Royal Pleco belongs to the catfish species from the category of armor-plated catfish due to the bony plates on its body.

They have a mouth under their face and have a ‘sucker-like structure’ that helps them stick on the surface and rasp on food material.

Many people keep them in the tank as they are also good cleaners.

Royal Pleco has many subspecies, such as Panaque ambrusteri, Thunder Line Pleco, White-tailed Royal Pleco, Watermelon Royal Pleco, Peruvian Green Royal Pleco, Broken Line Royal Pleco, Papa Royal Pleco, etc.

Details About Royal Pleco

Species Facts
Scientific Name Panaque nigrolineatus
Other Common Names Royal Panaque, Red-Eyed Royal Pleco, Royal Catfish
Family Loricariidae
Origin Amazon & Orinoco Basins (Brazil, Venezuela & Colombia)
 Average Lifespan 10-12 years (more in captivity)
Max. Length (average) 17 inches
Type Peaceful

Where Are They Found?

Royal Plecos are freshwater catfish, and they are native to South America.

They are found in Orinoco River to the southern parts of the Amazon Basin in Brazil, Venezuela, and Colombia.

How Long Do They Live?

Royal Pleco can live long and grow to quite a size like other catfish. They have been known to have an average lifespan of 10 years.

If they are kept in ideal tank conditions, they can surpass that and live up to 12 years. Even though they live long, unfavorable conditions may result in not surviving that far.

Size & Appearance

The typical mouth structure of Royal Plecos fetches them the name “suckermouth armored catfish.”

They can grow up to 17 inches as their maximum size in suitable tank conditions.

Royal Pleco Size & Appearance

Their body has a light grey to gunmetal color with dark grey or black striped patterns, which can be irregular and varies from individual to individual.

They have bright red or reddish-orange eyes, and the body doesn’t possess any scales. The bodies are pretty streamlined and curved at the top to let the water flow over them smoothly.

The dorsal fin appears like a giant sail of a ship and has spikes protruding out from them to protect themselves from predators. They aren’t fast swimmers and have no other ways to protect themselves.

How to Tell if it’s a Male or a Female?

It isn’t easy to distinguish between male and female Royal Pleco just by looking at their appearance. Both look strikingly similar to each other. It takes a few years for them to become adults, and even then, it’s difficult to tell.

Identification of sex is possible by carefully observing the papilla, which is present behind the anus of fishes.

The papilla in male Plecos is sharp and pointy, and in females, it is blunt and round. The male papilla is a bit smaller than the female even though it is pointed.

It is still unclear if this method can be used to determine their sex because they attain sexual maturity when they are at least 12 inches long, and still, it is hard to determine using external features. Features become clearer after they are fully grown.

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Author Note– Sometimes the male seems to have a chunkier body overall from top to bottom. The females have a thicker body in the middle, which is more tapered at the tail section. This identification for sexing is used sometimes but is still not reliable, so always use an expert’s opinion.

Availability and Price

Generally, it is uncommon in local stores to keep Royal Plecos as it is hard to come by but still can be found in most online stores. Most of them are not bred, instead caught in the wild.

Its price depends upon the size and age. They sell somewhere around $30 to $40, but bigger sizes can go up to $80 to $120.

Care Guide

Quick Care Facts
Care Level Intermediate
Breeding Difficult
Social Temperament Harmonious
Diet Omnivores but mainly Herbivore

What do They Eat?

These are freshwater fish, so their habitat has an abundance of oxygen, algae, and driftwood which they like to latch onto and slowly consume.

Royal Plecos are the only family of catfish that mainly feed on wood. Their suction-like mouth stick to the surfaces, while the spiny curved teeth can comfortably scrape it off from the logs.

Even though they may sometimes ingest fish food like-

  1. pellets
  2. flakes
  3. tablets
  4. wafers
  5. frozen food

They sometimes ingest bacteria and fungus, so their diet is quite varied but revolves around a vegetarian platter.

Quick Tip– Whatever diet you want to maintain, just remember that they naturally are interested in eating wood.

Temperament & Behaviour

Royal Plecos are generally peaceful fish. You will see them staying idle for long periods.

They sometimes get territorial if two are kept together in a tank, especially if the tank is small. They can sometimes become aggressive towards small fish, but it is doubtful.

There is little competition for food, but with other plecos, they share the same food source.

They are bottom dwellers but are sometimes seen adhering to the tank’s walls.

Mating & Breeding

How to Breed Royal Pleco Fish

Breeders and aquarists face a lot of problems breeding Royal Plecos in captivity. The reason behind it is unknown. More research and studies are required to find out the exact reason why Royal Plecos easily breed in wild but not in captivity.

But if you have managed to find a mating pair, it is advised to shift them to a different tank to avoid any kind of disturbances during the process. Try to imitate their natural habitat as much as possible.

They prefer softer water with slightly acidic pH during the breeding season. In the wild, the rain does this work for them.

When the spawning starts, the male stimulates the females to spawn the eggs, and the male fish guards the eggs till they have been fertilized.

After mating remember to transfer the parents back to their original tank so that they don’t accidentally eat their own eggs or fry-sacs.

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Quick Tip– It is recommended to put a Vinewood in the tank during mating as it is like a gourmet food for them. It improves their mood during the mating process.


Catfish species are naturally resilient against diseases, and the same is with the case of Royal Plecos. But still, they can be susceptible to a few freshwater fish diseases like:

  • White Spot Disease (Ich or Ick)
    The leading cause of this disease is a freshwater protozoa known as Ichthyophthirius multifiliis. Tiny white spots (1mm in diameter) appear on the body of the fish, and each white dot is a parasite. If not treated early, it can lead to death.

