Home > Tips & Tricks > L333 Pleco Care Guide: Breeding, Diet, Behavior & More

L333 Pleco Care Guide: Breeding, Diet, Behavior & More

The L333 is a very appealing pleco type for many aquarists. Unlike the popular common pleco, this species stays relatively small and is rather docile. When it comes to ‘fancy plecos’, it’s rightly one of the more popular types!

Scientific nameHypancistrus sp.
HabitatRio Xingu River, Brazil
Size<6 inches
TemperamentMostly peaceful, can be shy
Tank size>30 gallons
DietMainly carnivorous, some plant-based foods can be fed.
Water temperature79-86° F (26-31 °C)

This article is a guest post by Thijs from Keeping Catfish.

What are L-numbers?

To make identification easier for us aquarists, German magazine DATZ created a way to identify different types of popular Plecostomus catfish before they were officially described or given their own scientific names.

The main reason for this is that there are many different Pleco species that consist of multiple separate wild populations, which all have their own characteristics and may look slightly different from one another. As a result, it can sometimes be difficult to tell whether a certain Pleco is a new species or a variant of a described species. This is also why some species have multiple L-numbers: science is often just slower than the aquarium hobby. It takes time to get around to describing a species.

Until it is given an actual scientific name, this particular Pleco was given the L-number of 333, with the L being short for Loriicaridae (the overarching family these catfish belong to). Because this system is very convenient, it’s often still used even after the fish has been officially named.

The L333 Pleco in the wild

L333 Plecos originate from the Rio Xingu in the Amazon basin, around Porto de Moz, Brazil. The species can be found in fast-flowing river beds, which usually consist of rocks and sand on the bottom. Plant growth in these habitats tends to be sparse.

L333 Pleco appearance

This species is not among the larger Pleco catfish, only growing to around 6 inches in length. Some localities tend to stay even smaller, reaching barely 5″.

The normal pattern of this species consists of lines that run across the body. However, keep in mind that it can differ a lot in appearance, such as the amount, color and thickness of the body lines. This mostly depends on the locality where it’s naturally found:

  • Porto de Moz: broader lines, brighter yellow
  • Xingu: this variant is the most common 
  • Boda Seda: thinner, more yellow lines
  • Alenquer: thinner, more faded lines

The L333 is easily confused with a variety of other L-numbers, such as the L066, and it can be hard to recognize this species if you’re not an expert. There are also quite a few hybrids available. Make sure to go to a reputable breeder or seller to ensure you get a real L333

L333 Pleco care

Although the L333 is a fancy Pleco type, it’s still a rather easy species to take care of. As long as you meet their basic requirements, your fish will be happy and possibly even breed.

Tank setup

Setting up a tank for this species is similar to the process of setting up a tank for other Plecos. This species can be kept in a community tank, but thrives when kept in a species-specific set-up.

If you want to breed your L333s, a dedicated breeding setup is recommended.

Tank size

The minimum tank size to maintain small Plecos like these is 40 gallons, in which a group of 4-6 animals can be housed.

For breeding purposes, a smaller tank could be set up, upwards of 30 gallons. Have a look at the section regarding breeding L333 for more about getting your Plecos to multiply!


In the wild, this species lives on a sand-gravel substrate with rocks larger rocks providing shelter. To mimic this natural habitat, sand or fine gravel is perfect. Unlike something like the popular Corydoras catfish, which has a strong preference for sand, the L333 pleco is flexible and does fine on most substrates.

You can also choose to keep your Plecos in a so-called bare-bottom tank. This is a tank with no substrate, which makes it easier to keep things clean. I prefer to use this method in breeder setups or grow-out tanks. 


Plecos prefer a tank with low to medium lighting and this is no different for L333. Even though Pleco catfish are not nocturnal animals, they will not feel comfortable in very bright light. 

The best way to keep the lighting friendly is by adding floating plants such as Amazon frogbit. If you do have bright aquarium lights, it’s best to add plants with large leaves (e.g. Amazon swords) and plenty of hiding places to create shade.

Décor & Plants

Hiding places are essential for L333 pleco catfish. Ironically, adding more hides will cause your Pleco to be less shy and come out more. It will feel like it can dart back into hiding at any time, making it feel safer.

The L333 doesn’t need driftwood as part of its diet as some Pleco catfish do, but it makes for a good natural hiding spot nonetheless. Stones are also great, but be wary of rocks with high calcium content, as those can alter the water consistency in your aquarium.

Did you know? If you want to go the extra mile, Pleco caves are one of the best ways to provide natural cover. In fact, these caves are great for breeding your Plecos, too. For L333, a cave with a length of approx. 6 inches and a diameter of around 1.5-2 inches is perfect.


The L333 is used to life in rivers with clean and fast-flowing water. Since plecos are big polluters (yep, they poop a lot!), a strong filter is of big importance if you want your L333 to thrive. You’ll also have to do plenty of water changes in order to keep the water quality high.

I recommend a canister filter that filters 6-10x the volume of the tank per hour. This ensures that the water quality remains high, which is essential. Ideally, you’d point the filter outlet in such a way that it causes a good level of flow throughout the whole tank.

Optionally, you can use an airstone connected to an air pump, to add more oxygen to the water. This can also be in the form of a sponge filter, through which you add an extra layer of biological filtration.


This type of pleco is not aggressive and can live with many other fish. In fact, it’s very beneficial to keep fish that live in other water levels of the water column (middle and top), because it will make your Pleco feel safer. If there are no fish swimming above the Plecos, they can end up feeling stressed, thinking that everyone fled because there are predators coming. 

