Plecostomus, or Plecos, are a group of armored catfish that belong to the Loricariidae family.
They are by far the most popular catfish amongst fish keepers and in total there are well over 150 species.
The most in-demand member of this family is called the Common Pleco and can grow up to 24 inches long.
In our complete guide, we discuss the various species, care guide, tank mates, aquarium requirements and much more.
Want Something Extra? Download your free Plecostomus guide to learn all about their dietary needs, tank conditions and more.
|Color Form:||Brown, Gray|
|Size:||Up to 24″|
|Minimum Tank Size:||30 Gallons+|
|Tank Set-Up:||Freshwater: Driftwood and Caves|
|Compatibility:||Limited due to size constraints|
The Plecostomus catfish, or Pleco for short, is a name used for the catfishes that belong to the Loricariidae family.
In total there are more than 150 different species; ranging from small to large and peaceful to aggressive catfish.
You may have heard of the naming system (“L” or “LDA” followed by numbers) which is used to identify the various members of the Loricariidae family.
Whilst lots of beginner fish keepers think that the common Pleco refers to the Loricariidae family it actually refers to a specific member of the family; the Hypostomus plecostomus.
The common Pleco is the most popular freshwater catfish amongst fish keeping enthusiasts and is a type of armored catfish.
It is found in the freshwater streams and rivers of South America, can grow up to 24 inches in length and have a lifespan of 10-15 years.
The first thing to know about this fish is that it is nocturnal. This means during the daytime you won’t see much activity.
In the daytime, they can appear timid and you will likely find them hiding amongst the plants and any caves inside your tank.
When they are active you will notice that they are a bottom-dwelling fish and will move slowly across the floor of the aquarium.
Whilst moving slowly across the floor they make a superb job of cleaning up algae within the tank.
It’s important to note here that while they will eat algae, their diet should not be made up of that alone.
Many pet stores advertise them as algae eaters which is dangerous as they are omnivores and require other nutrition.
You will also notice here that they use their suckermouth and attach themselves to the glass or rocks within the aquarium.
Whilst they generally have a friendly temperament they do best in a tank on their own due to size constraints (read the tank mates section below for more).
Appearance of Plecostomus
The majority of Plecos are brown in color; however certain species’ coloration is dependent on their environment. The majority of them also have sand-colored spots or patterns.
They are referred to as “armored catfishes” because they have large boney plates that cover their body.
One of the most unique things about them is their mouthparts; this is what makes them so effective at cleaning algae.
As for their appearance; in the wild, they will grow to around 24 inches in length, in an aquarium this will only grow to around 15 inches.
Like other members of the family, they have an elongated body which covered with four rows of bone plates. The bone plates are not present on their abdomen.
They have well developed dorsal, pectoral and tail fins. The dorsal fin has one coarse ray and seven soft rays. The anal fin has one coarse ray and between 3-5 soft rays.
Its body is gray colored with brown spots and patterning. They have a large head with small eyes that are high up on their head.
Interestingly they have a membrane covering their eyes which allows them to control the light exposure into their eyes.
One of the most interesting things about this fish is its tail fin; it is moon-shaped, the bottom part being longer than the top.
Plecostomus Types (Species)
To date more than 150 different species of Plecos have been discovered, however, not all of them should be kept in an aquarium.
Below is a list of the most popular aquarium ones:
- Bristlenose Plecostomus (Ancistrus sp.)
- Gold Nugget Plecostomus (Baryancistrus sp.)
- Zebra Plecostomus (Hypancistrus zebra)
- Clown Plecostomus (Panaqolus maccus)
- Sailfin Plecostomus (Pterygoplichthys gibbiceps)
- Snowball Pleco (Hypancistrus inspector)
- Royal Plecostomus (Panaque nigrolineatus)
In the wild, a common Pleco will grow to around 24 inches, and in an aquarium, it will typically grow to around 15 inches.
Plecostomus Habitat and Tank Requirements
The majority of Plecostomus are native to South America. They can survive in a wide range of habitats, with the majority of them living in fast-flowing streams and rivers with a rocky substrate.
However, some can be found in brackish estuaries.
You should remember though that each species is unique and no two require the exact same habitat or tank setup.
So you should thoroughly research the needs of the specific breed you’re interested in keeping.
An example of this being aquarium sizes. Smaller Plecos (Otocinclus Catfish) can survive in a 10 gallon tank whereas larger species such as a Bristlenose needs a minimum of 25 gallons.
Now let’s look at the common Pleco and their specific requirements.
It’s important to note here, that they are usually only 2-4 inches long when first bought, grow very large, very quickly.
Therefore they are only suitable for more advanced aquarists in tanks of at least 80 gallons. As it grows, you’ll need at least a 150 gallon tank.
The Hypostomus plecostomusis native to the tropical waters of South America, specifically the Amazon River basin.
