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10 Types of Catfish for a Freshwater Aquarium

Eric is an aquarium enthusiast with over two decades of experience caring for a wide array of tropical fish.

The plecostomus is one type of catfish for the freshwater aquarium.

The plecostomus is one type of catfish for the freshwater aquarium.

Catfish Species for the Home Aquarium

Freshwater catfish are some of the most interesting fish you can keep in your home aquarium, and also among the most industrious. There are many types, and they vary widely in size, needs, and temperament.

Generally, catfish are key members of the clean-up crew in your fish tank. Many are scavengers that will munch up any excess food that falls to the gravel. Others eat algae and can help you keep your tank free of the green stuff. Some do both.

Stocked correctly, catfish can be wonderful fish, and I can’t imagine having a fish tank without them. Unfortunately, they are also among the most misunderstood aquarium fish, and it is easy for beginners to make mistakes when choosing them.

Just as with other types of aquarium fish, a great deal of research and thought should go into stocking catfish. This article is intended to serve as a starting point by presenting a general overview of the different types of catfish for aquariums.

10 Types of Catfish

The rest of this article will cover many of the different catfish you'll see in the aquarium hobby. Some are widely available, while others are a bit rarer. A few of them I suggest you avoid, but odds are one or more of these fish are right for your aquarium.

  1. Corydoras
  2. Common Plecostomus
  3. Rubbernose Pleco
  4. Otocinclus
  5. Synodontis (Upside-Down) Catfish
  6. Iridescent Shark Catfish
  7. Pictus Catfish
  8. Chinese Algae Eater
  9. Striped Raphael (Talking) Catfish
  10. Glass Catfish

Read on for more information on each of these fish.

1. Corydoras Catfish

The little cory catfish is one of the most popular aquarium bottom dwellers, and a great small catfish for 10-gallon tanks and larger. They are shy, peaceful fish that only grow to a couple of inches in length, and they spend most of their time shuffling around the substrate looking for food. When they are still they often hide under plants or in decorations.

Cories are schooling fish that should be kept in groups of six or more to cut down on stress. They are fairly easy to care for and should be fed sinking pellets as a supplement to the food they will scavenge on their own.

Types of Cory Catfish

There are a wide variety of cories available for the home aquarium. Here are a few cories you’ll often see in the pet store:

  • Bronze Cory
  • Albino Cory
  • Pepper Cory
  • Pygmy Cory
  • Bumblebee Cory
  • Panda Cory
  • Sterba’s Cory
  • False Julii Cory
  • Skunk Cory

One more “cory” you may encounter is the emerald green cory or emerald brochis. These guys grow a bit larger than true cories but are still fairly small fish topping out around three or four inches.

When choosing, try not to mix and match varieties unless you have a tank large enough to support several different schools.

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2. Plecostomus

The common pleco is the "suckerfish" often seen stuck to the aquarium glass. It is sold in pet stores as three or four-inch juveniles but can reach an adult length of a couple of feet. Obviously, this fish is not a good choice for any but the largest home aquariums. Think 150 gallons or bigger.

The common pleco is a prolific algae eater, and if you do happen to have a large enough tank it can help you keep things clean. You will want to supplement its diet with algae wafers to be sure it gets enough to eat. It’s also a great idea to have a nice chunk of driftwood for your pleco to rasp on, and some dark caves for hiding.

Large plecos can be tough on live plants and sometimes become more aggressive as they age. Otherwise, if you have a big enough tank, there are some beautiful varieties of pleco to choose from. Just make sure you thoroughly research whichever variety you are interested in to make sure you can accommodate them as adults.

3. Rubbernose Pleco

If you love plecos and are thinking of ignoring everything I just said and cramming a common pleco into your small tank, put on the brakes and instead consider the rubbernose pleco. They include all of the pros and cons of their larger cousins but only grow to an adult length of five or six inches. You can keep these guys in tanks 30 gallons and up.

Another small pleco catfish you might consider is the bristlenose pleco. These guys grow to about the same size as the rubbernose and are appropriate for the same size tanks.

If you have a tank under 30 gallons and you really want a pleco you might be feeling a little discouraged right now. It may be tempting to put fish in situations that aren’t appropriate for them and hope for the best, but that approach rarely works out.

Take heart. If you have a ten or twenty-gallon tank you won’t be able to have a pleco. So, how about a bunch of tiny pleco-like fish instead?

