South American Puffer

Colomesus asellus is endemic to the Amazon basin and its tributaries, where it lives in large schools in flooded forests and river channels. Unlike virtually all other puffer species, it is genuinely social and benefits from being kept in groups of five or more. It is an active, fast-moving species that spends time patrolling the mid-water column and requires a constant supply of snails to maintain beak health.

Water: 22–28°C, pH 6.0–7.5, soft and slightly acidic; Amazon-style conditions are ideal. Tank: Minimum 100 L for a group of five; well-planted with open swimming areas and driftwood. Feeding: Small snails (essential for beak wear), bloodworm, daphnia, brine shrimp, and tubifex. Behaviour: Active and schooling; far less aggressive than other puffers but will still nip slow tankmates. Compatibility: Best in species groups; can be kept with fast, robust dither fish in well-structured tanks.