South American Puffer

Colomesus asellus

Animalia›Chordata›Actinopterygii

📍 South America

The only truly schooling freshwater puffer, native to the Amazon basin, displaying a small (2 inch) body with an attractive olive-green and yellow pattern and a comparatively mild disposition relative to other puffers. Unlike most puffer species, it can be kept in groups of 6+ and even in peaceful community tanks with fast-moving, robust tankmates; it still requires meaty foods and occasional hard-shelled prey to manage tooth growth.

Size3.5"

Min Tank30g

School3+

semi-aggressive

Zonemid

Care Guide

Diet

South American Puffers are carnivorous and require a varied diet of meaty foods including frozen bloodworms, brine shrimp, and small crustaceans once daily. They must be offered hard-shelled prey such as small snails or crushed crayfish weekly to naturally wear down their continuously growing teeth and prevent dental overgrowth.

Behavior

These are the most social puffer species and thrive in groups of 6 or more, displaying schooling behavior and reduced aggression compared to solitary puffers. They are active mid-water swimmers with curious, playful personalities, though they may still nip at slower-moving fish or investigate tank mates with their mouths.

Breeding

Breeding in captivity is difficult and rarely achieved in home aquariums; spawning requires very specific conditions including dense vegetation, slightly acidic water, and careful pair selection. Fry are extremely small and require infusoria and microscopic foods, making successful rearing challenging for most hobbyists.

Tank Mates

Diamond Tetra

Fast-moving, robust tetras that can coexist with puffers; similar water parameters and peaceful community preference

good

Emerald Dwarf Rasbora

Small, active rasboras that stay in groups and move quickly enough to avoid puffer aggression

good

Bristlenose Pleco

Nocturnal bottom-dweller that occupies different tank zone; hardy and unlikely to be bothered by puffers

excellent

Otocinclus

Small algae eaters that may be nipped; only suitable in larger groups with well-fed puffers

caution

Rummy Nose Tetra

Schooling fish with fast movement patterns that reduce predation risk in community settings

good

Common Diseases

Ich (Ichthyophthirius multifiliis)

Symptoms

White spots on body and fins, rapid breathing, flashing against objects, lethargy

Treatment

Raise temperature gradually to 28-30°C, perform daily 25% water changes, use aquarium salt (1 teaspoon per 5 gallons) or commercial ich treatment; maintain for 10-14 days

Fin Rot

Symptoms

Frayed or deteriorating fin edges, discoloration, fin loss progressing toward body

Treatment

Improve water quality with frequent partial water changes, reduce stocking density, treat with antibacterial medication if severe; ensure water parameters remain stable

Dental Overgrowth

Symptoms

Difficulty eating, mouth deformity, inability to close mouth properly, weight loss

Treatment

Provide hard-shelled foods (snails, small crayfish) weekly to naturally wear teeth; severe cases may require manual filing by experienced aquarist

Parasitic Infections

Symptoms

Excessive scratching, visible parasites, cloudy eyes, loss of appetite, weight loss

Treatment

Quarantine affected fish, treat with anti-parasitic medication, perform frequent water changes; improve tank hygiene and avoid introducing infected stock