In the market for something extra-large for your super tank or huge pond?
The Iridescent Shark (Pangasianodon hypophthalmus) might just be the ticket for those who are suitably experienced and looking to advance their skills in the hobby.
Not actually a shark per se; these are large freshwater catfish who also go by the name Siamese Shark and Sutchi Catfish. They certainly look like a catfish as opposed to a real shark, but perhaps their ‘naked’ skin and iridescent color lends itself to the shark description.
The Iridescent Shark is actually a very peaceful and gentle fish that is among one of the largest species of hobby fish you can acquire for freshwater tanks. They are even known to be timid and easily spooked despite their size and stature.
These are social schooling fish as juveniles that hail from two wide, deep rivers in Southeast Asia, which are the Mekong and Chao Phraya. This gives them plenty of space for some serious migration behaviors in the wild plus, as adults, they then tend to be solitary creatures and like their space.
We’ll take a deep dive into why these energetic giants of the freshwater kingdom have gained such a following in recent decades and why you might want to consider them if you have adequate space requirements such as a super-sized tank or large pond!
Iridescent Shark Behavior
Considered a peaceful, gentle giant of the hobby, they can be timid when first introduced to your new tank after sourcing. After several weeks, you should be able to observe your Iridescent Sharks becoming more active and engaged out in the wide open.
Since these fish are usually bought as juveniles, you should expect to keep a group of them which keeps them less stressed and reduces their nervous tendencies. If you end up getting a more mature and therefore larger individual, it still needs large peaceful fish as company to bring out the best in their behaviors.
Not recommended to be kept as a solo fish, these sharks prefer to school and prefer the company of their own kind to stay calm. There have been reports of these fish jumping out of the tank or hitting the glass when spooked and cracking the glass when doing so.
Avoid having this tank in a setting with high traffic or where loud noise might be possible to prevent these calamities. Approaching the tank slowly is also advisable to avoid startling them.
These are strong and active swimmers who are powerful and energetic. They need plenty of space for open swimming and to scavenge around in the tank. Given that in the wild, these sharks migrate some distance, they can be expected to enjoy an active lifestyle. They are also highly active during the daytime, which is a little more unusual for the catfish family, so they are enjoyable to observe as long as you don’t startle them unnecessarily!
Iridescent Shark Lifespan
If you cater to the needs of your Iridescent Sharks, you could expect them to live for, on average, around 20 years, which is a considerable amount of time to invest in a hobby. You must be sure you have ample space and the capacity to care for them that length of time.
We will discuss more on their exceptional tank requirements a little later in this article.
Iridescent Shark Appearance
As one of the largest freshwater fish you can acquire and house in a hobby tank, you should be prepared that at full maturity, they usually reach up to 48 inches in length. This is not an inconsiderable size for a hobbyist’s undertaking!
Their trademark is their prominent dorsal fin, reminiscent of an actual shark, which they are definitely not!
They possess a rounded, oblong-shaped body that is built for speed.
Iridescent silver in color with a white underbelly, they have fins that mimic the typical shark shape, which have some white striping present on the tips along with thick black trim.
They are a shiny, glossy-looking specimen under aquarium lighting, and although not a vibrant color, they will still impress.
Small barbels around their mouth help them find food as they do not have great vision.
Large bulging eyes that are expressive are another key characteristic for these fish. They are superb hunters and are always on the lookout for food like most catfish tend to do.
Iridescent Shark Habitat And Tank Requirements
As always, we want to achieve optimum health for fish we keep in captivity by closely mimicking their natural habitat. Their wild origins are the swiftly flowing river waters of Southeast Asia.
Let’s look at some specifics that are needed to provide these epic fish with a great quality of life that best suits them for optimum health.
Iridescent Shark Tank Conditions
Powerful filtration to create a fast-flowing water current is good for these fish as they love a current, and this is the best way to recreate it in your supersized tank. You should speak to an expert stockist in pond management of super tanks for the best advice for your setup as you will need a more technical arrangement.
Providing filtration beyond your tank capacity is ideal to ensure that they are getting better than clean water conditions. And these fish will make a real mess, given their size.
They enjoy a soft substrate, and darker colors will show off their light silvery coloring even better.
Decorate with smooth and rounded rocky formations and driftwood to avoid scratching the delicate skin that has no scales and can make them susceptible to injury and infection.
As Iridescent Sharks are highly active, you’ll want to ensure that you have plenty of open swimming areas. Avoid vegetation that is too intrusive into the midsection of the water column or needs too much maintenance. This is where these sharks like to spend most of their time, in the middle stratum of the water column.
Good ideas for live plants include Amazon Swords, Anacharis, Java Moss, Water Wisteria, Water Lettuce, Amazon Frogbit, and Hornwort. Fast-growing plants will work best since they are likely to gobble up much of your plant life. Everything is fair game!
They will enjoy hiding in the shorter plant life and revel in the open areas for their active swimming behavior. Keep plants low and around the perimeter to allow your Iridescent Sharks to have the most activity possible. Floating plants also work well to keep the lighting subdued.
