Catfish are an extremely diverse group of fishes and many of them fare well in the home aquarium. Keep reading to learn about the most popular catfish for freshwater tanks.
When you think of catfish, you probably picture the big river fish you fry up and serve with a side of cornbread. When it comes to aquarium catfish, however, there are many different species. In fact, catfish can be found in almost every ecological niche around the world (except Antarctica). Some catfish live in oceans but, of the more than 2,400 varieties, most of them are freshwater fish.
If you’re looking for a bottom-dwelling species to add to your tank, catfish might be a good option. Keep in mind that because there are so many species, they come in different sizes and have different preferences for tank parameters.
Keep reading to learn about the most popular species of freshwater catfish and how to care for them.
What Makes Catfish Such a Popular Choice?
There are many reasons to love catfish in the freshwater aquarium. For one thing, they are an extremely diverse group of fishes with many unique colors and patterns. Catfish also tend to be very hardy and, for the most part, easy to keep in the home aquarium. There are exceptions to the rule, of course, but most of the popular species are peaceful fish that get along well in community tanks.
Catfish belong to the order Siluriformes which is a varied group of ray-finned fish. Most catfish have barbels on their faces which look similar to a cat’s whiskers. Because catfish have very small eyes, they rely on these barbels to navigate and to find food – they also have chemoreceptors all over their bodies which essentially “taste” the water around them. In terms of feeding habits, catfish range from herbivores (plant-eaters) to detrivores (fish that scavenge on decaying matter). There are also predatory catfish, but they generally aren’t recommended for the home aquarium.
Most catfish have cylindrical bodies with flattened bellies so they can swim easily along the bottom of the tank. They generally have large heads and wide, toothless mouths. Rather than biting or cutting through food, most catfish feed through suction – they essentially filter their food up through the substrate at the bottom of the tank.
In terms of size, catfish can vary quite a bit. Some of the smallest catfish you’ll find in the freshwater aquarium are Otocinclus Catfish, some species of which grow to no more than an inch long. On the other side of the spectrum, one of the largest species of catfish is the Mekong Giant Catfish (Pangasianodon gigas) which grows up to 10.5 feet long. Most freshwater aquarium catfish stay under 12 inches at maturity but, again, there are always exceptions to the rule.
Tips for Keeping Catfish in Your Aquarium
For the most part, catfish are not dangerous to humans – especially the species you would keep in your home aquarium. There are, however, some challenges you may encounter in keeping catfish in your tank. One thing many aquarium hobbyists fail to realize is that some species of catfish are nocturnal – they only feed at night. This means that they’ll be shy during the day and will need a place to hide. If your tank is too brightly lit, your catfish may not be active and may not thrive.
Something else to keep in mind is that while some catfish are considered armored with thick scales (such as Corydoras Catfish), others have no scales at all. This makes them particularly susceptible to changes in water chemistry. You’ll need to maintain very high water quality in your catfish tank and you should check your tank parameters often to ensure that they’re within the proper range. Invest in a good water test kit and keep track of your measurements so you can spot a problem quickly and make the necessary adjustments before your catfish suffer.
The Top 10 Most Popular Freshwater Catfish Species
Now that you know a little more about freshwater aquarium catfish and what makes them a good choice, you may be wondering which species are the best to keep. Here is an overview of the top 10 most popular catfish for freshwater tanks:
1. Bristlenose Pleco (Ancistrus cirrhosus) – Also known as the bushy-nose catfish, this species has a neutral brown coloration with lighter colored spots that enables him to blend well with his surroundings. These fish have been known to sit motionless for hours but they are still capable of doing quiet an efficient job with clearing your tank of algae. Bristlenose Plecos will eat most types of algae from any surface in the tank – they've even been known to worm their way into filters.
These fish grow to about 3 ½ inches in length and they have a peaceful temperament which makes them a good choice for community tanks. While juveniles are a bit sensitive to changes in pH, adult Bristlenose Plecos are fairly hardy which makes them a good choice for novice aquarium hobbyists. Though they will feed on algae, they don’t tend to harm aquarium plants and they will appreciate a supplemental diet of fresh vegetables and spirulina tablets or wafers.
2. Gold Nugget Pleco (Baryancistrus sp.) – One of the most colorful catfish on this list, the Gold Nugget Pleco has a dark brown or black body with bright yellow spots and yellow edging on the dorsal and caudal fins. This species is peaceful by nature so they do well in a community tank. They are also easy to feed due to their omnivorous diet and the fact that they aren’t very finicky. In addition to feeding on algae in the tank, they’ll also eat fresh veggies, algae wafers, and various meat-based sinking foods.
