Amazon Puffer

The Amazon puffer is recognized by the thick black bands crossing its yellowish-green back. It is the only common puffer in South America that lives entirely in fresh water; although it was long thought to be a brackish fish, it does not need salt.

Its biggest difference from other puffers is that it is active and social: instead of lying in ambush in a corner, it roams the aquarium all day, likes swimming against the current and lives in loose groups in the wild. It stays at 8–10 cm.

It lives in the rivers of the Amazon basin, in flowing stretches with sand and gravel bottoms, and in floodplain lakes. Snails and small crustaceans in the water are its main food.

• Volume: at least 150 liters and 100 cm length for a group of 3–5; 80 liters for a single fish.
• Flow: moderate flow and plenty of oxygen; leave open swimming space.
• Water: 25–27°C, soft to moderately hard; it is sensitive to nitrate buildup, so do a 30% water change weekly.
• Decor: roots and stones along the edges, open space in the middle. It does not eat plants.

Carnivorous. Snails should be the basis of the diet; they wear down its teeth and allow natural hunting behavior. Vary with frozen bloodworms, mysis, brine shrimp and small shell-on shrimp. Because it is active, it is fed small amounts more often than other puffers, 1–2 times a day.

Curious and lively. Brief chases occur between individuals in a group, but serious injuries are rare. It tends to nip the fins of other fish.

Good companions: it is best kept with its own kind. In a large aquarium it can be tried with fast, short-finned species too big for its mouth (large tetras, Geophagus).

Avoid: shrimp and snails (they become food), long-finned and slow species, very small schooling fish.

A single fish can live alone, but in a group of 3–5 it behaves more naturally and its aggression is spread among its conspecifics. Add the group to the aquarium at the same time.

Aquarium breeding has rarely been reported; it is thought to lay its eggs among plants or on the substrate. Most fish sold are wild-caught.

• Internal parasites and wasting: common in wild-caught fish; quarantine is recommended.
• Overgrown teeth: in fish not given snails.
• Medication sensitivity: its scaleless skin is sensitive to copper.

There is no reliable external way to tell the sexes apart.