Water changes need to be weekly and at least 25% changed over for optimum water quality.
Water conditions should be noted and maintained as follows:
- pH of 6.5 – 7.5
- Water hardness between 2 – 20 dGH
- Temperature between 72 – 79ºF (22 – 27ºC)
- Lighting conditions are ideal moderate and nothing too jarring
Iridescent Shark Tank Size
The minimum tank size for an adult Iridescent Shark is 300 gallons, and if you add more, then add another 150 gallons for each individual. There isn’t really any point in having a small tank that a group of juveniles will rapidly outgrow, so get the biggest tank you can at the outset and also factor in other community fish.
Realistically, a 1000 gallon tank will house enough fish to keep them from getting stressed or a massive outdoor pond with a heater for locations that get slightly cooler outside of the warmer months. Ideally, you will want a group of up to four or five in a single tank.
In terms of shape, you’ll want something long and rectangular that will allow them plenty of active swimming areas. Make sure it is deep too.
Avoid anything rounded that will impede their schooling nature.
Choosing Tank Mates For Iridescent Sharks
Having an Iridescent Shark school is an exceptional achievement if you can afford the space, tank size, and maintenance needed to keep them happy.
When it comes to finding friendly species for your peaceful Iridescent Sharks, you have plenty of options.
You will want to keep sizes of tank mates relative, nothing too small, or your Iridescent Shark WILL eat them. They are excellent hunters and will take advantage of anything that fits into their mouths.
The fish must be peaceful as anything aggressive will send your Sharks reeling with stress and make them ill as they can feel harassed.
Some excellent tank mate pairings that would work well include:
- Black Sharks
- Bichir
- Silver Dollar Fish
- Large Places
- Oscar Fish
- Fire Eels
- Salvin’s Cichlid
- Texas Cichlid
- Pearsei
Avoid invertebrates like shrimp and snails and other crustaceans like crabs as tank cleaners unless you are providing them as a live (quarantined) food supply, as your Iridescent Sharks will inevitably consider them a meal, and you’ll notice them disappear.
Avoid anything aggressive or small fish as the smaller species will become dinner too.
How To Feed Iridescent Sharks
Iridescent Sharks are omnivores and will enjoy a balanced diet of plants and proteins in their diet.
As larger fish, they are capable of eating larger sources of food. However, they tend to consume more plant matter as they age. Juveniles will prefer meaty proteins and live over frozen and pelleted.
Exceptional quality flaked or pellet foods are good for Iridescent Sharks as a base in their nutrition, but they will require supplemental live/frozen foods and homemade veggies to really help them shine.
Bloodworms, Brine Shrimp, Crickets, Earthworms, and blanched vegetables will all enhance their health and keep them in optimal condition.
If you choose to try using live feeder fish or shrimp, ensure they are appropriately quarantined before adding them to the main tank as prey for your happy hunters.
Smaller meals 2 – 3 times per day will help avoid overfeeding these fish. Iridescent Sharks should only be fed what they can consume in about a five-minute period to prevent bloating and gastric issues.
Iridescent Shark Common Health Issues
Most freshwater fish are susceptible to Ich (White Spot Disease), which, as the name implies, is easily distinguished by white spots on the body due to a parasitic infection.
You will often see your fish rubbing themselves onto decor in order to rid themselves of some of the discomforts from the parasite. There are, however, commercial treatments available to help treat Ich. If you see any Ich developing, you should treat the whole tank as it’s contagious, and it would be impossible to have a quarantine tank for the size and space these guys need.
Other conditions like Fin Rot and other parasitic infections are typical things to keep an eye out for, but the Iridescent Shark is considered quite hardy and has no major issues as a species. Their lack of scales, however, makes them susceptible to injuries that can lead to health issues if the water quality is poor.
Normally when these health hazards happen, it’s because the water parameters and quality have dropped. This means upping your game and cleaning schedule without fail to restore the tank to its best.
They can be minimized with a strict water cleaning and change schedule along with regular checking of your water parameters with a suitable testing kit.
How To Breed Iridescent Sharks
It isn’t possible to breed Iridescent Sharks in a home aquarium.
The ones you find from stockists are bred commercially, and on top of this, they usually administer or require hormone injections to make this possible for the hobby.
These sharks migrate in their wild reproduction and travel some distance to do so.
So are Iridescent Sharks Worth The Space And Upkeep?
We think Iridescent Sharks make a great option for the hobbyist who can accommodate a suitable amount of space and finances to keep these peaceful giants.
By either having a huge tank or a suitable pond system, they are surely a showstopper, but the fact remains that very few people in the hobby can accomplish this.
Just remember that their long lifespan can also be daunting to consider as well.
Oh, and resist the temptation to go full Austin Powers and add Bond-esque lasers to the mix to make them tougher and more intimidating.
These so-called sharks aren’t intent on doing anyone harm!
