South American leaffish

Monocirrhus polyacanthus

A leaf-shaped ambush predator with a small lower-lip projection

The compressed mottled body resembles a dead leaf. A lower-lip projection looks like a stalk. It approaches prey head-down and extends a large mouth.

Adult length: Up to 10 cm (standard length, without the tail fin)
Water temperature: 23–29 °C
Lifespan: 5–8 years
pH: 5–6.8
Hardness: 1–10 dGH

Natural habitat: Native to the Amazon River basin in South America.

Providing live food long-term is the main challenge. Small aquarium fish and shrimp will be eaten.

View comparison →

Appearance and identification

It is not an enlarged Badis or Dario. Its deep leaf shape, lip projection and strong fish-eating habit set it apart. South American, African and Asian leaffishes differ and need separate care.

Social behaviour and territory

Keep in a dedicated setup. Male egg care does not mean a peaceful permanent pair.

Compatibility limits

Prey size matters more than overlapping water ranges. Small tankmates will be eaten.

Space requirements

Provide mature soft, acidic water, gentle flow and shaded broad-leaf cover. A 75 × 30 cm footprint is a reference.

Aquarium environment

Broad leaves give concealment and spawning sites. Keep water quality good and feeding observable.

Diet and feeding

Needs live prey; do not assume pellets or frozen food will be accepted. Confirm feeding and a sustainable supply before purchase.

Sources

www.fishbase.se ↗ 2026-10-25

www.seriouslyfish.com ↗ 2026-10-22

api.gbif.org ↗ 2026-10-22