    Treatment– Specific antibiotics and bath salts are used to treat them. Zinc-free malachite is also used to prevent the further spreading of this disease.

  • Mycosis (Fish Fungus)
    Fungal growth on the fish body appears like cotton balls due to the fungus Saprolegnia. They should be treated as fast as possible since the fungus can spread very quickly.

    Treatment– Antifungal medication and bath salts are the best way to treat it. Also, it would be best if you moved the fish to another tank, so it doesn’t spread to other fish.

  • Dropsy
    Unhygienic tank conditions can lead to dropsy in them, which is hard to detect as Royal Plecos stay idle most of the time. But if it is inactive for a long time and appears bloated, chances are it’s suffering from dropsy.

    Treatment– Transfer to a hospital tank and treat the water with Epsom salts to relieve fluid pressure inside the fish. You can treat them with antibiotics if it’s caused by bacterial infection.

Tank Care

Tank Setup Details
Water Temperature (22°C – 26°C)
Minimum Size 120 gallons
Water Hardness 5° to 15° dH
pH Level 6.6 – 7.5
Minimum population 1
Nitrate Content 0
Royal Pleco tank size and water level guide

Ideal Tank Size

Royal Plecos grow up to become giant fishes, so they require a lot of swimming space in the tank, at least 210 litres for one. Even though they seem to be not very active, a more prominent area means it’s less stressful for them when living with other fishes.

Also, if you decide to put two Royal Plecos together, make sure the tank is at least 200 gallons (757 litres) to curb a little stress between the two, especially if both are male.

Tank Setup

  • Plants
    There is no preference for what plants to use, but using plastic or artificial plants is not advised.
    They could accidentally rasp on leaves of the artificial plants mistaking them for real plants, which may prove to be hazardous for them.
  • Lighting
    Royal Plecos live in murky freshwaters, and their surrounding is mostly dark due to less light penetration. So, the use of dim or low lighting should be preferred so their natural surroundings simulated without impacting the water quality of your tank.
  • Substrate
    For substrate, you should use sand or big gravel and pebbles to give the likeness of river basins.
    Be careful not to use small gravels that would fit in their mouth because they are bottom dwellers, and their suction-like mouth can accidentally suck in small gravels.
  • Filtration and Other Apparatus
    To keep the tanks clean, you need good filtration as they are big fish and a full-grown Royal Pleco tends to eat and excrete a lot. It also raises nitrogen levels in the tank.
    One to two small filters or one oversized filter should be enough for a 120 Gallon tank. The filters should be able to produce current in the tank.
  • Decorations
    Avoid using the decorative colored stone chips as they are small enough to fit in their mouth and some are even sharp which may hurt the fish. Putting designer wood logs choice, as they give a natural look and are a source of food for them too.
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Water Parameters

Royal Plecos are hardy fish, they live in murky waters, but they require suitable water conditions to grow and thrive.

Water temperature should be between 71°F – 79°F, which is approximately close to the temperature in their habitat.

The Tank pH should be between 6.6 – 7.5 but ideally should be close to neutral. If the pH of the water becomes too acidic or alkaline, you can add salts to balance it out. The water hardness should be 5° to 15° dH range.

The water should be changed and replenished on a bi-weekly basis of about 25-30 percent of the total volume.

Compatibility With Other Fishes

Royal Plecos do quite well with other fishes except their own and maybe some species of catfish. So before putting two different plecos or a catfish together, ask an expert or do some research online.

Try not to put them with fishes who are also bottom dwellers. It raises competition and tension among the fishes.

It is preferred to put fishes that are of similar size and non-attackers. Smaller ones are only recommended if they are put in schools.

A few species that are compatible with them are-

  • Silver Dollars
  • Oscars
  • Zebrafish
  • Cichlids
  • Headstands
  • Rummy Nose Tetra
  • Black Skirt Tetra


Are Royal Plecos Nocturnal?

Yes, Royal Plecos are nocturnal. They seem to be most active at night. During the day, you will see them idle most of the time.

My Royal Pleco is sleeping upside down, is it normal?

Yes, sometimes they may fall asleep while sticking to a piece of wood or decoration upside down. And during that time, they can sometimes fall into that position without waking up. It may seem unnatural but it’s a perfectly normal phenomenon for them.

Can Royal plecos live with Betta fish?

Yes, they can be kept with them. Bettas are naturally aggressive but they don’t bother plecos. And given the size and nature of Royal plecos, living at the bottom of the tank, they can peacefully live with Bettas.

How do we know if our Royal Pleco is getting sufficient food?

While putting food in the tank, if the fish hurries to eat it, that means it was quite hungry. If the food gets ignored then it is obviously full. So feed it a few times in a day but in small quantities so the food isn’t wasted. Excess leftover food particles may increase the nitrogen levels in the tank.

Are Royal Plecos rare?

Yes, they are considered a rare find in the market because they are difficult to breed in aquariums. So, they are primarily caught in the wild and then sold in the market.

Final Thoughts: Should We Get Them Home?

Yes, they are considered good ornamental fishes for aquariums and a rare find. With a well-scaped aquarium simulating a riverbed, they will do quite well.

There is no hassle with food, as a log of driftwood will be sufficient to keep them fed for weeks. And there is no extra need for any other decorations.

So, if you are looking for a designer catfish that would increase the natural aesthetic beauty of your tank, Royal Plecos are worth a go.

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About the Author

Shelby Crosby

Shelby is a passionate fishkeeper who has been writing about fish for over 5 years. She is a pro aquarist and holds a BSc Honors Degree in Wildlife and Fisheries. She creates her own beautiful aquarium layouts and loves to share her knowledge of tropical fish with other hobbyists. Career Highlights: Has worked with several…

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