🦄 Unicorn Catfish – (Ageneiosus magoi) – Wild-Caught Orinoco Driftwood Catfish

The Unicorn Catfish (Ageneiosus magoi) is a highly distinctive South American driftwood catfish with a sleek, streamlined body, unusually small barbels, bold dark lateral markings, and fascinating breeding-season changes in mature males.

Unlike many catfish that spend most of their lives resting on the bottom, Ageneiosus magoi is an active:

OPEN-WATER / PELAGIC CATFISH

that requires substantial swimming room.

The species is native to the:

RIO ORINOCO BASIN OF VENEZUELA

including the Orinoco, Apure, Portuguesa, Guárico, and associated floodplain and river systems.

It is also an opportunistic predator capable of swallowing smaller aquarium fish.

However, it is better described as:

PREDATORY RATHER THAN GENERALLY AGGRESSIVE

and can coexist with appropriately sized tankmates that are too large to swallow.

This listing is for:

WILD-CAUGHT UNICORN CATFISH

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🔎 Quick Facts – Unicorn Catfish

• 📛 Common Name: Unicorn Catfish
• 📛 Other Names: Dolphin Catfish, Slopehead Catfish
• 🔬 Scientific Name: Ageneiosus magoi
• 📅 Formally Described: 1989
• 🐟 Family: Auchenipteridae
• 🧬 Subfamily: Auchenipterinae
• 🌿 Stock: Wild Caught
• 📏 Current Size: Approximately 4–5 inches
• 🇻🇪 Country: Venezuela
• 🌊 Native Drainage: Rio Orinoco Basin
• 📍 Type Locality: Esteros de Camaguán, Guárico, Venezuela
• 💧 Water Type: Freshwater
• 🐟 Lifestyle: Pelagic / Active Open-Water Catfish
• 📏 Documented Scientific Specimens: At least 20.5 cm / 8.1 inches standard length
• 📏 Adult Planning Size: Approximately 8–10 inches total length
• 🏠 Recommended Aquarium: Approximately 125 gallons or larger
• 📐 Aquarium Length: Approximately 5–6 feet or longer strongly preferred
• 🌡️ Temperature: Approximately 75–83°F
• 💧 pH: Approximately 6.5–7.5
• 💦 Water: Soft to moderately mineralized
• 💨 Oxygenation: Good to High
• 🌊 Water Movement: Moderate
• 🏊 Swimming Space: Very Important
• 🍽️ Diet: Predatory Carnivore
• 🦐 Primary Foods: Fish, crustaceans, insects, worms, and other animal foods
• 🚫 Feeder Fish Required: No
• 😌 Temperament: Generally peaceful toward fish too large to swallow
• ⚠️ Predatory: Yes
• 🐟 Small Fish Safe: No
• 👥 Conspecifics: Can be kept with similarly sized individuals when adequate space is provided
• 🌙 Activity: Crepuscular / nocturnal but often active during daylight
• ♂️ Breeding Male: Develops enlarged curved dorsal spine, longer barbels, and modified anal fin
• 🥚 Aquarium Breeding: Not reliably documented
• ⭐ Care Level: Intermediate to Advanced
• 🌎 IUCN Status: Least Concern

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🧬 Valid Scientific Species

The currently accepted scientific name is:

Ageneiosus magoi

The species was formally described in:

1989

by Castillo and Brull.

A major taxonomic revision of the genus Ageneiosus in 2017 continued to recognize:

Ageneiosus magoi

as a valid species.

Therefore, the correct product identification is:

Unicorn Catfish – (Ageneiosus magoi)

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🦄 Important “Unicorn” Correction

The older product description states that this fish has a:

“horn-like extension on its snout.”

That should be removed.

THE UNICORN CATFISH DOES NOT HAVE A PERMANENT HORN ON ITS SNOUT.

Instead, one of the most remarkable features of this species occurs in:

SEXUALLY ACTIVE MALES

during the reproductive season.

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♂️ The Male's Temporary “Horn”

When a mature male enters breeding condition, the:

FIRST DORSAL-FIN SPINE

becomes dramatically:

• Enlarged
• Elongated
• Curved
• Irregularly shaped

This structure can give a mature breeding male an unusual horn-like appearance.