The Gold Nugget Pleco can grow fairly large (up to 10 inches), so you should keep that in mind. They require at least a 50-gallon tank and they are moderately easy to care for. Just make an effort to keep the water quality in your tank high and ensure that your Gold Nugget Pleco gets a widely varied diet to meet his nutritional needs.
3. Corydoras Catfish – A wonderful group of fishes, Corydoras Catfish are a delight to keep in the home aquarium. These bottom-feeders are very peaceful and most species don’t grow to more than 2 or 3 inches long. Corydoras Catfish, also known as Cory Cats, are best kept in schools of 6 or more and they come in a wide range of colors and patterns – there are even albino Corydoras. Some popular species of Corydoras Catfish include the following:
Peppered Corydoras (Corydoras paleatus)
Sterba’s Corydoras (Corydoras sterbai)
Emerald Corydoras (Corydoras splendens)
Panda Corydoras (Corydoras panda)
Adolfoi Corydoras (Corydoras aldolfoi)
Skunk Corydoras (Corydoras arcuatus)
Schartzi’s Corydoras (Corydoras schartzi)
One thing to keep in mind with Cories is that they spend most of their time on the substrate sifting for food. This means you’ll want to choose softer substrate that won’t scratch their soft underbellies or damage their barbels – sand is usually the best option. You’ll also want to keep the tank parameters as steady as possible and feed your Cories a varied diet of plant- and meat-based foods.
4. Upside Down Catfish (Synodontis nigriventris) – Aptly named, Upside Down Catfish actually swim upside down. Though they are capable of swimming normally, these catfish typically swim and graze upside down. These catfish are similar in body shape and size to Corydoras Catfish and they too prefer to be kept in small schools with 5 or 6 of their kind. This species prefers planted tanks (particularly broad-leafed plants) and they’ll help control algae growth.
In terms of their care level, Upside Down Catfish are relatively easy. They are also very peaceful fish that do well in a community tank. One thing to keep in mind with this species is that they are omnivorous – they won’t thrive if all they have to feed on is algae. This species needs a mixture of plant- and meat-based foods, so throw in some algae wafers and meat-based sinking pellets or wafers.
5. Glass Catfish (Kryptopterus vitreolus) – These fish look very different from the typical catfish. Not only are their bodies laterally compressed, but their bodies are completely transparent. Also sometimes known as Ghost Catfish, these fish make an excellent addition to the community tank as long as you have room for a small school of 5 or 6. If you keep these fish alone, they will become reclusive and may succumb to stress.
Glass Catfish are also unique in that they require low to moderate lighting – bright lighting will stress them out. This means that these catfish may not be a good choice for planted tanks that require a lot of lighting unless they have plenty of places to hide. Glass Catfish are also very sensitive to changing water conditions, so maintain stable water chemistry in your tank and keep the temperature fairly high (in the high 70s is best). This species is omnivorous and requires a varied diet.
6. Pictus Catfish (Pimelodus pictus) – This species of catfish is easy to identify by its long antennas as well as its light silver coloration. Pictus catfish are peaceful fish by nature and can therefore get along well in a community tank – just keep in mind that they are omnivorous and may eat the occasional fish if it is small enough to fit in its mouth. Generally speaking, Pictus Catfish enjoy a varied diet of flake foods and freeze-dried meat-based foods.
The Pictus Catfish is one of the larger species on this list, growing up to 5 inches long. These fish prefer to be kept in schools of 4 or 5, so make sure your tank is large enough to accommodate that need if you choose this species. Pictus Catfish can also become somewhat aggressive as they grow, so keep an eye out for that if you keep a whole school of them – make sure your other fish have plenty of places to hide, if they need to.
7. Otocinclus Catfish – Technically a genus of catfish, otocinclus are native to South America and they tend to stay very small. The smallest species, Otocinclus taprirape, tops out at 2.4cm while the largest species, Otocinclus flexilis, grows up to a maximum of 5.5cm. These catfish may be small, but they have a big appetite for stubborn algae and their size enables them to fit into even the tiniest cracks and crevices. This species is particularly recommended for planted tanks because they won’t damage plants – they do, however, like having algae wafers and fresh veggies to snack on.
In addition to being small enough for beginner tanks, Otocinclus Catfish are also relatively easy to care for. They do require high water quality and plenty of flow, but they can tolerate small fluctuations in tank parameters. These fish are very peaceful and will get along with other species just fine as long as they are not predatory fish. Just make sure your Otos have places to hide when they want to.
