it may be used as signals between fish to keep the school together in murky waters or as an echolocation system similar to dolphins. In murky habitats, this type of audio navigation works better than sight or lateral lines. These fish become more vocal if feeling threatened, which can be confusing when other fish kept in the same aquarium are make clicking sounds.

  • Size of fish – inches: 13.8 inches (35.05 cm)
  • Lifespan: 15 years

Fish Keeping Difficulty

The Silver-Tipped shark is moderately difficult to care for and so is not recommended for beginners. Although small juveniles, usually under 4 inches in length, are sold as freshwater fish, as this fish matures it will need more brackish conditions (higher salinity), up to full saltwater.

They are suggested for an intermediate fish keeper because of the required brackish conditions, their adult size, and the need for companions. A 75 gallon aquarium is large enough for one specimen, but without the company of their own kind, the Colombian Shark Catfish will act nervous and somewhat neurotic. A school of 3 or more of these fish is needed which will require at least a 100 gallon aquarium. These are a peaceful fish but are predatory. As they grow smaller tankmates will become food.

  • Aquarium Hardiness: Moderately Difficult – Due to their nervous nature, this fish tends to fall ill frequently even in well maintained tanks.
  • Aquarist Experience Level: Intermediate – With their large size and brackish water requirements, they are recommended for the Intermediate fish keeper.

Foods and Feeding

In the wild Shark Catfish feed on small fish, insects, crustaceans, and carrion. They are considered to be are omnivorous but prefer meaty foods. They use their barbels to detect food sources and similar to sharks, they are sensitive to electric fields which enables them to find food hidden under the gravel.

As juveniles they will generally eat all kinds of live, fresh, and flake foods. To keep a good balance give them a high quality flake food or pellet everyday. As they grow they will eat pellets, earthworms, mussels, prawn, strips of octopus or fish, and sinking tablets.

  • Diet Type: Omnivore – Although omnivorous this fish prefers a greater protein component to its diet.
  • Flake Food: Yes – It make take some time to train them to eat flake.
  • Tablet / Pellet: Yes
  • Live foods (fishes, shrimps, worms): Some of Diet – Live shrimp are a delicacy!
  • Vegetable Food: Some of Diet
  • Meaty Food: Some of Diet – Crustaceans like shrimp, and strips of squid or other fish are recommended.
  • Feeding Frequency: Several feedings per day – This fish grows quickly, requiring a large quantity of high quality foods as well as variety.

Aquarium Care

The tank should have weekly water changes of 30% and the substrate should be vacuumed. Make sure to remove any dead and diseased fish as the Silver-Tip will feed on carcasses potentially getting sick itself.

Be cautious when performing tank maintenance or handling the fish for any reason. They don’t bother you when cleaning the tank, but be careful to not bump them. This fish has a venom-producing gland on the first dorsal spine that can cause a cause a nasty, painful swelling. The sting is comparable to a bee sting which can be immersed into hot water. This will denature the venom and relieve the pain. Sometimes medical attention is required if the individual is particularly sensitive to the toxin.

  • Water Changes: Weekly – Do water changes of 30% weekly to keep these fish healthy.

Aquarium Setup

Silver-tipped Sharks are large, active fish that need ample swimming space. They grow fast, reaching a length just shy of 14 inches in about 2 years. A minimum sized tank of 75 gallons can work for a single fish, but these are naturally nervous animals that need to be kept in a school of at least 3 individuals to thrive. A 100 gallon tank or more will be needed for a group. Signs that they are not comfortable include cowering in a corner or behind a filter.

As this is a riverine species, good oxygenation and water flow is appreciated. Highly oxygenated water can be accomplished using an undergravel filter and a strong power head. Strong currents are appreciated, sometimes they will continually swim into the current produced by the filter. They can jump, so a fitted cover with subdued lighting works best.

These are very active fish so need a lot of unobstructed swimming area. As juveniles they are pretty shy though, and will appreciate some cover. A good decor would be some driftwood or mangrove roots, which help mimic their surroundings in the wild. Most aquatic plants do not do well in brackish conditions but those that do will not be uprooted. The substrate like with most catfish should be soft and smooth to assure they do not injure their barbels.

Freshwater is “okay” for juveniles under 2-3 inches, but they are fast growers reaching their full size in about 2 years. These small fish will soon need a slightly brackish environment of no less than 1.002 sg to thrive. The amount of salt then needs to be increased as they grow. For an adult a specific gravity of 1.010 is recommended as a minimum, but a higher salinity of 1.015 sg to 1.025 is better. If all seems well with the environment but the fish demonstrate frantic swimming behavior, increasing the salinity can help.

