Butterfly Pleco (L168) 101: Care, Max Size, Diet, And More!

As a fish keeper, you always look for new and interesting fish to add to your tank. If you’re looking for something truly unique, you should consider adding a butterfly pleco to your collection. These amazing fish are sure to get attention from anyone who sees them in your tank.

However, before you add a butterfly pleco to your tank, there are a few things you need to know. 

This guide will cover everything you need to know about butterfly plecos. You’ll learn about their habitat, size, diet, tank mates, and more!

Species Profile

The beautiful Butterfly Pleco (L168) was formerly classified into the genus Ancistrus with the scientific name of Ancistrus brachyurus by Kner in 1854. It has been moved around to a few different genera since then, including Zonancistrus and Peckoltia. Some shops still sell this fish under the Peckoltia pulcher, its former trade name.

But nowadays, it is considered a species of the Dekeyseria genus and known as the recognized name of Dekeyseria brachyura. The continuous debate is still going on over which genus this species belongs to.

Due to their particular shape, these fish have several common names, including Butterfly pleco (L168), Flunder pleco, L168 pleco, Brazil Butterfly Pleco, and Demini Butterfly Pleco in the aquarium trade.

Butterfly plecos (L168) originate from the lower Negro River basin in Brazil, more precisely, from the Demini River, a tributary of the Rio Negro. For this reason, most fish keepers simply refer to them as Demini Butterfly Pleco or Brazil Butterfly Pleco.

The origin matters because it is easily confused with its close relative L052 Butterfly Pleco (Dekeyseria picta), which come from the Orinoco River in Colombia and Venezuela and have a few subtle differences in terms of appearance. 

The Butterfly Pleco L168 grows larger than Butterfly Pleco L052, around 6.3 inches (16 cm) in length when fully grown, and has much larger odontodes. They also exhibit stronger, more contrasting markings with a bit more orange coloration. 

Scientific Name:Dekeyseria brachyura
Common Name:Butterfly Plecostomus
Care Level:Beginner
Origin:Rio Negro, Brazil, South America
Lifespan:5 to 8 years
Max Size:6.3 inches (16 cm)
Temperature:77 – 86° F (25 – 30° C)
PH:5.6 to 7.0
Water hardness:2 to 18 KH
Minimum Tank Size:40 gallons


L168 Butterfly Pleco

The Butterfly Pleco is one of the most striking Plecos that are kept in the aquarium compared to other plecos.

The species has the classic pleco shape with a flattened body and a large sucker mouth. Near the eyes, their body is slightly tapered and compressed towards the tail.

The butterfly pleco has a light/dark brown base color, with bold black stripes or butterfly markings covering its entire body, which gives this fish its name.

These markings provide excellent camouflage in the wild, helping the fish to blend in with its environment and avoid predators. If you keep them in aquariums with a black substrate and background, their base color and stripes will appear much darker, while in a lighter substrate, their colors will appear brighter.

Males Vs. Females

The easiest way to distinguish Butterfly pleco males from females is by looking at their odontodes.

Mature male butterfly plecos tend to have more prominent odontodes on their pectoral fins and cheeks than females. Their pectoral spines are longer that are used for defense and mating purposes.

Additionally, males are more slender while females are broader in shape when viewed from above. 

Butterfly Pleco Size & Growth Rate

Adult butterfly plecos (L168) can reach a maximum length of 6.3 inches (16 cm). Unlike many other popular plecos, they can be kept in smaller aquariums, making them a great pet for beginner fish keepers.

Butterfly plecos grow at a moderately fast rate. It takes them about 2 to 3 years to reach their full adult size.


The average Butterfly Pleco lifespan is around 5 – 8 years with good care. This assumes that you provide a well-maintained environment.

As always, there are no guarantees for longevity, and these fish can suffer from health problems just like any other pet.

Care & Tank Setup

Butterfly Pleco (Dekeyseria brachyura)

Butterfly Plecos (L168) are a tropical species. In the wild, they inhabit warm, acidic blackwater streams and tributaries. As you might know, the Rio Negro, or Guainía is the largest blackwater river in the world.

These fish are pretty hardy due to their varying natural environment, which means you have some wiggle room when it comes to setting up their tank. However, for optimal health, you should try to recreate their natural habitat as closely as possible.

Here are some things to keep in mind when setting up a butterfly pleco tank:

Butterfly Pleco Tank Size

Since Butterfly Plecos aren’t rather large and don’t require a large aquarium the same as common pleco, a 40 gallons long tank (48″ x 12″ x 16″) is big enough for a single fish.

If you want to keep a pair of butterfly plecos, you’ll need at least 75 gallons (48″ x 18″ x 21″) for them to be comfortable.

Like more bottom-dwellers, butterfly pleco may be territorial towards each other. A larger tank with more footprint gives you more decoration space so that you can create better boundary lines and territories for each fish.

