Not furry, but we like them anyway.
Hoplo Catfish
Megalechis thoracata (Valenciennes, 1840)
Also called Spotted hoplo, Black marble hoplo, Hoplosternum thoracatum (former name)
From Widespread in northern South America east of the Andes: the Amazon, Orinoco and upper Paraguay basins plus coastal rivers of the Guianas and northern Brazil, mainly in still waters.123
At a glance the quick version
Looks how to spot one
Armoured catfish (bony plates, no scales)
A sturdy armoured catfish clad in bony plates instead of scales, with sensitive barbels at the mouth. It is patterned with dark spots, which earns it the name spotted hoplo. In breeding condition males show a thickened orange-yellow first pectoral ray and a more colourful belly.3
Personality what they are like
Calm and tolerant, it fits with small tetras and barbs as well as larger, boisterous fish. The only time it gets feisty is when a male is guarding his bubble nest.32
Daily activity how busy a day looks
A bottom forager that also makes regular trips to the surface for air; it needs a roomy floor area and some cover.32
Grooming and care the hands-on bits
A soft sand bottom protects its barbels, and hiding places help it settle. Keep water mature and well filtered with routine partial changes.2
Home where they are happiest
Seriously Fish suggests a tank base of at least 120 x 38 cm (about 137 litres), 18 to 28 C, pH 6.0 to 8.0 and 0 to 20 dGH; Wikipedia advises at least 55 US gallons at 24 to 28 C.32
Food basics what goes in the bowl
Takes standard sinking aquarium foods readily, ideally with live or frozen extras; in the wild it eats small organisms and detritus.32
Company who they like around
Semi-social; Wikipedia suggests a group of five or more, and it mixes well with most community fish.23
The story where it all began
Achille Valenciennes described the spotted hoplo in 1840. Long sold as Hoplosternum thoracatum, it now sits in the genus Megalechis, and it is also eaten as a food fish in parts of South America.13
Fun facts for the dinner table
- 1
It breathes air through its gut: it swallows a gulp at the surface and absorbs the oxygen through the lining of its stomach and intestine.2
- 2
Males build floating bubble nests, often anchored under plants, and the eggs hatch in about 48 hours.3
- 3
Males make sounds during territorial displays and spawning.2
- 4
FishBase classes it as an obligate air-breather.1
Recognised by the official bits
- IUCN Red List
- Least Concern (assessed 20 October 2020)1
- Taxonomy
- Described by Valenciennes in 1840; formerly placed in Hoplosternum3
- Family
- Callichthyidae (armoured catfishes)3
The care rhythm a typical week and year
A typical home-care rhythm for a Hoplo Catfish. A starting point, not a vet's advice.
- FeedingSmall amounts once or twice a dayevery day
- Temperature checkevery day
- Water changeAbout 25% of the waterevery week
- Water testevery week
- Glass cleanevery week
- Filter rinseRinse in old tank water, never tap waterevery month
Owner questions the things everyone asks
How often should I feed my Hoplo Catfish?
Feed your Hoplo Catfish small amounts once or twice daily using sinking pellets or tablets. Live or frozen treats like bloodworms make great extras. Adjust portions based on the food label and your fish's appetite.32 Pet Wiki plan
What does a Hoplo Catfish eat, and what should it never eat?
It eats sinking aquarium foods and enjoys live or frozen treats such as bloodworms and brine shrimp. Our sources don't list specific forbidden foods, so ask a vet or good breeder for advice on what to avoid.32
How much space does a Hoplo Catfish need?
A tank of at least 55 US gallons (about 208 litres) with a base of 120 x 38 cm gives this bottom-dweller plenty of room. A spacious floor area with hiding spots is ideal.32
What temperature, light or water does a Hoplo Catfish need?
Keep water temperature between 18-28°C (24-28°C is ideal), pH 6.0-8.0, and hardness 0-20 dGH. Provide moderate lighting and some cover like plants or caves.32
How often should I clean a Hoplo Catfish's home?
Change about 25% of the water weekly, test water weekly, and clean the glass. Rinse the filter monthly in old tank water to keep the environment healthy. Pet Wiki plan
Can a Hoplo Catfish live with others?
Yes, it's a peaceful community fish that gets along with small tetras, barbs, and larger boisterous fish. For best social behavior, keep a group of five or more.32
How long does a Hoplo Catfish live?
Lifespan information isn't provided in our sources. For typical longevity, consult a vet or experienced breeder.
Can I handle a Hoplo Catfish?
Handling is not recommended as it can stress the fish and damage its sensitive barbels. Enjoy watching it forage on the bottom and take trips to the surface for air.3
Written from the sources on this page, a few checked guides (VCA, ASPCA, RSPCA) and Pet Wiki's own starting care plan. A friendly guide, not a vet's advice.
Where this comes from
Every fact on this page has a numbered source. Spotted an error? [email protected].
- FishBase: Megalechis thoracata fishbase.seused for distribution, size, weight, IUCN, air breathing
- Wikipedia: Megalechis thoracata en.wikipedia.orgused for common names, gut breathing, bubble nest, aquarium notes
- Seriously Fish: Megalechis thoracata seriouslyfish.comused for size, care, temperament, dimorphism, breeding, history
Checked 2026-09-30. Text is written in our own words from these sources.