Pterygoplichthys multiradiatus (Orinoco Sailfin Catfish)

Last updated on September 8th, 2022 at 02:53 am

Pterygoplichthys multiradiatus, also known as the Orinoco sailfin catfish, is one of the largest species of freshwater fish in South America, and it’s widely spread throughout rivers in Colombia, Brazil, Ecuador, Peru, and Venezuela. This species can weigh up to 25 kilograms (55 pounds) and be more than 2 meters (6 feet) long, but they’re not typically aggressive or dangerous to humans unless provoked or disturbed during the breeding season.

Pterygoplichthys multiradiatus (informally Orinoco sailfin catfish) are freshwater fish belonging to the Pterygoplichthys genus in the Loricariidae family of the order Siluriformes. They are called sailfin catfish due to their large dorsal fins, which have been known to reach lengths of up to 7 inches (18 cm). They inhabit most major rivers in tropical South America and can be found from southern Colombia down to northern Argentina.

The Orinoco sailfin catfish (Pterygoplichthys multiradiatus) lives in the Orinoco river basin of Venezuela and Colombia, as well as coastal rivers in Guyana and Suriname. It has no scales, and the base of its caudal fin extends into an elongated filament that can be twice as long as the body, resembling a sail or rudder, giving the fish its common name. It occasionally makes its way into the aquarium trade. It grows to about 20 cm (8 in) SL, but usually only half that size in aquaria.

Origin and descriptions

Pterygoplichthys Multiradiatus

The pterygoplichthys multiradiatus is a species of catfish in Loricariidae family. It was described by Ernest E. Williams in 1949, originally under the genus Pterygoplichthys. It inhabits large rivers in northern South America, Guyana, and Suriname and can be found over mud or sand bottoms. Its diet consists mostly of insects and detritus. It grows to a length of 28 inches (70 cm).

The fish has two dorsal fins with long filamentous extensions containing numerous filaments; its anal fin extends past its tail, and it has 7-8 anal fin rays that are similar to those on its dorsal fin. This fish’s back is dark brown fading into lighter brown towards its belly. The upper parts have numerous irregular dark spots with areas between them being a dull yellowish-white coloration.

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Species profile

Pterygoplichthys Multiradiatus

Pterygoplichthys multiradiatus is an elongated freshwater catfish that grows to a length of around 70 cm and lives in South America. The Orinoco sailfin catfish is found in tropical freshwaters including rivers and lakes with dense vegetation.

Its diet consists mostly of insects and crustaceans but larger specimens are thought to also feed on frogs, birds, snakes, lizards, and other small mammals that fall into their habitat. These predators do not appear shy or scared when confronted by humans which may be due to their large size making them feel less threatened by potential attackers.


The Orinoco sailfin catfish is commonly found in rivers, streams, and lakes throughout much of South America. It spends most of its time near or within aquatic vegetation or rooted grasses. Water levels should remain stable year-round.

Pterygoplichthys multiradiatus size

These species can grow up to 28 inches (70 cm) in length.

Pterygoplichthys multiradiatus tank size

The minimum recommended tank size is 455 Liters (100 gallons)

Tank set up

The fish need a large aquarium with plenty of hiding places. They will devour live plants, so be sure to only add plastic or silk ones, and your fish will love them just as much. Orinoco sailfin catfish are schooling fish that need to be kept in groups of six or more for optimum health. If you see one fish swimming on its own, that could mean there is something wrong with it, so isolate it until you’re sure it’s healthy.

Because these fish can grow quite large, they need tanks larger than 60 gallons. A 100-gallon tank at minimum should be used if they are being housed alone. When adding new animals to an established tank, keep a close eye on any territorial squabbles, as they can get ugly quickly! Your best bet is to introduce new animals slowly over time.

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Be careful not to overstock tanks because Orinoco sailfin catfish do not tolerate water quality issues well and stress often leads to disease and illness.

Pterygoplichthys multiradiatus tank mates

The Orinoco sailfin catfish is a peaceful species that spends most of its time in open water. It does best in larger aquariums with plenty of swimming rooms and a variety of plants for it to hide among. The sailfin catfish’s large size and aggressive feeding habits, however, require it to be kept alone or in very large aquariums.

A fish only suited for advanced aquarists with a specific niche: larger tanks with lots of vegetation to provide cover and places to hunt invertebrates.