On the other hand, there can’t be too much competition in the bottom layer of the tank. Plecos can become quite territorial, and they do need their space. Calmer species like Corydoras catfish or kuhlii loaches can certainly work, but too much competition can cause conflicts for food and hides.

Most species of rasboras and tetras are great and will leave your L333s alone. Stay away from aggressive feeders, as they will outcompete the Plecos for food.

The L333 Pleco can be housed solo or in groups. Make sure to provide at least one hiding spot, such as a cave, per fish (including females).

Water parameters

The L333 pleco originates from the Amazon rainforest, and prefers soft and acidic water with a pH of 6-7.5. Wild-caught fish tend to be more sensitive to less than ideal water quality, and will prefer water parameters closer to those in their natural habitat. 

The species’ preferred water temperature is 79-86 °F (26-31 °C).

Don’t forget: to maintain low nitrite and nitrate levels in the tank, weekly water changes of 50% are needed. A filter alone is not enough to keep the water quality high. You should perform regular water tests using a liquid test kit to ensure everything is still in order.

L333 Pleco diet

The L333 pleco is a mainly carnivorous fish. To keep yours well-fed, consider foods like carnivore pellets, Repashy’s meat-based options, and frozen foods. It’s important to vary between different types of food, to ensure your pleco receives all the nutrients it needs.

Unlike many other pleco species, the L333 pleco will not eat wood or any vegetables. You could occasionally try feeding something like spirulina tabs to provide yours with some of the useful nutrients this alga contains.

Breeding the L333 Pleco

Breeding setup

In order to breed this species, it’s recommended to set up a dedicated tank for this purpose. This tank should contain a bunch of Pleco caves, which can’t be confused with other types of decoration you’d find at the fish store. Pleco caves are specially designed to breed Plecos, and it will be far easier to do so if there are enough of them in the aquarium.

The males will each conquer their own cave, which they will spend almost all of their time sitting in. If you have multiple males, the alpha male will take the best cave. To avoid conflict, add at least one cave for every fish, organized in different ways. The females like to change caves and wander around the tank. 

Sexing the L333

Sexing this type of Pleco is only possible when the adult animals are fully grown and sexually mature. If the fish are well fed, it’s actually fairly easy to sex this species.

When viewed from above, females will have a plumper and more round body shape, while males look more triangular. The same goes for their heads. Very mature males can grow odontodes (bony protrusions) on the base of the tail and pectoral fins.

Did you know? It’s best to keep one to three females per male for breeding purposes. 

Breeding process

When the pair is ready for breeding, the female will begin to hang out more around the cave owned by whichever male has caught her eye. Eventually, she’ll enter the male’s cave, and he will trap her. The female can stay inside the cave for days, laying between 30 and 50 eggs. The male will then fertilize the eggs and subsequently kick her out rather unceremoniously.

After mating, the male will guard the eggs and fry for around two weeks. The eggs themselves take 5-10 days to hatch, and the fry will live off of their yolk sacks for around a week before exiting the cave. 

Getting Plecos to spawn

In the wild, the L333 Pleco will spawn during the rainy season. This is why naturally, L333 Plecos will spawn when a rain storm is happening outside (low air pressure).

So how do you get these guys in the mood? First off, it’s important to condition your adult fish by heavily feeding them with a variety of foods. These can be frozen foods, but the best would be live foods such as blackworms or mosquito larvae.

After this, Plecos can be triggered to spawn by simulating rain. This is done by means of performing water changes with rainwater, which has a lower pH. The key with these fish usually is patience, and multiple water changes might be needed to reach success.

Raising the fry

Pleco fry can perfectly survive on their own in the adult tank, as long as there aren’t any predatory fish present. They can eat the same food as the adults, meaning that raising them can be a pretty low-maintenance affair.

However, for the best results, it’s best to move the fry (just before they leave the cave) to their own dedicated grow-out tank. This way, you can feed them directly, as well as monitor them more easily. In terms of diet, the fry will love the same foods as adults, but frozen and live foods will need to be chopped up.


The L333 is a great fish for aquarists who want a type of fancy Pleco, but are worried about shelling out big bucks for a fish that’s very difficult to keep alive. L333 does need a little more attention than the classic bristlenose Pleco (Ancistrus cirrhosus), especially if you were to breed them, but they aren’t as challenging as many other L-numbers.

To sum things up:

  • Unlike the bristlenose Pleco, this species is mainly carnivorous and should be fed a variety of meat-based foods. This can be pellets, frozen and live foods or Repashy. 
  • You can keep the L333 in a community tank, as long as there are no aggressive fish species present.
  • For breeding purposes, it’s best to move the fish to a dedicated breeding tank. In this set-up, there should be many breeding caves available. 
  • The fish are triggered to spawn by low air pressure and water changes. Before making a breeding effort, the fish should be conditioned with live and frozen foods.
  • Lastly, when buying this species it’s important to buy it from a reputable breeder or seller. This ensures you buy a real L333, not a hybrid, which are considered by some to be a big problem in the aquarium hobby.


  • Wikipedia – L-number
  • AquaMalik – Youtube – L333 King Tiger Pleco – Care and Maintenance info!
  • Aqua Info – Hypancistrus sp.
  • PlanetCatfish – L333
  • Aqua-Fish.net – L333 Pleco – The Tank and Proper Care & Forum
  • Seriouslyfish – Hypancistrus sp. – L333
Photo of author

Marijke Puts

Hey! I'm Marijke, FantaSEA's resident blog writer. I'm a full-time pop science author, part-time PADI diver and snorkeler, and have been keeping fish since I was a kid. When I'm not writing fish care guides, you can usually find me underwater or trying to figure out how to fit more tanks into my house.

Leave a Comment