Water Conditions

Butterfly plecos come from blackwater streams where the water is typically soft and acidic and stained a dark tea color from tannins released by decomposing leaves and wood.

While you don’t need to recreate these ideal water parameters exactly, here’s what you should aim for:

  • Water temperature: 77 – 86° F (25 – 30° C).
  • pH level: 5.6 to 7.0
  • Water hardness: 2 – 18 dGH
  • Ammonia: 0 ppm
  • Nitrite: 0 ppm
  • Nitrate: <30 ppm

Even though these water parameters are relatively forgiving, you should still do regular water tests to make sure that everything is in order. Get a quality water test kit and use it every couple of weeks to keep an eye on the ammonia, nitrite, and nitrate levels in your butterfly pleco tank.

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If you notice a sudden spike or decrease in any of the levels, take action immediately to fix the problem. Butterfly plecos are sensitive to ammonia and nitrites, so these levels should always be at zero.

Creating a moderately strong and consistent current in your aquarium is important and high levels of oxygen are necessary.

Decor & Substrate

Butterfly plecos often hang around the bottom of the tank, so you’ll want to make sure that there are plenty of hiding places to retreat to when they feel threatened or need some alone time.

Driftwood, rocks, and caves are all great choices. Just make sure the rocks are flat, so they can easily suck on. Driftwood or bogwood is crucial for the health of your butterfly pleco as it helps maintain the water chemistry and serves as a plant source for them to aid their digestion.

As we mentioned, these fish can change their body colors to stay camouflaged with their surroundings, so a lighter substrate is ideal for clearly showing off their stripes. Soft pool filter sandy or fine gravel would be perfect.

They will normally leave your live plants alone unless there is no other vegetable source, in which case they may nibble on soft-leaved plants. If you want to keep live plants in your butterfly pleco tank, choose species that are too tough for them to eat.

Food & Diet

Although Butterfly plecos are omnivorous, they primarily eat algae in the wild.

In captivity, you can’t rely on algae alone to provide all the nutrients your butterfly pleco needs, so you’ll need to supplement their diet with other foods.

A good quality pleco diet pellets or wafers should form the basis of their diet, but you should also offer them a variety of fresh vegetables. Zucchini, cucumber, carrots, and spinach are all great choices.

You can also give them the occasional treat of live or frozen foods, such as bloodworms, brine shrimp, or daphnia. Just ensure you don’t overfeed them as this can lead to health problems.

Because this fish is a nocturnal species, they are most active at night. So, it’s best to feed them before you turn the lights off for the evening.

Butterfly Pleco Tank Mates

Since the butterfly pleco (L168) is a peaceful and friendly fish, it can be kept with most other non-aggressive freshwater species.

However, it can be territorial towards other members of its own kind and may even attack fish that resemble plecos in shape or appearance. It rarely shows serious aggression towards other fish, but males may nip and chase each other if it feels threatened.

Some possible butterfly pleco tank mates include:

Butterfly Pleco Breeding

Breeding butterfly pleco is something challenging, but it is definitely possible. It is difficult to breed them in captivity because they are not common in the aquarium trade and need a very specific type of environment to feel comfortable enough to lay their eggs.

If you are familiar with breeding Bristlenose pleco, then you may have some success with butterfly pleco as well. They are very similar in their breeding habits. I highly recommend reading our Bristlenose pleco breeding and eggs and babies care guide if you want to learn more about them.

Butterfly plecos are cave spawners, meaning they will lay their eggs in a cave or some other type of sheltered area. If you want to encourage breeding, you should provide them with plenty of hiding places and pleco caves in the tank.

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It’s best to house a group of juveniles together to get them to pair off and start breeding. Once a pair has been formed, you should move them to a separate breeding tank with the same water conditions and decoration as the main tank.

The female butterfly pleco will lay eggs in the cave, which the male will then fertilize. Once the eggs have been fertilized, the male will be solely responsible for guarding and fanning the eggs until they hatch, which usually takes about 7-10 days.

The fry will be very small when they first hatch and will need to be fed baby brine shrimp. As they grow, you can start feeding them regular pleco food such as algae wafers and zucchini.


Now that you know how to care for butterfly pleco, you should be able to decide whether or not this is the right fish for your aquarium.

These beautiful and interesting fish are a great addition to most South American community tanks. They are peaceful and easy to care for, as long as you provide them with the right type of environment.

Unlike L052 Butterfly plecos, L168 butterfly plecos are not commonly seen in the trade. But they are sometimes available online or through specialty fish stores at a higher price. If you are looking for a butterfly pleco for your aquarium, be prepared to pay a little extra for one of these fish.

As always, we welcome any suggestions or comments that you may have about butterfly pleco care. We’re dedicated to providing you with the most comprehensive care guides, so feel free to drop us a line if there’s anything you’d like to know that we haven’t covered. 

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