Iridescent shark Care Guide: Diet, Tank Mates, Diseases, Breeding & More

Updated: December 17, 2022

The iridescent shark is a freshwater fish that is commonly kept in aquariums. They are a hardy fish that can tolerate a wide range of water conditions, making them a good choice for beginner fishkeepers.

Despite their name, iridescent sharks are not actually sharks. They are a type of catfish that is native to Southeast Asia.

Iridescent sharks are a popular choice for aquariums because of their striking appearance. They are silver-grey in color with iridescent blue stripes running down their body.

These fish can grow to be quite large, so it is important to provide them with plenty of space to swim. They are also known to be rather active swimmers.

Species overview

The iridescent shark (scientific name: Pangasianodon hypophthalmus) is a type of freshwater catfish that’s native to Southeast Asia.

They are most commonly found in the Mekong Basin, which covers parts of Laos, Cambodia, Thailand, and Vietnam.

This fish prefers slow-moving waters with a lot of vegetation. They are bottom-feeders and primarily eat plants and small invertebrates.

Iridescent sharks are a popular choice for aquariums because of their unique appearance. They are silver with black stripes running down their body. This coloration is what gives them their name, as the stripes appear to be iridescent when they catch the light.

These fish can grow to be quite large, so it’s important to make sure you have a tank that’s big enough to accommodate them. They can also be a bit aggressive, so it’s important to keep that in mind when choosing tank mates.


Iridescent shark

The first thing you’ll notice about this freshwater fish is their unique coloration. These fish are a beautiful silver color with a very noticeable iridescent sheen.

This effect is caused by the way their scales reflect light. The scales on their body are very small and close together. This creates a smooth surface that reflects light in an eerie but amazing way.

Adding to the effect is the fact that their fins are almost completely translucent. When you see an iridescent shark swimming around, it’s almost like they’re a ghost!

These fish have a long and slender body shape that tapers off at the end. Their dorsal and anal fins are both large and begin about two-thirds of the way back on their body.

The caudal fin is forked and relatively large. The pectoral fins are also large and have a bit of a webbing effect going on between them.

The eyes on these fish are very small and beady. This gives them a bit of an “evil” look that some aquarists find off-putting.


Iridescent sharks have an average lifespan of about 10 to 12 years. However, there are reports of some living for up to 20 years in captivity.

As with any animal, the quality of care they receive will play a big role in how long they live. Things like water quality, diet, and stress can all lead to a shortened lifespan.


The average size of an iridescent shark is between 4 and 5 feet long. However, they can grow to be up to 6 feet long. These fish are also known to be very active and require a lot of space to swim.


Tank Size

The recommended tank size for an iridescent shark is 125 gallons. This fish can grow to be over 2 feet long so you need to make sure you have enough space for it to swim and grow.

If you want to keep more than one iridescent shark in the same tank you need to add at least another 55 gallons for each fish. This fish is also not recommended for beginner aquarists as they require a little bit more care and attention.

Water Parameters

The iridescent shark is a tropical freshwater fish that requires warm water to thrive. They are found in rivers and streams in Southeast Asia where the water temperature is between 77 and 86 degrees Fahrenheit.

A tank that is too cold will cause the iridescent shark to become sluggish and eventually die.

The ideal water parameters for an iridescent shark are:

  • Water temperature: 77 to 86 degrees Fahrenheit
  • pH levels: 6.5 to 7.5
  • Water hardness: 8 to 12 dGH
  • Alkalinity Levels: 4-8 dKH

What To Put In Their Tank

When it comes to setting up the inside of an aquarium for Iridescent Sharks you can be as creative as you want. There aren’t any specific things that this species NEEDS to have, which gives you plenty of options.

We recommend some of the standard decorations that you find in a lot of freshwater tanks. There are a ton of great plants you can include (like hornwort or water wisteria). You can even throw in some floating aquarium plants too!

Rocks, driftwood, and caves are all suitable as well. It’s important to avoid going overboard with this since these fish like some room to swim.

Also, if you’re keeping your Iridescent Sharks in a smaller tank then it’s going to be difficult to include a lot of this stuff anyway.

A classic gravel substrate is always a good choice, but you can do with something soft and sandy if needed too (use other species you keep as a guide with this).

Common Diseases

There are a few diseases that you should be aware of if you’re keeping iridescent sharks. While these fish are pretty hardy, they are still susceptible to the same illnesses as other freshwater fish.

The most common disease you’ll see in these fish is ich. Ich is a pretty well-known disease in the fish-keeping world, and it’s no surprise that it affects iridescent sharks too.

This disease is characterized by white spots on the body, fins, and gills of your fish. If left untreated, it can be deadly.

The good news is that ich is pretty easy to treat. There are plenty of products on the market that will rid your fish of this disease.

The other disease you might see in your iridescent shark is hole-in-the-head disease. This is a pretty ugly disease that’s caused by poor water quality.

It presents itself as, you guessed it, holes in the head of your fish. While it’s not deadly, it can cause a lot of damage to your fish if it’s left untreated.

As always, the best way to prevent these diseases is to maintain a clean and healthy environment for your fish. A well-maintained tank will go a long way in keeping your fish healthy and happy.

Behavior & Temperament

The iridescent shark is a schooling fish, which means it does best when it’s around other fish of the same species. In the wild, these fish travel in large groups. So, it’s important to keep that in mind when you’re stocking your aquarium.

Ideally, you should have at least six iridescent sharks. But, the more the better. These fish are very active and need a lot of space to swim. So, a larger tank is always better.

When it comes to temperament, the iridescent shark is a bit of a mixed bag. It can be calm and peaceful one minute and then aggressive the next. These fish have been known to attack other fish, especially if they’re smaller in size. They’re also known to nip at the fins of their tank mates.

So, it’s important to be careful when choosing tank mates for iridescent sharks. They do best with other fish that are similar in size and temperament.

Tank Mates

The iridescent shark is a large, predatory fish. Because of this, it’s important to be careful when choosing tank mates.

This species is known to be finicky when it comes to food. In the wild, they feast on smaller fish, crustaceans, and mollusks. In the home aquarium, they can be trained to eat pellets and flakes. But, live food is still their favorite.

For this reason, it’s best to avoid keeping iridescent sharks with smaller fish. They might see them as a snack!

Instead, opt for larger, more robust species. Tank mates that are a similar size and have a good bit of muscle are best. Here are some examples:


These fish are livebearers, which means that they give birth to live young rather than laying eggs. This makes the breeding process a bit different (and easier) than other fish.

For starters, you need to have a male and female. These fish can be difficult to sex, but a good rule of thumb is that males are usually smaller than females.

Once you have your male and female, put them in a breeding tank. The tank should be at least 50 gallons. It should also have plenty of hiding places and live plants.

The water temperature should be between 78 and 82 degrees Fahrenheit. The pH should be between 7.0 and 8.0.

Once the fish are in the breeding tank, the female will start to produce young. She can have anywhere from 10 to 50 babies at a time!

The young will be born live and fully-formed. They’ll be able to swim and feed on their own.

You can remove the adults once the babies are born. The babies will do fine on their own. Just make sure to feed them plenty of live food.


The iridescent shark is a popular fish for many aquarists because of its unique look and personality. They are a hardy fish that can be a great addition to any community tank.

While they are relatively easy to care for, there are a few things to keep in mind to make sure they stay healthy and happy.

Overall, we think the iridescent shark is a great fish for any aquarist and would recommend them to anyone looking for a new addition to their tank!