Marble Hoplo Catfish
Marble Hoplo Catfish (Megalechis thoracata) is a robust, hardy, and entertaining South American armored catfish with a bold marbled pattern of dark spots and blotches on a pale body. Related to Corydoras but belonging to a different family, the Hoplo is considerably larger and more boisterous — a fish with genuine presence and personality. It is an extraordinary air-breather that regularly visits the surface to gulp atmospheric air using a modified intestinal breathing system.
Feeding & Care Tip: Hikari Sinking Wafers and Hikari Mini Algae Wafers make excellent staples. Supplement with Hikari Frozen or Freeze-Dried Bloodworms and Hikari Frozen or Freeze-Dried Brine Shrimp 2–3 times per week. Ensure there is sufficient surface access — this fish must be able to reach the surface to breathe air and will stress if surface access is blocked.
Native to a vast range across South America and Trinidad — rivers, streams, ponds, and even seasonal pools that can become hypoxic during the dry season. The ability to breathe atmospheric air is an adaptation for surviving in low-oxygen conditions. In the aquarium this manifests as regular surface visits — completely normal and not a sign of distress unless the frequency is unusually high.
Keep in groups of two or more. Males build bubble nests at the surface during breeding season and guard the eggs with impressive dedication — a fascinating behavior in a catfish. Compatible with medium to large community fish; the Hoplo is too active and robust for nano setups.
Hardy to an impressive degree — the Marble Hoplo tolerates a wide range of water conditions, temperatures, and even temporary oxygen depletion thanks to its air-breathing ability. It is one of the toughest and most forgiving catfish available, ideal for aquarists who want a characterful, robust armored catfish.
Care & Ideal Parameters
| Difficulty | Easy |
| Temperament | Peaceful — active community fish |
| Typical Adult Size | 6.0 inches (15 cm) |
| Min. Group Size | 2 minimum |
| Ideal Temp | 64–82°F (18–28°C) |
| Ideal pH | 6.0–8.0 |
| Ideal GH | 2–20 dGH |
| Ideal KH | 1–12 dKH |
| Staple Food | Hikari Sinking Wafers; Hikari Mini Algae Wafers |
| Treat / Supplement | Hikari Frozen or Freeze-Dried Bloodworms |
| Origin | South America (wide range) and Trinidad |
| Notes | Air-breathing — must have surface access at all times. Males build bubble nests and guard eggs. Extraordinary temperature and water hardiness. Active and boisterous — not for nano tanks. |