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🔄 The Dorsal Spine Changes Again After Breeding

Even more unusual:

THE ENLARGED BREEDING SPINE IS TEMPORARY

After the reproductive period, the exaggerated dorsal structure regresses.

The male can then become considerably harder to distinguish from a female.

This unusual seasonal transformation is one of the most fascinating characteristics of Ageneiosus catfish.

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🧔 Almost “Beardless”

The genus name:

Ageneiosus

comes from Greek roots referring roughly to:

WITHOUT A BEARD

This refers to the extremely reduced barbels compared with the prominent whiskers found on many other catfish.

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🔬 Tiny Maxillary Barbels

Under normal conditions, the maxillary barbels are:

• Extremely small
• Easily overlooked
• Partly concealed near the upper lip

This gives the fish a very different facial appearance from typical long-whiskered catfish.

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♂️ Male Barbels Change During Breeding

During reproductive condition, mature males can develop:

ELONGATED MAXILLARY BARBELS

These temporary structures are associated with mating behavior.

After the reproductive period, they regress again.

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🎨 Appearance

The Unicorn Catfish has an elongated, hydrodynamic body designed for active swimming.

Typical coloration includes:

• Silver
• Gray
• Cream
• Pale bronze
• Yellowish tones

combined with:

• Dark brown
• Charcoal
• Black

markings.

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➖ Lateral Stripes

Many specimens display two prominent dark markings extending along the sides of the body.

These may appear as:

• Continuous dark stripes
• Broken stripes
• Irregular bands
• Rows of blotches

depending on the individual.

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⚫ Spotted & Marbled Markings

Additional dark markings can appear across the:

• Head
• Flanks
• Dorsal fin
• Caudal fin

creating an attractive mixture of:

• Spots
• Blotches
• Stripes
• Marbling

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🟡 Yellow Coloration

Some wild specimens display an attractive:

YELLOW OR GOLDEN TINGE

to portions of the body and fins.

However, this coloration may:

• Fade after import
• Change with maturity
• Vary between specimens
• Appear differently under aquarium lighting

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⚠️ Color Disclaimer

Exact coloration cannot be guaranteed.

Individual wild fish may differ in:

• Stripe width
• Spot size
• Number of blotches
• Yellow coloration
• Body darkness
• Fin pattern

Color may also change temporarily because of:

• Shipping
• Stress
• Lighting
• Aquarium background
• Diet
• Water quality
• Acclimation

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🌎 Native Distribution

Ageneiosus magoi is native to:

VENEZUELA

within the:

RIO ORINOCO BASIN

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📍 Type Locality

The original type locality is:

ESTEROS DE CAMAGUÁN

in:

GUÁRICO STATE, VENEZUELA

This area forms part of the broad Orinoco floodplain ecosystem.

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🌊 Documented River Systems

Scientific records include fish from areas associated with:

• Rio Orinoco
• Rio Apure
• Rio Portuguesa
• Rio Guárico
• Rio Caracol
• Rio El Canito
• Caño Dora
• Caño Maporal
• Caño Anabata
• Caño Araguaito
• Lago Tineo
• Esteros de Camaguán

This is a much more widespread Orinoco-basin species than a fish restricted to one tiny rocky locality.

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🌾 Floodplain Habitat

The type region includes extensive:

• Floodplains
• Seasonal wetlands
• River channels
• Lagoons
• Caños
• Flooded habitats

This is important because the Unicorn Catfish should not be described as strictly inhabiting:

FAST ROCKY RAPIDS

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🏊 Pelagic Catfish

FishBase classifies Ageneiosus magoi as:

PELAGIC

which is unusual for a catfish commonly placed in the aquarium's “bottom-fish” category.

The Unicorn Catfish spends considerable time:

ACTIVELY SWIMMING THROUGH OPEN WATER

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⚠️ Not a Typical Bottom-Dwelling Catfish

Do not expect this species to spend its entire life:

• Sitting inside a cave
• Attached to wood
• Resting on the substrate

It is much more active than many:

• Plecos
• Doradids
• Large benthic catfish

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🏠 Aquarium Size

Although the Unicorn Catfish does not reach the enormous size claimed on some older aquarium pages, it still deserves a:

LARGE AQUARIUM

because it is such an active swimmer.