  • Minimum Tank Size: 75 gal (284 L) – Silver-tipped Sharks are large and active and should be given ample swimming space. 75 gallons is adequate for a single fish but 100 or more gallons is recommended for a small group.
  • Suitable for Nano Tank: No
  • Substrate Type: Any – Be careful with sharp edges on the gravel as it can injure the barbels as they root around the substrate.
  • Lighting Needs: Any – They do not require caves and shelters although some cover is appreciated especially in high light environments.
  • Temperature: 71.0 to 79.0° F (21.7 to 26.1&deg C)
  • Range ph: 6.8-8.5
  • Hardness Range: 10 – 30 dGH
  • Brackish: Yes – Although it can survive in a freshwater tank as a juvenile it is recommended to have at least 1.002 sg. Salt must be added as the fish ages with 1.010 sg recommended for an adult.
  • Water Movement: Strong – As a migratory species they enjoy a current, sometimes they will spend hours swimming in-place in front of the outlet of a strong water filter.
  • Water Region: All – These are a demersal fish (bottom feeders) but will spend time swimming in open areas.

Social Behaviors

The Silver-tipped Shark are generally a good community fish with fish their own size that are not territorial. In the wild they are a schooling fish so a group of at least three or more is recommended. If kept alone, they will be noticeably uncomfortable and exhibit skittish behavior such as darting about the aquarium and quickly swimming from top to bottom frequently. When settled in with other shark catfish, they will still be rather lively and often on the move, which is one of the attractions of keeping them. They are one of a few catfish that is active during daylight hours.

Don’t keep them with fish that are much smaller since the shark catfish are predaceous and may eat smaller fish. A good choice for tankmates includes other larger schooling brackish water fish such as Monos, Scats, Garpikes, and even the more docile cichlids like green chromides. Aggressive fish do not make good companions, nor do killifish or livebearers, which they will simply see as food.

  • Venomous: Yes – They have a venom-producing gland on the first dorsal spine. If impaled, the toxin that will produce a painful sting and swelling, and submersing the affected area in hot water will relieve the pain. Medical attention is required in rare cases.
  • Temperament: Peaceful – Silver-tipped Sharks are highly predatory to smaller fish.
  • Compatible with:
    • Same species – conspecifics: Yes – These fish require a school of at least three fish.
    • Peaceful fish (): Safe – Best kept with other large schooling fish like scats, monos, garpikes, and non-aggressive cichlids.
    • Semi-Aggressive (): Monitor – Do not do well with aggressive fish like territorial cichlids.
    • Aggressive (): Threat
    • Large Semi-Aggressive (): Threat
    • Large Aggressive, Predatory (): Threat
    • Threat – These are fast and aggressive at feeding time!
    • Shrimps, Crabs, Snails: Threat – is aggressive
    • Plants: Safe – Although they will root around in the substrate, they usually do not uproot plants or disturb rockwork.

Sexual differences

Difficult to sex when young, under 8 inches (20 cm), but mature females are thicker-bodied than males and have lighter fins.

Breeding / Reproduction

The Shark Catfish have not been successfully bred in aquariums. In the wild they are mouth-brooders with the male brooding the eggs. The issue with breeding these fish in aquariums is the difficulty replicating their natural breeding behavour. These fish will spawn in marine environments, the male carries the eggs in his mouth until incubation is complete. Once this happens, the male swims upstream to deposit the fry into freshwater where they begin their lifecycle and migrate back to the brackish water to live and the the oceans to spawn.

  • Ease of Breeding: Difficult – The issue with breeding these fish in aquariums is the difficulty replicating their natural breeding behavior. This fish is a migratory mouthbrooder that produces very few large eggs which the male will watch over.

Fish Diseases

Silver-tipped sharks are fairly hardy fish when mature but are subject to the same diseases as other tropical fish. The best way to proactively prevent disease is to give them the proper environment and give them a well balanced diet. The closer to their natural habitat the less stress the fish will have, making them healthier and happy. A stressed fish is more likely to acquire disease.

One of the most common freshwater fish ailments is ich. Some other common diseases these fish can contract are Dactylogyrus Gill Fluke Disease, Skin Fluke, Cestoda infestation, and Metacercaria infection. High nitrate levels can also cause Silver-tipped sharks to develop infected barbels; this makes it difficult for them to navigate and eat normally. Maintain nitrate levels below 20 ppm.

Because they are a scaleless fish, catfish can be treated with pimafix or melafix but should not be treated with potassium permanganate or copper based medications. Malachite green or formalin can be used at one half to one fourth the recommended dosage. All medications should be used with caution.

Anything you add to your tank can bring disease to your tank. Not only other fish but plants, substrate, and decorations can harbor bacteria. Take great care and make sure to properly clean or quarantine anything that you add to an established tank so not to upset the balance. For information about fish diseases and illnesses, see Aquarium Fish Diseases and Treatments.


The Silver-tipped Shark or Shark Catfish is readily available and moderately priced at around $5.00 (2013)

Featured Image Credit: Vladimir Wrangel, Shutterstock