This natural environment consists of shallow streams and rivers that flow through tropical forests.
This water tends to be fast-moving and littered with driftwood and plants; you will find them hiding amongst them during the daytime.
So how does this translate in setting up an aquarium for Plecos?
Firstly, you should make sure that their aquarium has plenty of hiding places as they will sleep in these places during the daytime.
You can create these hiding places by adding caves and hollowed logs. You can also use upturned flower pots.
They also prefer a tank that is heavily planted. You should make sure these plants are hardy because they like to nibble on them.
Faster growing plants such as java moss are ideal. As mentioned in the dietary needs section (below) you should also make sure they always have access to driftwood to nibble on.
This combination of dense debris and vegetation helps to make them feel safe and secure.
Pleco Fish Tank Conditions
As previously mentioned they are fairly hardy fish so the water parameters aren’t as critical to maintaining when compared to other fish.
The most important thing is maintaining a strong water current and keeping it well filtered. For this, you should use good quality canister filters.
As for the parameters you should aim to keep the water temperature between 72°F and 86°F, with pH levels between 6.5-7.5.
The most important aspect of the water conditions is just to ensure you keep your water clean.
What Size Tank Do Plecostomus Need?
The common Pleco, it requires a huge tank. Once they reach an adult they need at least a 150 gallon tank.
As for other popular species here are their minimum tank sizes:
- Bristlenose Plecostomus (Ancistrus sp.): 25 gallons
- Gold Nugget Plecostomus (Baryancistrus sp.): 50 gallons
- Zebra Plecostomus (Hypancistrus zebra): 30 gallons
- Clown Plecostomus (Panaqolus maccus): 30 gallons
- Sailfin Plecostomus (Pterygoplichthys gibbiceps): 125 gallons
- Snowball Pleco (Hypancistrus inspector): 30 gallons
- Royal Plecostomus (Panaque nigrolineatus): 125 gallons
Plecostomus Diet and Feeding
As you already have known most are sold as ‘algae eaters’ which would have you believe that they are herbivorous; however, most of them are carnivorous and will eat smaller fish, invertebrates, and crustaceans. Whilst they won’t outright kill for meat they will scavenge making them ‘opportunistic’ omnivores.
Certain varieties also feed on wood, so make sure you thoroughly research the exact species you are interested in to ensure you meet their dietary requirements.
As for the Common Pleco, the common misconception is that they can live purely on algae. This is wrong and in fact, leads to malnourished fish that are unhealthy.
Their diet should be comprised of vegetables and algae; they will occasionally eat meat/live food.
Like always, we recommend that a high-quality pellet forms the basis of their diet.
For vegetables you can feed them: lettuce, zucchini, spinach, shelled peas and cucumbers to name only a few of their favorite.
For live foods: bloodworms, earthworms, crustaceans, and larvae. Our preference is the worms because they sink, meaning in a community tank the Plecos can still eat.
One important point to remember is that they require lots of fiber; feeding them a lot of vegetables helps them meet this requirement.
You should also make sure they always have access to driftwood to help with their digestion.
As for feeding habits, if you’ve read the typical behavior section above you will know that they are nocturnal.
So you will find they eat best during the evening just before you turn the lights in the tank off.
Plecostomus Tank Mates
The first thing to bear in mind is that this fish is nocturnal.
As a youngster, this fish is fairly peaceful and can be kept in a community tank. Some ideal tank mates include:
- And other common community fish
Even as juveniles you should avoid placing it with Discus and Angelfish as they are known to nip at them.
Bear in mind the usual rule – any smaller tank mates shouldn’t be able to fit in the Plecos mouth; if it can it won’t be long until its tank mate turns into dinner.
As it ages it will quickly outgrow other fish and should be kept in its own tank.
Can You Keep Plecostomus Together?
Whilst, in theory, you can keep them together, in practice it is near impossible due to the size constraints.
If you want to keep two or more together you would need at least a 300 gallon tank making this unreasonable for all but the most experienced fish keeper.
Unfortunately not much is known about breeding Plecostomus, and even less is known about breeding them in an aquarium.
What is known is that it is very difficult to breed them in captivity.
They are egg-layers and in the wild they generally spawn in caves, laying large volumes of eggs on flat surfaces.
The male will then guard the cave until the eggs have hatched. As fry they are known for being demanding eaters requiring large amounts of protein.
Is the Plecostomus Right For Your Aquarium? (Summary)
After reading this complete Plecostomus guide you should know if the common Pleco is right for you and your aquarium.
If you’re interested in other members of the Loricariidae family, we have already published the Bristlenose Pleco guide and are currently authoring more.
Whilst in principle they are easy to keep and don’t have any complex care needs, due to the size of the aquarium they need, it makes them unsuitable for all but the most experienced fish keepers.
This makes them a large commitment, so make sure it’s the fish for you before you decide to get one.
Let us know in the comments section below if you keep any Plecos…