For long-term housing:

APPROXIMATELY 125 GALLONS OR LARGER

is recommended.

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📐 Aquarium Length Is Extremely Important

For Ageneiosus magoi:

SWIMMING LENGTH MATTERS MORE THAN EXCESSIVE HEIGHT

A tank approximately:

5–6 FEET LONG OR LONGER

is strongly preferred.

This becomes especially important when keeping:

• Multiple Unicorn Catfish
• Large tankmates

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⚠️ Why Such a Large Aquarium for a 10-Inch Fish?

The recommendation is based on:

BEHAVIOR

not merely body length.

The Unicorn Catfish is:

• Streamlined
• Fast
• Pelagic
• Active
• Capable of rapid bursts of swimming

A short aquarium can severely restrict its natural behavior.

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📏 Adult Size – Important Correction

The older product page lists:

12–14 INCHES

as the maximum size.

That is considerably larger than the best-supported scientific information.

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🔬 Scientific Records

FishBase currently lists approximately:

18.1 CM / 7.1 INCHES STANDARD LENGTH

However, the comprehensive 2017 taxonomic revision examined Ageneiosus magoi specimens reaching:

205 MM / 20.5 CM STANDARD LENGTH

or approximately:

8.1 INCHES BEFORE THE TAIL

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📏 Specialist Aquarium Size

Long-established aquarium references report adults around:

24 CM

or approximately:

9.5 INCHES TOTAL LENGTH

Therefore, for responsible customer planning:

EXPECT APPROXIMATELY 8–10 INCHES TOTAL LENGTH

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⚠️ Remove the 12–14 Inch Claim

There is currently insufficient evidence to advertise:

12–14 INCHES

as the normal adult size for Ageneiosus magoi.

That larger size may result from confusion with:

OTHER AGENEIOSUS SPECIES

some of which grow substantially larger.

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🆚 Other Ageneiosus

The genus contains multiple species that can appear similar in the aquarium trade.

Some grow much larger than:

A. magoi

Accurate identification is therefore important.

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⚠️ Do Not Identify Solely by Common Name

Names such as:

• Dolphin Catfish
• Bottlenose Catfish
• Slopehead Catfish
• Unicorn Catfish

may be applied inconsistently within the trade.

Always preserve:

Ageneiosus magoi

as the scientific identification for this product.

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🪵 Driftwood

Driftwood can be included for:

• Shade
• Cover
• Visual structure
• Natural appearance

but do not overcrowd the aquarium with décor.

Remember:

THIS FISH NEEDS OPEN SWIMMING SPACE

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🪨 Aquarium Setup

A suitable aquarium should include:

• Large open swimming areas
• Smooth driftwood around the edges
• Robust plants around the perimeter if desired
• Smooth rocks
• Sand or smooth substrate
• Dimmer resting areas
• Strong filtration
• Good oxygenation

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🌿 Keep the Center Open

Place much of the décor around the:

• Back
• Corners
• Sides

while maintaining:

AN OPEN CENTRAL SWIMMING AREA

This allows the fish to display its natural movement.

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⚠️ Avoid Sharp Décor

Because this is a fast-moving fish, avoid sharp decorations that could cause injury during:

• Feeding
• Startle responses
• Nighttime swimming

Smooth aquarium furnishings are preferred.

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🌡️ Temperature

A practical maintenance range is:

75–83°F / APPROXIMATELY 24–28°C

The current 75–82°F recommendation is therefore already reasonable.

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💧 Water Parameters

A practical long-term range is:

• 🌡️ Temperature: Approximately 75–83°F
• 💧 pH: Approximately 6.5–7.5
• 💦 Hardness: Soft to Moderately Mineralized
• 💨 Oxygenation: Good to High
• 🌊 Water Movement: Moderate
• ☠️ Ammonia: 0 ppm
• ☠️ Nitrite: 0 ppm
• 🔄 Nitrate: Keep reasonably low

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🌊 Moderate Water Movement

The old page recommends:

MODERATE TO STRONG FLOW

I would soften that.

