Amazon Puffer (Colomesus asellus)

The Amazon Puffer (Colomesus asellus) is one of the only true freshwater puffers in the hobby, a big-eyed, banded little character with far more personality than its three-inch size suggests. Unlike most puffers, which need brackish or marine water, the Amazon Puffer lives its entire life in freshwater, and it is one of the rare puffers happy to live in a group. It is an active, curious, intermediate-care fish. Browse the rest of our freshwater fish.

Care Guide

Amazon Puffers are constant, energetic swimmers, so give them a long tank with open room, ideally 30 gallons or more for a small group. They are one of the few puffers that actually do better in numbers: a group of four to six spreads out their energy and reduces nipping. Keep the water warm and clean at 74 to 82 F, pH 6.5 to 7.5, with strong filtration since puffers are messy eaters. The single most important rule is diet: their beak grows continuously and must be worn down with hard-shelled foods like snails and clams, or it will overgrow and stop them from eating. Like all puffers they are scaleless, so introduce them to an established tank and dose any medications with extra care.

Specifications

Compatibility

Amazon Puffers are happiest kept together in a group of their own kind, which is unusual and one of the best things about them. For tankmates, choose fast, robust fish that can hold their own and will not be nipped. Avoid slow or long-finned fish, and remember that puffers will hunt and eat shrimp and small snails, so they are not a good fit for a shrimp tank or a prized snail collection.

Treat smaller snails as food rather than tankmates: a steady supply is exactly what keeps a puffer's beak healthy.

Recommended Foods & Supplies

Feed a varied carnivore diet, and make sure hard-shelled items are a regular part of it to wear down the beak.

• Hard-shelled snails are the classic puffer snack: Japanese Trapdoor Snails and small nerite snails help keep the teeth trimmed.
• Round out the diet with frozen and meaty foods like bloodworms, clams, and mussels.
• Stock up on cleanup snails from our freshwater invertebrates collection.
• See another fun species, the Indian Pea Puffer.

FAQ

Is it really 100% freshwater?
Yes. Most puffers need brackish or saltwater, but the Amazon Puffer is a true freshwater species and needs no added salt.

Can I keep more than one?
Yes, and you should. It is one of the few shoaling puffers and does best in a small group of four to six.

Why does it need snails and hard food?
A puffer's beak grows continuously. Crunching hard-shelled foods keeps it filed down so the fish can keep eating.

Is it safe with shrimp and other fish?
It will eat shrimp and small snails and can nip fins, so choose fast, robust tankmates and skip the inverts you want to keep.