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FishmediumFreshwater

Hoplo Catfish

Megalechis thoracata

📍 South America

The Hoplo Catfish is a large, armored South American catfish known for its ability to breathe air using a labyrinth organ, making it adaptable to various water conditions. These nocturnal bottom-dwellers are hardy and relatively easy to care for, though they require substantial tank space and can be aggressive toward smaller fish. They are popular among experienced aquarists seeking a unique, long-lived addition to their aquariums.

Size8"
Min Tank75g
semi-aggressive
Zonebottom

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Care Guide

Diet

Hoplo Catfish are omnivorous bottom feeders that accept high-quality sinking pellets, frozen bloodworms, and brine shrimp. Feed 2-3 times weekly, offering only what they can consume in a few minutes. They will also scavenge for leftover food and plant matter on the tank bottom.

Behavior

These nocturnal catfish are primarily active during evening and night hours, spending daytime hidden in caves or dense vegetation. They are solitary and territorial, often aggressive toward smaller fish and other bottom-dwellers. Hoplos can gulp air at the water surface, a normal behavior that should not be mistaken for distress.

Breeding

Breeding Hoplo Catfish in captivity is extremely difficult and rarely documented in home aquariums. They require very large tanks, specific water conditions, and careful pair selection. Professional breeders occasionally succeed, but most aquarium specimens are wild-caught.

Common Diseases

Ich (Ichthyophthirius multifiliis)

Symptoms

White spots on body and fins, rapid breathing, rubbing against surfaces

Treatment

Raise temperature to 28-30 C (82-86 F), perform water changes, use ich medication; Hoplos tolerate treatment well due to air-breathing ability

Bacterial Infection

Symptoms

Torn fins, sores on body, cloudy eyes, lethargy

Treatment

Improve water quality, perform 25-30% water changes, use broad-spectrum antibiotic medication if severe

Fin Rot

Symptoms

Frayed or deteriorating fins, discoloration at fin edges

Treatment

Maintain pristine water conditions with frequent water changes, use antifungal/antibacterial treatments, ensure adequate tank space to reduce stress

Parasitic Infections

Symptoms

Excessive scratching, visible parasites, weight loss, lethargy

Treatment

Use antiparasitic medication, quarantine affected fish, improve water quality and perform frequent water changes

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Quick Facts

diet
Omnivore - feeds on sinking pellets, frozen foods (bloodworms, brine shrimp), and occasional live prey
lifespan
10-15 years
max size
20 cm (8 in)
tank size
75 gallons minimum
temperament
semi-aggressive

Water it likes

ph
6.0-7.5
ammonia
0 ppm
nitrate
<20 ppm
hardness
5-15 dGH
temperature
72–82°F (22–28°C)

Stats

Community tips0
Kept by0 hobbyists