The species occurs across:

• River channels
• Floodplain habitats
• Lagoons
• Caños

and does not require a high-speed river-torrent aquarium.

Provide:

GOOD CIRCULATION + GOOD OXYGENATION

rather than excessive current.

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💨 Oxygenation

Maintain dependable oxygenation using:

• Surface agitation
• Air stones
• Strong filter returns
• Sump filtration
• Appropriate circulation

This is particularly important in warm water and heavily stocked aquariums.

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💩 Filtration

As a carnivorous catfish, A. magoi can produce significant organic waste.

Recommended filtration may include:

• Large canister filters
• Sump filtration
• Strong biological filtration
• Efficient mechanical filtration

Maintain:

AMMONIA = 0

and:

NITRITE = 0

at all times.

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🔄 Water Changes

Regular partial water changes are important.

The exact schedule depends on:

• Aquarium size
• Number of fish
• Feeding
• Filtration
• Nitrate production

Do not allow large quantities of uneaten protein foods to remain in the aquarium.

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🍽️ Diet – Predatory Carnivore

The Unicorn Catfish is primarily:

CARNIVOROUS

Natural diet studies have documented foods including:

• Fish
• Shrimp
• Aquatic insects
• Insect larvae
• Other arthropods
• Frogs seasonally

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🦐 Recommended Aquarium Foods

Suitable foods include:

• Shrimp
• Prawns
• Mysis shrimp
• Krill
• Mussel
• Earthworms
• Nightcrawlers
• Insect larvae
• Quality carnivore pellets
• Appropriate sinking or slow-sinking prepared foods

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🐟 Fish-Based Foods

Appropriate fish flesh can also be used as part of a varied diet.

Good choices include appropriately prepared:

• Tilapia
• Other safe fish flesh

Cut food into portions appropriate for the catfish's mouth.

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🚫 Live Feeder Fish Are Not Necessary

The old page recommends live or frozen fish.

Although A. magoi naturally eats fish:

LIVE FEEDER FISH ARE NOT REQUIRED

Feeder fish can introduce:

• Parasites
• Bacteria
• Disease
• Nutritional problems

A varied diet of safe frozen, fresh, and prepared foods is preferable.

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🌿 Small Amounts of Plant Material

Natural dietary studies have found small amounts of:

• Plant matter
• Detritus

in Ageneiosus magoi.

Captive fish have also been observed accepting some vegetables.

However:

THIS REMAINS A PREDOMINANTLY CARNIVOROUS SPECIES

Plant foods should be considered occasional dietary variety, not the foundation of the diet.

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⚠️ Do Not Overfeed

Predatory catfish can readily consume more food than necessary.

Overfeeding can lead to:

• Obesity
• Excess waste
• Poor water quality
• Fatty deposits

Feed appropriately sized portions and monitor body condition.

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🐟 Predatory – But Not Necessarily Aggressive

The older page describes the Unicorn Catfish as:

AN AGGRESSIVE PREDATOR

That wording can give customers the wrong impression.

A better description is:

PREDATORY BUT GENERALLY NOT COMBATIVE TOWARD SUITABLY SIZED FISH

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⚠️ The Mouth-Size Rule

Any fish small enough to fit into the Unicorn Catfish's mouth should be considered:

POTENTIAL FOOD

This includes:

• Small tetras
• Small barbs
• Small livebearers
• Small catfish
• Small cichlids

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🐠 Suitable Tankmates

Potential tankmates include appropriately sized:

• Silver dollars
• Larger characins
• Large peaceful cichlids
• Large loricariids
• Similar-sized catfish

provided they are:

• Too large to swallow
• Not excessively aggressive
• Compatible with the same water conditions

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⚠️ Slow Fish

Use judgment with slow-moving fish small enough to be swallowed.

The Unicorn Catfish has a:

LARGE PREDATORY MOUTH

relative to its streamlined body.

A tankmate does not need to be tiny to become potential prey.

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👥 Keeping Unicorn Catfish Together

Ageneiosus magoi can be maintained with:

SIMILARLY SIZED CONSPECIFICS

when adequate aquarium space is available.