4. Otocinclus

The tiny otocinclus catfish, or oto for short, isn’t a miniature plecostomus, but it kind of looks like one. These small catfish only grow to an inch or two in length and are sometimes referred to as “dwarf suckerfish”. They eat algae and stick to the sides of the glass, but unlike plecos they won’t harm your live plants.

Otos should be kept in schools of six or more, and are appropriate for any tank ten gallons or larger. Naturally, you will want to be aware that they could be prey for larger fish. Otos do a good job of hiding in plants and decorations, but due to their tiny size, they are still quite vulnerable.

For many fish keepers, a school of otos is a smarter alternative to a pleco. They are docile, super easy to care for, and appropriate for any fish tank where they won’t be eaten. As with other algae eaters, it is smart to feed algae wafers to ensure they are getting enough to eat.

Synodontis Nigriventris - The Upside-Down Catfish

Synodontis Nigriventris - The Upside-Down Catfish

5. Synodontis (Upside-Down) Catfish

The Synodontis or “upside-down” catfish is native to rivers and streams of the Congo region of Africa. They reach an adult length of around four inches and can be kept in a 30-gallon aquarium. However, because they are schooling fish that do best in groups of six or more I would suggest a 55-gallon tank or larger.

Upside-down catfish are among the most entertaining fish you can have in your tank. As their name suggests, they swim upside down. In fact, it isn’t uncommon for them to spend a great deal of time belly-up, without a care in the world. They are also skilled hiders and can be especially shy during daylight hours.

These are peaceful, easy to care for fish, and great for a community tank. Consider a planted aquarium with a lot of hiding spots. While they will scavenge and eat some algae, be sure to feed sinking pellets and algae wafers to supplement their diet.

6. Iridescent Shark Catfish

For me, the iridescent shark catfish represents my greatest error and biggest regret in my fish-keeping career. When I was new to the hobby, going on the advice of a pet store, I purchased a pair of these fish. They were about five inches in length, and I expected them to grow another few inches. They seemed like a great choice for my 55-gallon tank. Nope.

From the start, my shark catfish would glass surf constantly, to the point where they would somehow render themselves unconscious at times. I tried everything I could think of but they wouldn’t calm down. Back then there was no internet to speak of, so any help I could get was based on books, magazines, and hoping to run into someone who knew what they were talking about.

They eventually died, presumably of stress, stress that could have been avoided if I had been able to properly research this fish before purchasing. So, what went wrong?

These fish live in deep water in the wild, and they are schooling fish that need to be kept in groups. A larger tank and more of their kind probably would have helped to cut down on the stress. But, even then they would have been a terrible choice for a home aquarium.

That’s because iridescent shark catfish can grow to an adult length of four feet and weigh over 90 pounds! How big of an aquarium do you think you’d need to house a school of half-a-dozen fish, each four feet long and 90 pounds?

My guess is somewhere in the neighborhood of 1,000 gallons. So, unless you have a tank that large, you should avoid these catfish. They are really cool, but they are not appropriate for the home aquarium.

7. Pictus Catfish

The pictus catfish is a beautiful, active addition to tanks 55-gallons and bigger. They grow to an adult length of about six inches and are best kept in small schools. As with most catfish, it’s a good idea to consider a planted tank with hiding spots.

Pictus cats will scavenge for flake food that falls to the substrate and should be fed sinking pellets to supplement their diets. They also have a predatory nature, and this is one of those fish where you want to choose tankmates that don’t fit into its mouth. If you keep pictus cats and notice your neons vanishing, consider them high up on the suspect list.

Be aware that these catfish have very sharp fins. Of course, you shouldn’t be handling your fish anyway, but it is something to consider when working in your tank. It is also a good idea to remove them from a tank if and when necessary by using a cup instead of a fish net, to avoid getting their fins tangled and possibly damaged.

Siamese Algae-Eater

Siamese Algae-Eater

8. Chinese Algae-Eater

The Chinese algae-eater is another “suckerfish” known for cleaning up algae in aquariums. They grow over ten inches in length and become very aggressive as they age. In fact, as they age they tend to eat fewer algae and require sinking pellets for the bulk of their diet. If they can’t get the nutrition they need they may resort to attacking other fish.

I’d recommend the Chinese algae-eater for experienced fishkeepers who know what to expect and how to handle its behaviors. For most fish keepers, I think the oft confused Siamese algae-eater is a better choice.

