Mustelinus Heptapterus

Heptapterus mustelinus is native to coastal river systems of southeastern South America, particularly in Brazil and Argentina. Its elongated, smooth body with a continuous lower profile and extended adipose fin is well adapted to fast-flowing, cool, clean rivers. The common name refers to its sinuous, weasel-like body form.

In the aquarium it requires cooler temperatures than tropical catfish and does best in a subtropical or temperate setup with good oxygenation. It is a peaceful species compatible with a range of medium-sized fish adapted to similar conditions.

This species is very rarely traded but is of interest to hobbyists maintaining cool-water South American biotopes featuring species from the Pampas and Mata Atlântica ecoregions.

Water: 18–24°C, pH 6.5–7.5, moderate hardness; high oxygen, moderate to strong flow. Tank: Minimum 150L; smooth rock and driftwood décor, sandy substrate, good circulation. Feeding: Omnivore; small sinking pellets, frozen bloodworm, Tubifex, brine shrimp. Breeding: No captive breeding records. Compatibility: Peaceful; cool-water South American community fish.