They are not necessarily solitary fish.

However:

DO NOT CROWD THEM

Their active swimming behavior requires considerable room.

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🏊 Group Housing

A small group requires:

• A very large aquarium
• Long swimming space
• Strong filtration
• Multiple feeding locations

For several adults:

LARGER THAN 125 GALLONS IS STRONGLY PREFERRED

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🌙 Activity

Although often considered nocturnal, the Unicorn Catfish can be:

SURPRISINGLY ACTIVE DURING THE DAY

Specialist keepers have observed the species swimming openly during daylight.

Activity may increase:

• At dusk
• During feeding
• At night

but do not expect this fish to remain hidden constantly.

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🧪 Wild-Caught Acclimation

This listing is for:

WILD-CAUGHT UNICORN CATFISH

After arrival:

• Keep lighting subdued
• Provide open swimming space
• Provide some sheltered areas
• Maintain good oxygenation
• Avoid sudden temperature changes
• Avoid sudden pH changes
• Maintain excellent filtration
• Confirm feeding

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🍽️ Confirm Feeding

Wild fish may initially prefer:

• Shrimp
• Worms
• Insect foods
• Frozen animal foods

Once acclimated, many can learn to accept:

• Quality pellets
• Prepared carnivore foods

Transition gradually rather than allowing the fish to go without food for extended periods.

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♂️ Male vs. Female – One of the Most Fascinating Catfish Differences

Sexual dimorphism in Ageneiosus magoi is particularly unusual because mature males can transform dramatically during breeding condition.

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♂️ Breeding-Condition Male

A reproductively active male develops:

A LARGE, ELONGATED, CURVED FIRST DORSAL-FIN SPINE

along with:

ELONGATED MAXILLARY BARBELS

and a:

MODIFIED ANAL FIN

used as a reproductive organ.

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🧬 Modified Anal Fin

The first portions of the male's anal fin become thickened and modified into a:

COPULATORY ORGAN

sometimes described in scientific literature as a:

PSEUDOPENIS

This is associated with internal insemination.

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🤝 Specialized Mating Behavior

During mating, the male uses his modified:

• Dorsal spine
• Maxillary barbels
• Anal-fin reproductive structure

to help grasp and position himself with the female.

This is a remarkably specialized reproductive system among aquarium catfish.

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🔄 Male Features Regress

After the reproductive period:

THE MALE'S EXAGGERATED FEATURES REGRESS

The elongated dorsal spine and barbels diminish, and the reproductive structure becomes much less obvious.

As a result:

MALES AND FEMALES CAN BECOME DIFFICULT TO DISTINGUISH OUTSIDE BREEDING CONDITION

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🥚 Reproduction – Important Accuracy Note

The reproductive biology of Ageneiosus magoi is unusual but incompletely documented.

Mating involves:

INTERNAL INSEMINATION

through the male's modified anal fin.

However, detailed species-specific information regarding:

• Egg deposition
• Spawning season
• Egg number
• Incubation
• Larval development

remains limited.

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⚠️ Aquarium Breeding Is Not Established

There are currently:

NO RELIABLE, WELL-DOCUMENTED ROUTINE HOME-AQUARIUM BREEDING REPORTS

for Ageneiosus magoi.

Therefore:

DO NOT INVENT A CAVE-SPAWNING METHOD

This is not a pleco and does not reproduce using the typical male-guards-eggs-in-a-cave strategy seen in many Loricariids.

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🚫 Not a Cave Spawner

The Unicorn Catfish belongs to:

AUCHENIPTERIDAE

not:

LORICARIIDAE

Its reproductive biology is completely different from the plecos commonly sold alongside it.

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🌎 Conservation Status

Ageneiosus magoi is currently assessed as:

LEAST CONCERN

on the IUCN Red List.

The global assessment dates to:

2020

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🌎 Orinoco Endemic

Despite its Least Concern status, the species is geographically associated with the:

ORINOCO BASIN

rather than being widely distributed throughout all of South America.

Preserving accurate origin information remains important.

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⭐ Why Keep a Unicorn Catfish?

