Royal Pleco (Panaque nigrolineatus): Ultimate Care Guide

A striking addition for larger aquariums, the Royal Pleco is a pleco species native to South America. Royal Plecos feature eye-catching striped patterns and tough skin plates instead of scales. One of the few species with an ability to digest wood, this fish needs to be provided with lots of driftwood with other foods such as prepared algae wafers. While this species resembles other plecos, they are bulkier and have large mouths with spoon-shaped rasping teeth ideal for scraping wood and rock.

Royal Plecos can be hardy with the right care. Let’s take a look at what you’ll need to know when adding this species to your aquarium!

Royal Pleco Care

Royal Plecos need larger aquariums with extensive filtration. A bottom-dwelling species, you’ll want to include lots of driftwood and rock for grazing. This large species will need additional foods such as prepared algae wafers and blanched vegetables.

Are Royal Pleco easy to care for?

The main challenge when caring for Royal Plecos is ensuring a large enough tank; at least 125 gallons is recommended. This species isn’t particularly susceptible to disease but needs to be protected from faster, fin-nipping tank mates.


Royal Plecos prefer water temperature between 72° – 79° F. Ideally keep temperatures on the warm side of this range. This species can become lethargic and have trouble feeding in colder water.

Water pH

Royal Plecos need mostly neutral water with a pH between 6.5 and 7.5. Keeping this range can be a challenge in tanks with large quantities of driftwood which can buffer acidity. If you find your pH is dropping too low, include a mesh bag with crushed coral or aragonite sand in your filter to increase water alkalinity.

Royal Pleco (Panaque nigrolineatus)
Royal Pleco (Panaque nigrolineatus)

Royal Pleco Size

Royal Plecos can grow up to 17 inches long in captivity. While this is a slow-growing fish, you’ll want to provide a large enough aquarium to ensure it will be comfortable when fully mature.

Growth Rate

Royal Plecos will take around 2 years to reach their mature size of 17 inches.

Food & Diet

While Royal Plecos will rasp and graze driftwood and rock, this is unlikely to provide enough nutrition in most aquariums. Regular foods should include prepared algae-based wafers and flake with small amounts of meatier foods in pellet, flake, or wafer forms. While Royal Plecos are herbivores, they can benefit from the occasional feeding of high-protein foods. This is a bottom feeding fish, so make sure any foods sink quickly. Specialty food products are available such as Repashy Morning Wood.

Royal Pleco Lifespan

Royal Plecos will live around 10 years in most aquariums. This species can live longer in larger tanks with expert care.

Royal Pleco Tank Size

Royal Plecos are a large species and need a minimum take size of 125 gallons. Ensure enough depth and width to allow this bottom-dwelling fish to comfortably move and turn as it grows larger. Rectangular tanks should have at least 18 inches of depth, but preferably 24 inches.

Tank Setup

Royal Plecos need large tanks with enough width and depth to allow easy movement. Provide lots of driftwood and rocks for grazing and excellent filtration. This fish keeps to the bottom areas of aquariums and isn’t a powerful swimmer. Their tanks should have enough floor area to allow easy movement. You’ll want to plan for their large mature size.

Plenty of driftwood is critical as Royal Plecos are constant grazers. They don’t only scrape wood and rock for algae but can rasp away at, and eat, wood. Their grazing behavior can destroy many common aquarium plants. Any attempt at a planted tank with this species needs to be approached carefully. Floating plants like duckweed are usually safe bets but large leafy plants are tempting targets for this species. Plastic plants aren’t a good choice as Royal Plecos will rasp at these and ingest plastic particles which can cause digestive problems and might kill your fish.

Filtration will be another important consideration. This is a messy fish, particularly as it grows in size. You’ll need a powerful filtration system which will likely include canister filters and power heads. Using power heads to create tank currents is important to kick up debris and allow for removal by the filtration system. Without enough flow inside the aquarium, debris can collect–especially under driftwood–and rot, causing water quality to suffer. When placing power heads, make sure to avoid creating dead spots of inadequate current.

