Amazon Puffer 101: Care, Diet, Tank Size, Tank Mates & More

Don’t you just hate it when you buy a fish, and it dies shortly afterwards? We can relate! This is all too common, but you might be spared from this heartbreak if you take the time to learn everything about that fish before buying it.

So, if you’re thinking about getting an Amazon Puffer, read this guide. We will detail what to feed them, what size tank they need, and what tank mates they can live with. We will also share some interesting facts about these amazing fish, so be sure to read on!

Species Summary

Amazon Puffer

The first thing you need to know about Amazon Puffers (Colomesus asellus) is that they are native to South America. They get their name because they often inhabit the Amazon River basin. They also belong to the Tetraodontidae family, which includes other well-known fish such as pufferfish and triggerfish.

You can find Amazon puffers in waters with high levels of oxygen. These include sandbanks, floodplain lakes, banks with overhanging vegetation, and fast-flowing water over rocks and stones. As you might have guessed, this species of puffer lives 100% of its life entirely in freshwater, unlike other species marketed as freshwater pufferfish, but need brackish water to live with quality.

The Amazon pufferfish is considered one of the world’s most knowledgeable and curious fish. These fish react spontaneously to specific situations, making them sought-after fish. They also have playful personalities and a love of swimming in groups.

What’s more, Amazon Puffers have a habit of inflating in dangerous situations. This behavior doesn’t go unnoticed, and it’s one of the reasons why Amazon Puffers are so popular.

Its unique appearance makes the Amazon Puffer more attractive, with its pectoral fins moving quickly back and forth. This gives the illusion that it’s “flying” in the water. 

The constant movement of its eyes also often doesn’t go unnoticed. It’s not evident in other species and gives the false impression of the fish sketching—physiognomic expressions.

Amazon Puffer Care Guide

Like all fish, Amazon Pufferfs require proper care and feeding to thrive. This section of the guide will discuss how to care for these little guys. 

Tank Size

Amazon Puffers spend most of their time swimming around the aquarium, searching for food, or lurking in the vegetation. Because of that, they need an adequately generous tank in which they can swim freely. A 48″ x 12″ aquarium or somewhere around 28 gallons will suffice for an individual or small group.

But then again, space is at a premium in today’s homes, which goes for fish tanks. A larger tank allows more room to swim and feed, leading to happier and healthier Amazon Puffers.

Tank Mates

You can keep Amazon Puffers with other fish, but they’re not the best tank mates. They’re known to be nippy, so they can harass and even injure other fish with flashy and exuberant fins. Unfortunately, they’re also very active so that they can compete with other fish for food.

If you decide to keep them with other fish, choose peaceful species that are fast-swimming and short-finned. Good choices include:


● Otocinclus Catfish

Kuhli Loach

● Siamese Algae Eaters

Same Species Tanks

Amazon Puffers are often used as a single species in Biotope-type aquarium setups, where the original location of the species is imitated. By imitating the original location and environment of the Amazon Puffer Fish, many hobbyists believe they provide a more natural experience for their pet fish.

Given its behavior and relative fragility, we recommend keeping only this species in the aquarium.

Water Parameters

These fish are resistant to many environmental factors but are not immune to sudden changes in water parameters. They can also die when exposed to pollutants in the water, low availability of oxygen, and accumulation of organic matter in the aquarium.

But the good news is that these fish present themselves as an exclusive freshwater species and doesn’t require any addition of salt in their environment.

The ideal temperature for its maintenance is from 68 to 79 F. Additionally, the ideal pH range is between 6.5 and 7.5, and the hardness is between 36 and 268 ppm.

What to Put in Their Tank

One of the most important things you will need is an aquarium heater. Without one, the Amazon Puffer may be unable to maintain a comfortable temperature in its tank. And since these fish are prone to getting sick if their environment isn’t clean, the tank should also have a filtering system to remove waste and debris.

In addition to heating and filtering, a good quality substrate will also help keep your Amazon Puffer happy and healthy. They habitually turn over the substrate and rocks in the tank, so we recommend a soft substrate and rounded stones. Make sure these things are free from ends that could injure the fish.

You do not need an aquarium decor to maintain the species, but it can be beneficial to help keep your fish healthy and happy. Being active fish, driftwood and rocks are vital players in the tank, serving as Amazon Puffer’s hiding places and territories. These natural objects can also help to stimulate the fish’s appetite by creating an enjoyable environment.

Common Diseases

The Amazon Pufferfish is a highly disease-resistant fish, but their skin may be predisposed to infection because they do not have scales. The fish’s smooth skin makes them susceptible to parasitic infections, such as white spot disease (Ichthyophthirius multifiilis), flukes, costia, fish lice, Chilodonella, and Trichodina

Food and Diet

The Amazon Puffer is an omnivorous fish that will eat plant and animal material.

In its natural environment, its primary diet is based mainly on mollusks, crustaceans, and other invertebrates. However, they also eat plants and detritus.

In captivity, this fish has difficulty accepting commercial food. You can supplement their diet with live and fresh foods such as shellfish, worms, small fish, and crustaceans. It is essential to offer a variety of foods to these fish, as this will ensure they receive all the nutrients they need.