The Unicorn Catfish combines:

• 🦄 Extraordinary breeding-season male morphology
• 🏊 Active open-water swimming
• ➖ Beautiful striped and marbled patterning
• 🇻🇪 Venezuelan Orinoco origin
• 🐟 Unusual pelagic catfish behavior
• 🍽️ Predatory feeding behavior
• 🧬 Specialized internal reproductive anatomy
• 📏 Manageable approximately 8–10 inch adult size
• 👥 Ability to coexist with similarly sized individuals
• 🌎 Valid formally described scientific identity

into one of the most unusual South American catfish available to experienced aquarium keepers.

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⚠️ Important Considerations

Before purchasing a Unicorn Catfish:

• The correct scientific name is Ageneiosus magoi.
• The species was formally described in 1989.
• It remains a valid species after the modern revision of Ageneiosus.
• This listing is for wild-caught fish.
• The current specimens are approximately 4–5 inches.
• The species is native to the Rio Orinoco Basin of Venezuela.
• The type locality is Esteros de Camaguán in Guárico.
• Do not describe the fish as having a permanent horn on its snout.
• Sexually active males temporarily develop an enlarged curved dorsal-fin spine.
• Males also develop elongated barbels and a modified reproductive anal fin.
• These exaggerated male features regress after breeding condition.
• Scientific specimens have been examined to at least 20.5 cm standard length.
• Plan for approximately 8–10 inches total adult length.
• Remove the old 12–14 inch maximum.
• This is an active pelagic catfish.
• Provide substantial open swimming space.
• Approximately 125 gallons or larger is recommended.
• A 5–6 foot or longer aquarium is strongly preferred.
• Keep central swimming areas relatively open.
• Maintain approximately 75–83°F.
• Maintain pH around 6.5–7.5.
• Maintain good to high dissolved oxygen.
• Moderate circulation is sufficient.
• Do not describe it as requiring extreme river current.
• Feed a carnivorous diet.
• Shrimp, prawns, worms, insects, mussels, fish flesh, and quality carnivore foods are appropriate.
• Live feeder fish are unnecessary.
• Small fish will be eaten.
• The species is better described as predatory than inherently aggressive.
• Compatible tankmates must be too large to swallow.
• Similarly sized Unicorn Catfish can be kept together when sufficient space is available.
• Aquarium breeding is not reliably documented.
• Do not describe it as a cave spawner.
• The species is currently classified as Least Concern.
• Never release aquarium fish into natural waterways.

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🧬 Taxonomy

The currently accepted scientific name is:

Ageneiosus magoi Castillo & Brull G., 1989

Classification:

• Order: Siluriformes
• Family: Auchenipteridae
• Subfamily: Auchenipterinae
• Genus: Ageneiosus
• Species: magoi

Native range:

RIO ORINOCO BASIN – VENEZUELA

For this product, use:

Unicorn Catfish – (Ageneiosus magoi)

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📛 Common-Name Disclaimer

The aquarium name:

UNICORN CATFISH

should not be interpreted as meaning this fish possesses a permanent horn growing from its snout.

The most dramatic horn-like structure occurs in:

SEXUALLY ACTIVE MALES

when the first dorsal-fin spine becomes enlarged and curved.

Other common names for Ageneiosus species include:

• Dolphin Catfish
• Slopehead Catfish
• Bottlenose Catfish

Common names can be inconsistent, so:

THE SCIENTIFIC NAME SHOULD ALWAYS BE PRESERVED

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🚚 Live Fish Shipping

Live fish are professionally packed for safe transport.

Shipping availability depends on:

• Fish size
• Destination
• Weather conditions
• Carrier availability
• Applicable state and local regulations

Larger Unicorn Catfish may require:

• Larger insulated boxes
• Additional water
• Heavy-duty shipping bags
• Specialized packing

Please review our Shipping & Payment Information and Live Arrival Guarantee / DOA Policy before ordering.

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⚠️ Buyer Responsibility

Customers are responsible for confirming that Ageneiosus magoi may legally be purchased, possessed, transported, and received in their state or local jurisdiction before ordering.

Never release aquarium fish into natural waterways.