Some good tank mates are Asian Arowana, Redtail shark, Green Moray Eel, American Lobster, and Large Pleco. If you do decide to keep more than one Pterygoplichthys multiradiatus in your aquarium, you will have to be prepared for them to fight amongst themselves as they become adults. Also, make sure that each has enough room to do their own thing.

Pterygoplichthys multiradiatus breeding

Pterygoplichthys Multiradiatus

Multiradiatus is a substrate spawner, meaning that spawning occurs when two fish meet in an appropriate breeding area, such as a large plant leaf or an object such as driftwood. When both are ready to spawn, they perform small ritualized movements towards each other, swim together, and then embrace while releasing eggs and sperm simultaneously.

The pair will usually repeat these steps several times until all of their gametes have been released. Spawning typically takes place at dusk. Females can produce anywhere from 800-3200 eggs per brood and can lay 5-8 broods per year. Brood size ranges from 500-900 eggs with an average hatching rate of 85%.

This species has been known to breed in captivity but often spawns less frequently than some relatives because it has higher food requirements resulting from its more rapid growth rate and larger adult size. It may take up to 1 year for larvae to reach maturity depending on water conditions.

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There are reports that suggest wild-caught specimens require longer maturation periods which could be linked to stress caused by being removed from their natural habitat. Other reports suggest some wild-caught adults never mature and spend their entire lives in larval form.

Are Orinoco sailfin catfish aggressive or peaceful?

The Orinoco sailfin catfish is a large peaceful freshwater fish and will not bother other species. However, they will defend their territory against members of their own species. To avoid aggression with multiple individuals it is best to keep only one per tank or at least have a large enough tank so there are plenty of hiding places for each individual to have their own space.

Pterygoplichthys multiradiatus care

Pterygoplichthys Multiradiatus

The Orinoco sailfin catfish requires a diet of pellets, frozen bloodworms, and brine shrimp. When caring for a freshwater aquarium, keep in mind that you must closely monitor water temperature and regularly perform partial water changes to prevent ammonia buildup from fish waste.

Pterygoplichthys Multiradiatus generally does not require complex filtration systems; however, regular filter maintenance is key for healthy water conditions. Aquascaping also plays an important role in maintaining your freshwater tank. Plants should be used to help improve oxygen circulation throughout your aquarium while creating a natural habitat for fish and invertebrates.

Though considered difficult to spawn in captivity, female Orinoco sailfin catfish can lay as many as 7500 eggs at once!

Pterygoplichthys Multiradiatus diet

This is an omnivorous catfish, but it mainly feeds on zooplankton. Other food items include insect larvae, worms, small fish, and crustaceans. It does not eat very much plant material; instead, most of its diet comes from animal prey. At times, larger fish will feed on juvenile Pterygoplichthys multiradiatus. However, these predators are more likely to take advantage of juveniles that have been injured by other predators or eaten by other large animals.

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Water parameters

Pterygoplichthys MultiradiatusIdeal water must have a pH 6.0-7.5, Temperature 26-30 degrees C (80-86 degrees F), Water hardness <10 dGH (3–6 °dH), Specific gravity 1.005 – 1.015 , Ammonia (NH3/NH4+): 0, Nitrite (NO2-): 0, and Nitrate (NO3-) 10 – 40 ppm. No more than two fish species from a similar range should be kept in a single aquarium; for Orinoco sailfin catfish at least one can keep with other corydoras and loricariids.

Pterygoplichthys Multiradiatus lifespan

In captivity, they can live up to 15 years with good care.

Parasites and diseases

Ornamented catfishes of genus Pterygoplichthys, such as Pterygoplichthys multiradiatus, have a remarkable number of parasites and diseases caused by them. The parasite guild on these fish is very complex, containing mostly digeneans and monogeneans but also including myxosporidians.


The Orinoco sailfin catfish is a small, popular aquarium fish with large fins and a long dorsal fin. These features make it easy for predators to spot and catch them during feeding time. However, Pterygoplichthys multiradiatus’s characteristic silver color makes it nearly invisible when swimming in murky water or when they stay still.

Some common predators are pacu, snappers, and barbs. Larger members of Pterygoplichthys species will eat them as well.

Do Pterygoplichthys Multiradiatus make good pets?

In short, no. Pterygoplichthys Multiradiatus require way too much-specialized care for a casual hobbyist to be successful with them as a pet. They need to be kept in tanks of 1,000 gallons or more, which is more than some residential properties are allowed. As these fish grow older and larger they become too large to be housed in an aquarium, making them impossible as pets in most cases.