Iridescent Shark Care Requirements – Tank Parameters, Fish Pairing, etc

Iridescent Shark Care Requirements – Tank Parameters, Fish Pairing, etc

Thanks for stopping by! This complete, comprehensive guide on Iridescent Shark care will teach you about their tank parameters, health, diet, behavior, tank pairings, and more!

Species Summary

Pangasianodon hypophthalmus, commonly known as an iridescent shark is a shark catfish that belongs to the family Pangasiidae which is commonly found in the waters of the Southeast Asian region. Contrary to the name, it is not a shark. It is heavily cultivated as a food source in rivers of Chao Phraya and Mekong basin. Iridescent shark is also known as siamese shark and sutchi catfish. Its meat is commonly called Swai meat


The iridescent shark is most commonly found in the rivers Mekong, Chao Phraya, Mae Klong in the regions of Thailand, Cambodia, Laos, and Vietnam. The fish is found in rivers that possess rocks in the bottom and swims in middle layers of water.

These fish are also available on pet stores and can be found in online stores also. Commercial fish farms also do farming of this breed so it is easily available with a moderate price range.

Iridescent Shark Lifespan

Most iridescent sharks have a lifespan of more than twenty years on an average. If you provide them with the right environment, these fish can survive for a very long time. On the contrary, if conditions are not favorable, it can significantly affect their lifespan and shorten it.


  • Size – Most commonly, iridescent adults attain a length of 4.3 feet and, a weight of 44 kg.
  • Color – The iridescence in their color depicts a shiny surface which is indicative of their name. The adults are greyish, with the fins, more towards a blackish shade. The young ones have two black strips with one present on the lateral line and one below the lateral line.

Iridescent Shark Aquarium Care

One of the challenges people face is that they buy the fish at a juvenile stage, unaware of the fact that it can grow as big as four feet, so a right sized aquarium is of great importance for keeping this specie. Here I will guide you about the optimum conditions you should follow to provide a natural-like habitat to your Siamese fish.

Irridescent Shark Tank

irridescent shark tank

The tank you should choose to keep this specie should be similar to a river model having space for swimming and loaded with driftwood and rocks at the surface of the tank. The iridescent shark will spend most of its time in the open middle column of water and there must be open room for them to swim freely.


The tank size must be 300 gallons for a fully grown iridescent shark, to provide enough space in which they can feel comfortable and swim easily. For juveniles, a 100-gallon tank is enough but as they grow, they become giant-sized and require more space.


For iridescent sharks, it is best to use substrate that mimics the natural habitat conditions. Using sand or gravel is a good option. Whichever substrate you are going to use, keep in mind, the cleanliness of the tank is very important. Otherwise, the water in the tank will become cloudy.

The substrate layer must be 2 inches thick.

Plants and Decorations

irridescent shark plants and decor

Plants are of not of much importance when we talk about iridescent sharks. They prefer to move in shallow parts of rivers in the natural habitats, so you should focus more on providing good material for just the tank’s bottom. Placing lesser plants would be a better idea, as it will help improve the quality of water in the tank. Placing larger sized plants which can reach up to the surface, or plants placed in the tanks for decoration, both will be of no use as the former will take up more space and reduce the freely moving environmental conditions for the fish. An iridescent shark is not the right option for those, who want to keep their tank green with lots of plants.


The most important thing to make the environment favorable is to keep the temperature of the tank water in an optimum range. The temperature should be 72ᴼF to 79ᴼF, with a pH ranging between 6.5 to 7.5, and hardness of water within a limit of 2 to 20dGH.

It’s always better to think ahead and monitor the water conditions regularly, as once they get disturbed, it becomes difficult to bring the conditions to optimum values especially in a larger sized tank and also when you are a beginner in dealing with large capacity tanks.


Moderate lighting to normal tank lighting is required in the iridescent sharks’ tank. At the juvenile, low lighting is needed for the iridescent shark. If the lighting is increased, these fish are easily stressed out.


The recommended cleaning of the tank is twice a month. Take a brush, soap, and cotton cloth to properly clean the tank. If proper cleanliness of the tank is not maintained, these catfish can acquire different infections of the skin.