An inappropriate diet without shells or hard elements can cause their plaques/teeth to grow too much. These plaques are constantly increasing and must be used up through these foods. Once its teeth/plates are large, the fish may not open its mouth if it dies of starvation. You must intervene by cutting the plates manually if it reaches this stage.


When it comes to Amazon Puffers, 3-5 years is about the average lifespan. This is provided that all the paraments are kept stable and given a balanced diet.

In nature, their lifespan is short, and they often die young due to diseases, attacks from other animals, and environmental causes.


The Amazon puffer has a robust and eccentric body with a golden olive green base, black dorsal spots, and a white belly. Its body is elongated and oval, with a thin caudal fin between the anal and dorsal fins.

But perhaps the large eyes positioned laterally on the skull, and the five transverse dark spots positioned dorsally on the body are the puffer’s most striking features.


The Amazon Puffer can easily reach 5.1 inches in length when well cared for and fed. Usually, the average size we find in aquariums is around 3.1 inches.

Behavior and Temperament

It is a species of gregarious fish of peaceful behavior and can be kept in a community aquarium with larger or the same size pacific fish. 

They are very active animals and always observe what happens around them. They occupy practically all tank areas, mainly in mid-water and areas close to the substrate, where they prefer to eat.

Moreover, these fish naturally forms free schools, and their behavior is more natural when kept in small groups. Therefore, we recommend you keep them in several five or more. Otherwise, there may be severe persecution of the weakest of the group.

Their behavior can change if they don’t feel comfortable in the tank, hiding among vegetation, rocks, and driftwood. When left alone, the Amazon Puffer can become highly stressed or depressed. 

They can quickly kill small fish because of their bony beak despite being fragile.


There is no report of reproduction of this species in aquariums, so the animals come from the collection in a natural environment. Studies suggest an exciting mechanism in which spawning occurs in main river channels or near banks at the mouths of flooded lakes and tributaries during flood periods. The aquatic larvae are reared in floodplain lakes, where they complete their development, returning to river channels when floodwaters recede.

They are an oviparous species, so their reproduction is similar to marine pufferfish. And unlike other tetraodontids, they have high fecundity with tiny eggs. Furthermore, parents do not display parental care, and cannibalism is likely to occur on eggs.

Gender Differences: Male vs Female

There is no sexual dimorphism, so it will only be possible to define the sex of the fish just before the eggs are laid, with the externalization of the female’s ovipositor or with the female’s belly more protruding and rounded.

Amazon Puffer Fun Facts

● Puffers are gluttonous animals and eat a lot. They also need sound filtering system for maintenance and regular partial water changes.

● They developed various defense mechanisms throughout their evolution. For example, they use their propulsion, caudal, adal, dorsal, and pectoral fins when swimming, enabling them to move and swim around in a maneuverable manner yet very gradually.

● Their primary defense mechanism is the ability to swell or inflate quickly by filling their very elastic stomach with water or air when out of the water, thus doubling or tripling its size. This means of defense can deceive a potential predator.

● Some pufferfish, mainly marine species, produce a potent neurotoxin in their internal organs known as Tetrodotoxin. This neurotoxin is found primarily in the ovary and liver, and can migrate small amounts in their intestines, skin, muscle, and blood tissue. Additionally, this neurotoxin can be lethal to most predators, including humans. 

Studies carried out by researchers from Nagasaki (Japan) claim that pufferfish acquire venom when they consume toxic foods such as starfish and mollusks.

● In medicine, drugs derived from Tetrodotoxin are fully developed to relieve those suffering from severe chronic pain; experiments on cancer patients and drug addicts are also being studied.

● Their eyes can move independently and blink; in some species, they can even change the coloration or intensity of their patterns according to environmental changes and needs.

● Another defense mechanism is the thorns found on the skin of some marine species. These thorns are entirely visible, transmitting a threatening and intimidating aspect in the face of potential predators. In Amazon Puffer, its head and body are covered with small spines, which become more visible when the animal swells.

●  It would be best to feed Amazon Puffers regularly with hard shells (snails and shellfish) to wear down their teeth. Alternatively, you can also use fine limestone sand in the substrate. Their teeth will eventually wear down by chewing food captured in the substrate along with the sand.


Now that you know everything about Amazon puffers, it’s time to add one to your tank! They’re a fun and active addition that will liven up your aquarium.


Eschmeyer, W.N. (ed.), 1998. Catalog of fishes. Special Publication, California Academy of Sciences, San Francisco. 3 vols.

Kullander, S.O., 2003. Family Tetraodontidae (Pufferfishes). p. 670. In R.E. Reis, S.O. Kullander and C.J. Ferraris, Jr. (eds.) Checklist of the Freshwater Fishes of South and Central America. Porto Alegre: EDIPUCRS, Brazil.

Menezes, N.A., P.A. Buckup, J.L. Figueiredo and R.L. Moura, 2003. Catálogo das espécies de peixes marinhos do Brasil. São Paulo. Museu de Zoologia da Universidade de São Paulo, 160 pp.

Soares, M.G.M., R.G. Almeida and W.T. Tunk, 1986. The trophic status of the fish fauna in Lago Camaleao, a macrophyte-dominated floodplain lake in the middle Amazon. Amazoniana, IX(4):511-526.