The Siamese algae-eater is actually a species in the carp family, and so not quite similar to the other catfish in this article. They can live in schools with peaceful, community tankmates in tanks 55 gallons and bigger, and reach an adult length of about six inches. A planted tank with hiding spots is a good idea, and be sure to feed sinking pellets and algae wafers.

9. Striped Raphael (Talking) Catfish

The striped Raphael catfish is a peaceful bottom dweller that can grow to around eight inches in length. They are also called the “talking catfish” due to the croaking sounds they make. Like the pictus catfish, they are beautifully colored, do best as a part of schools in planted tanks, and may eat any fish that is small enough to fit in their mouth.

If you stock bigger fish the talking catfish make great community fish, and they are especially active at night. Like the pictus, be wary of their sharp fins while working in your tank, and transfer them using a cup or glass rather than a fish net.

10. Glass Catfish (a.k.a. Ghost Catfish)

The glass catfish, also known as the ghost catfish, looks about like what you’d expect. They have transparent bodies, making them unique on this list and unusual in the aquarium world. With their long barbels, they look almost like shrimp.

Glass catfish can grow to around five inches in length and do well in planted, community tanks. Keep them in schools of six or more, and consider a minimum tank size of 30 gallons, with 55 gallons preferable.

They are peaceful fish, and unlike most catfish, they spend most of their time in the middle of the water columns. For that reason, flake food is preferable to sinking pellets. You might also consider meatier foods like blood worms.

Even though they are not bottom-dwellers it is still a good idea to provide hiding spots in the form of plants and decorations.

These fish are somewhat fragile, and may not be the greatest choice for beginners. However, if you can keep them successfully, a school of glass catfish in a large, planted tank looks spectacular.

How to Choose Catfish for Your Aquairum

As you have read, it is very important to understand the care needs, size, and temperament of whichever fish you are interested in. I’ve already mentioned how catfish are often greatly misunderstood by beginners. Why is that?

The iridescent shark catfish commonly sold as four-inch juveniles in fish stores and has the potential to grow to four feet is not a beginner fish. In fact, that’s not a fish most advanced fish keepers would want to deal with in a home aquarium.

Other catfish like plecos can grow to a couple of feet, and others remain small enough to manage in large tanks, but big enough to eat many of the other fish in that tank. Still others become extremely aggressive as they age.

On the other hand, cories are among the best fish for beginners.

Catfish vary widely in their needs and behaviors. Hopefully, it is now clear why research is needed. When choosing catfish for your aquarium consider:

  • Tank Size: Is your tank large enough to house the fish as an adult?
  • Tankmates: Will the catfish get along with other fish in the tank? Will the other fish pick on or eat the catfish? Will the catfish eat any of the other fish?
  • Behavior: Is the catfish an aggressive species you should keep in a semi-aggressive setup or a peaceful fish you can keep in a community tank?
  • Tank Setup: Some catfish should not be kept in planted tanks, where some do best in planted tanks. Some require driftwood. Make sure your tank matches the needs of the new catfish.
  • Food: Is the catfish a scavenger, an algae eater, or both? You don’t want to overstock on either, so you can make sure everyone has enough to eat.

Hopefully, this article got you started with your research, and gave you a good idea of which type of catfish you might consider.

Types of Catfish

This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.

© 2019 Eric Dockett


Iraj Gardner on August 23, 2019:

Re the Siamese Algae Eater - first of all the pic you have is not a Siamese Algae Eater, it's an otoclinus (Chinese algae eater) species that looks very similar. The true Siamese Algae Eater has an iridescent yellow stripe above the black stripe, its back is more brownish, the scale pattern is more prominent (causing the edges of the yellow and black stripes to have a zigzag appearance) and the belly is white. I'm looking at my own specimen as I write this.

Secondly, the Siamese Algae Eater is NOT a good choice for a community tank. Like the Chinese, the Siamese starts attacking other fish as soon as it gets to about 5 inches in length, and loses interest in algae and plant matter. Mine has started chasing other fish and biting at their fins. They are fast swimmers and should never be kept with slow moving or long finned species such as Discus or Angelfish.

I feed both algae wafers and sinking shrimp pellets as well as thawed bloodworms, but the Siamese Algae Eater attacks my giant danios, rams and angelfish anyway and I will probably have to euthanize it soon. In the past I've seen Chinese and Siamese algae eaters eating holes in the sides of other fish if not removed as soon as they become aggressive.

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