Iridescent Shark Health

irridescent shark health

Iridescent sharks are not susceptible to any specific illness, but you still need to be careful to watch out for common affliction, which can occur possibly. Skin infections are common in these catfish as they do not have scales on their bodies.

As these fish have greyish skin color, any skin problem is easily noticeable. The most common problem occurring in the skin-related issues is ich. It can be easily seen as white patches on the surface of the fish body and the fish tries to rub its body against some hard object in the tank.

You must lookout for the quality of water in the tank to avoid any skin problems and it is better to avoid such ailments to occur in the first place than to finding the solution afterward as we heard it right “Prevention is better than cure.”

Iridescent Shark Food & Diet

While talking about the right food and diet of iridescent sharks, it’s all about providing different varieties. These fish are not choosy in terms of food despite being omnivores.

So it brings responsibility to you, to find the food items which can fulfill the requirements of vitamins and nutrients to keep them in a healthy state. You should come up with a proper diet plan by doing your research because the health and lifespan of the fish can be shortened if the food is deficient in micronutrients.

Good quality flakes are recommended in the diet of iridescent sharks. Brine shrimp and live or frozen bloodworms are also a good option in feeding. They will serve as a good source of protein.

As this fish is an omnivore, so they love to eat meat, but you can also include fruits and vegetables in the diet.

Behavior & Temperament

These sharks love to move and they show quite a jumpy behavior. This fish loves the company of other companions with it and they love being in groups and do better. These fish show calm behavior when accompanied by other similar fish, and they can easily be stressed out if they are kept alone.

Shy and nervous behavior is observed when people keep these fish alone which is not recommended. When we talk about the temperament of these fish, they are peacekeepers. They do not usually show any signs of aggression with other fish and are mostly calm.

Iridescent Shark Fish Pairing

irridescent shark fish pairing

To choose a pairing companion for this fish, you must keep in mind the size of that other breed. You should not add a fish smaller in size than iridescent fish because it will eventually be eaten by them as they grow much larger and are omnivores. Danios, tetras, and barbs are small-sized fish and are not recommended to be added as companions. The best option is to add an iridescent fish of similar size or you can add these breeds as companions:

  • Kissing gourami
  • Bichir
  • Fire eel
  • Oscar
  • Texas cichlid

The iridescent sharks do not like those companions which cause a disturbance in the tank, so avoid adding such fish breeds, otherwise Iridescent sharks would end up causing damage to the well-being and health of these fish also. You must consider the size of your tank before adding any companion breed.

Tank Mates for the Irridescent Shark

Iridescent Shark FAQ

  1. How big do iridescent sharks get?

    Adult iridescent sharks reach a length of about four feet and attain a bodyweight of 44 kgs.

  2. Does iridescent shark bite?

    These fish are easily stressed out if disturbed, so they can hit the aquarium glass and can injure their head. They can also bite if smaller sized fish is added in the tank with them. It will become the food of these catfish.

  3. Can iridescent sharks live with cichlids?

    Yes, Iridescent sharks can live with cichlids which are moderately aggressive such as Texas cichlids and Salvin’s cichlids.

  4. Why is my iridescent shark swimming upside down?

    If your iridescent shark fish swims upside down, it is an indicator of a problem with the buoyancy of the fish which indicates that the swim bladder of the fish has some disorder. Due to the swim bladder disorder, the shark will float upside down at the aquarium top, seeming to be dead but not dead. The swim bladder could be infected due to bacterial infection of too much air swallowing.


After reading this article, you have come to know that iridescent sharks are large-sized fish, and proper care of the requirements of their tank must be kept in mind while bringing them into housekeeping.

When adults, they need a lot of space in the tank, which only a few people can manage as it is expensive. Though Juveniles are smaller in size and they can be kept in smaller tanks, but as they grow in size, you also have to change the size of the tank progressively.

These fish can easily cope and get along with larger sized fish companions, but the small ones could become their prey.

Feeding this fish is not a problem as they are not choosy when it comes to feeding, you just have to make sure to provide varieties of food for them.

Iridescent shark is a great aquarium fish, if you take proper care of all the points I have mentioned in this article earlier.

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