Amazon puffer

Colomesus asellus

Also known as South American Puffer

FreshwaterFish

Amazon puffer (Colomesus asellus) — Imperial Tropicals · Used with permission

Care at a glance

Temperature: 72–82°F; 22–28°C
pH: 6.0–7.5
Adult size: 4.7 in; 12 cm
Minimum tank: 26 gal; 100 L

Temperament: Mostly peaceful
Social behavior: Shoaling
Tankmates: With caution
Swim level: Middle
Diet: Carnivore
Difficulty: Difficult
Breeding: No record
Rarity: Rare
Family: Tetraodontidae
Origin: Brazil, Colombia, Peru, Ecuador

Overview

The Amazon puffer is a busy, active puffer that spends the day cruising open water rather than lurking. It is a puffer for experienced keepers.

Did you know

The Amazon puffer grows its beak-like teeth faster than almost any other freshwater puffer. If it cannot grind them down on snails and other hard-shelled food, the teeth can overgrow until it cannot eat. Keepers sometimes have to trim them by hand.

Caring for the Amazon puffer

Unusually for a puffer, the Amazon puffer does best in a group and turns nervous when kept alone. Plan on a small shoal of five or more in at least 26 gal (100 L), since a group needs plenty of swimming room. Open swimming space matters more than heavy decor. Keep driftwood and some planted areas to the sides, so the group has room to patrol the middle.

Unlike many brackish puffers, it is a true freshwater fish and never needs salt. Give it clean, well-oxygenated water with a gentle to moderate current. Keep it at 72 to 82°F (22 to 28°C) and a pH of 6.0 to 7.5.

Its teeth grow constantly, so a steady diet of hard-shelled prey is essential. Feed pond and ramshorn snails, small clams and mussels, and frozen shrimp to wear the teeth down.

Amazon puffers can be nippy, so keep them as a species group or only with fast, robust tank mates, and watch for fin-nipping. Aquarium breeding is essentially undocumented, and almost all fish in the trade are wild caught.

Good to know

The Amazon puffer belongs to the family Tetraodontidae, the true puffers, whose four fused teeth form a hard, beak-like plate. Like all puffers, it can gulp water to inflate into a ball when threatened. It lacks scales and normal ribs.

In the wild

The Amazon puffer comes from the large river systems of Brazil, Colombia, Peru and Ecuador. It roams flowing channels and follows the seasonal floods.

Common questions

What size tank does an Amazon puffer need?

An Amazon puffer needs at least 26 gal (100 L). It spends most of its time in the middle.

What temperature and pH does an Amazon puffer need?

An Amazon puffer is comfortable at 72–82°F (22–28°C) with a pH of 6.0–7.5.

What does an Amazon puffer eat?

An Amazon puffer eats hard-shelled prey such as pond and ramshorn snails and small clams and mussels, plus frozen shrimp. These foods wear down its constantly growing teeth.