8. Clown Plecostomus (Panaqolus maccus) – The Clown Pleco is one of the smaller species of catfish on this list, growing only 3 to 4 inches at most. Because they feed on algae, however, they still need plenty of tank surface area. Keep in mind that this species prefers to feed on driftwood, so make sure you include that in your tank décor. In addition to driftwood, these catfish will appreciate having fresh vegetables and algae wafers in their supplemental diet.
Clown Plecos are peaceful fish that can get along in a community tank quite well. They are moderately easy to care for – it is really just their feeding habits that can be a challenge. Because their diet is widely varied, you can’t rely on your Clown Pleco to completely clean your tank of algae – you may want to add another species or some kind of community-friendly algae eater to your tank as well.
9. Bumblebee Catfish (Microlanis iheringi) – Native to South America, the Bumblebee Catfish is known (and named) for its yellow and black markings. These fish remain fairly small, growing no more than 3 inches in length. They are generally very peaceful, but they are an omnivorous species that has been known to eat small tankmates. These catfish require supplemental feeding with sinking pellets and meaty foods like brine shrimp or bloodworms.
Bumblebee Catfish are easy to care for as long as their dietary needs are met, and you keep them with other fish equal to or larger in size. These fish can be kept in planted tanks and they enjoy having places to hide such as rock caves and piles of driftwood. They can be kept with other peaceful catfish including Corydoras Catfish and they prefer warmer tank temperatures in the mid- to high-70s.
10. Whiptail Catfish (Dasyloricaria filamentosa) – This fish look like a flattened version of the Common Pleco with a longer tail. They are black or tan in coloration so they blend well with their surroundings and they grow fairly large, up to 6 inches in length. Whiptail Catfish are peaceful and can be kept in community tanks, though they do require a neutral pH so make sure the other fish you keep have similar requirements for tank parameters.
Whiptail Catfish are omnivorous, so they’ll need supplemental feeding with algae wafers and meaty foods in addition to feeding on tank algae. These fish have been known to breed in the home aquarium, as long as they have rocks and broad-leafed plants on which to lay their eggs. This species does require high water quality with plenty of aeration and they do particularly well in planted tanks. They also require hiding places so they don’t become stressed.
A Word of Warning
Though many catfish species do well in the freshwater aquarium, there are certain species that are more trouble than they’re worth. Unfortunately, many novice aquarium hobbyists make the mistake of adding these fish to their tank without doing their research first. Here are three common catfish species you should definitely think twice about before adding to your tank:
1. Common Plecostomus (Hypostomus Plecostomus) – This particular species isn’t necessarily a bad addition to the home aquarium, but they do come with certain challenges. While they may eat algae when they are young, many Common Plecos become lazy as they get older and they stop doing their jobs. The main problem, however, is their size – these fish can grow to over 2 feet long. Don’t fall for the myth that a fish will only grow as big as his environment – Common Plecos can quickly outgrow a small freshwater aquarium. If you want a pleco, choose a Clown Pleco or Bristlenose Pleco instead.
2. Red Tailed Catfish (Phractocephalus hemiolipterus) – These catfish are very attractive with their red and yellow coloration, but they come from the Amazon River which should be a clue about what their biggest problem is – their size. This species of catfish can grow to nearly 5 feet in length which is way more than even the most experienced aquarium hobbyists can handle. Unfortunately, these catfish are commonly sold in pet stores and sold to unsuspecting aquarium hobbyists. If you’re looking for color, try an albino pleco or a Bumblebee Catfish.
3. Tiger Shovelnose Catfish (Phseudoplatystoma faciatium) – This species of catfish is very unique in appearance because it has tiger stripes and a long, tapered nose. What many aquarium hobbyists do not realize is that not only can they grow over 40 inches long, but they are also a predatory species of fish. Tiger Shovelnose Catfish can grow very quickly depending how often they are fed and they will likely eat any other fish in the tank small enough to fit in their mouth.
With so many species to choose from, you can easily find a catfish that will work well in your freshwater aquarium. Before you buy, just be sure to do your research to ensure that the species you pick won’t outgrow your tank and that it won’t cause trouble for your other tank inhabitants. The information provided in this article should be more than enough to get you started. Good luck!
Also known as oto cats, otocinclus catfish are some of the smallest aquarium fish out there and also some of the best algae eaters.
FRESHWATER AQUARIUM ARTICLES
STOCKING THE TANK
The fish you choose to stock your tank is not a decision that should be made lightly. The articles in this category will help you understand the basics of fish compatibility and will provide you with other information you need to make an informed decision when stocking your tank.