Royal Pleco Breeding

Royal Plecos a difficult to breed in captivity. To even attempt this you’ll need a bonded pair. This fish will attack others of the same species so you can’t just add any male and female to the same tank. In nature, Royal Plecos mate during the rainy season. To simulate this you’ll need to gradually increase acidity, soften the water and lower tank temperatures slightly. Feed with high quality food to encourage breeding. Vine wood is a popular choice as it is soft and easy to digest. If mating is successful the female will lay eggs in debris piles at the bottom of the tank.

Royal Pleco Male or Female

Royal Plecos are difficult to sex correctly. Some hobbyists report that mature males have more pointed anal vents. Sex differences in other pleco species are more obvious, but methods that work with these fish don’t apply to Royal Plecos.

Royal Pleco Disease

Royal Plecos are somewhat disease resistant but can still succumb to common freshwater fish maladies such as Ich, Dropsy and Tail Rot. Treating this species can be complicated because some common medications, such as those with a copper base, cannot be used. An example of this is Ich. Ich is a common freshwater fish disease that appears as tiny white spots on body, gills, fins and tail. This condition is commonly treated with copper-based medications but these aren’t tolerated by Royal Plecos. The usual solution is to increase tank water temperature to 86° F until the Ich bacteria life cycle is disrupted and it dies off. Not all fish can tolerate higher temperatures so this method can involve moving your Royal to a quarantine tank (QT) for treatment.

Different diseases have different treatment methods and possible medications. Make sure that whatever treatment path you take will be tolerated by your Royal Pleco.

Royal Pleco Tank Mates

A great addition to a community tank, Royal Plecos can get along with many other fish species. Exceptions include other Royal Plecos and catfish species. This is a bottom-dwelling fish so will stay clear of fish that swim in middle and upper parts of the water column.

Are Royal Pleco Aggressive?

Royal Plecos are aggressive to fish of the same species and many catfish varieties. You should only keep one Royal Pleco per tank to avoid serious problems. Catfish, which this species views as competition for food, can also be subject to aggressive behavior.

Examples of Compatible and Incompatible Tank Mates

The list of good tank mates for Royal Plecos is long: Flag and Jaguar Cichlids are good choices along with Tetras such as the Congo and Rummy Nose. It is important to avoid having more than one Royal Pleco per tank. Also, most catfish varieties would be bad tank mates as Royals don’t like competition for food.

Where can I find Royal Pleco for sale?

Royal Plecos are sometimes available in fish stores but often you’ll need to buy from Internet sources. Online purchases are often needed for uncommon types.

Royal Pleco Price

Royal Pleco pricing is dependent on type and size. A small L190 type of about 1 ¾ to 2 inches can be bought for around $20 USD. A large specimen of the same type, about 14 inches, can go for about $270 USD.

Royal Pleco Types

Royal Plecos come in various types identified by an “L” followed by a number. The most common type of Royal Pleco is an L190 but many others are available. Let’s take a look a some of the choices that are possible.

Watermelon Royal Pleco

Watermelon Royal Pleco (L330) is a larger type of Royal Pleco that can grow to 20 inches in length. Also called the Spotted Royal Pleco, this type features a distinctive spotted pattern and often red eyes.

Blue Eyed Pleco

Blue Eyed Pleco is a rare and expensive variety with a dark gray to black body and turquoise eyes. Often out of stock, this can be an extremely difficult variety to find for sale.

Broken Line Royal Pleco

Broken Line Royal Pleco (L191), also called Dull-Eye Royal Pleco, features jagged and irregular lines on their body. This variety likes moderate to fast current flow.

Green Royal Pleco

Green Royal Pleco (L418)–also known as Peru Green Royal Pleco–is native to fast, white water regions of the Amazon in Peru and Ecuador. Featuring olive to green body coloration with well-defined striping patterns, this is a particularly eye-catching variety.

Platinum Royal Pleco

Platinum Royal Pleco (L027a), also known as the Long Nose Royal Pleco, have longer bodies than

many other Royal Plecos and a base coloration of whitish silver.

Gold Line Royal Pleco

Gold Line Royal Pleco (L027c), also known as Thunder Line, features a greenish-gold base color. This coloration ranges from slightly yellow-tinted green to a striking yellow with green tint.