Pufferfish generally share basic characteristics, including their signature defense of puffing up like a ball when threatened. Many of the species also share spines that cover their body and tetrodotoxin in their skin and organs. However, the toxins come from their diet and there are plenty of species that do not have spines or pronounced spines.
Instead, most owners should focus on temperament as an indicator of safety. There are several pufferfish species that are peaceful, and therefore safe, including both freshwater and saltwater species.
1. Pea Pufferfish
Pea Puffers (Carinotetraodon travancoricus) are the smallest pufferfish in the world and in the domestic fishkeeping hobby. They are also one of the few freshwater puffers, making them more accessible for beginners to the trade. You may also see them referred to as Dwarf Pufferfish, Dwarf Pea Puffers, Malabar Puffer, and Pygmy Pufferfish. Interestingly, this is a distinctly separate species from the Imitator Puffers (Carinotetradon imitator), which are also known as Dwarf Malabar Puffers—see the next section for more on this puffer.
Pea Puffers are one of the safest types of pufferfish to own. Arguably, due to their size, they are the safest variety. Pea Puffers top out around 1.4 inches, maximum, but most stay around 1 inch. Their tiny size makes them one of the best fish for a small aquarium. Although they can be aggressive to each other and similarly-sized tankmates, they are harmless to humans.
As your Pea Puffers grow older and more confident, they will become accustomed to you and your habits. This means that they may come up to you during feeding times or when you clean the tank. This curiosity is interesting and safe; they will not bite or otherwise attack humans. And, even if they did try to bite you, their diminutive size prevents them from doing any damage.
2. Imitator Pufferfish
Imitator Puffers (Carinotetradon imitator) are extremely similar to Pea Puffers. The primary difference between Pea Puffers and Imitator Puffers is that the latter tend to have more yellow colorations with less spots or patterns. Like the variety they emulate, Imitator Puffers can be aggressive with each other and tankmates but are harmless to humans.
To help with aggression in tankmates, Imitator Pufferfish should either be housed alone or provided with ample space. Females can be housed together, as can one male and several females, provided that they can each carve out a “territory” of sorts in your tank. Plants, décor, and hides to break up sightlines also help reduce in-fighting.
Regardless of their fish-directed aggression, Imitator Pufferfish will not bite or otherwise harm humans. As such, Imitator Pufferfish are one of the safest types of pufferfish to own. Should you be interested in them, carefully examine the stock in your local fish store: these are often confused with Pea Puffers and tend to be more rare. Regardless, like Pea Puffers, Imitator Puffers are one of the most unique freshwater fish you can add to your aquarium.
3. Dogface Pufferfish
For anyone who wants a peaceful saltwater puffer, the Dogface Pufferfish (Arothron nigropunctatus) is the perfect option. Also known as the Black Spotted Pufferfish, this species is also much larger than the other options in this article and can grow up to 13 inches. The Dogface Puffer is not a threat to humans and is similarly only aggressive toward other fish if provoked.
While more solitary, the Dogface Puffer’s sedate nature can be maintained in community environments. This species eats invertebrates and coral alike, meaning that aquariums with these inhabitants will provoke more aggression from the Dogface. By avoiding these, stocking peaceful fish, and maintaining correct tank parameters, owners will reap the benefits of one of the safest pufferfish.
Despite their larger size, the Dogfish Puffer is not a threat. What makes a pufferfish dangerous is its presence in the wild, its diet that produces toxins, and presence of spines.
4. Amazon Pufferfish
The Amazon Puffer (Colomesus asellus) is a freshwater pufferfish that remains small (typically 6 inches or less) and is relatively peaceful. Though it is often categorized as semi-aggressive, the Amazon Pufferfish typically has peaceful disposition toward tankmates and humans. Even if the Amazon Pufferfish does chase a tankmate, they are extremely unlikely to bite or try to eat other fish. Similarly, they are usually docile with their owners and other humans.
To reduce any possible aggression, this pufferfish variety should be kept in a group of at least six spread out across 30 gallons or more. If you want a mixed-species tank, the other fish and invertebrates should be quiet and not prone to harassment. As with the other puffer species, breaking up sightlines and providing the inhabitants with many places to hide will promote a peaceful environment. These conditions will bring out the Amazon’s Pufferfish’s natural behaviors, which rank among the top of fish with huge personalities.
5. Spotted Congo Pufferfish
The Spotted Congo Puffer (Tetraodon schoutedeni) is a freshwater puffer species that stays on the smaller end, around 4 inches at maximum. This species is peaceful toward humans but can be semi-aggressive toward tankmates. Importantly, this is a separate species from the Congo Puffer (Tetraodon miurus), which is incredibly aggressive.
However, their social tendencies can be promoted in a community environment, should the right conditions be met. Providing plenty of space helps, at least 30 gallons, but ideally more in a mixed-species tank. Soft lighting promotes peaceful behavior, as does breaking up sightlines and offering a sandy substrate. All of this will emulate their natural environment, putting them at ease.
Additionally, the Spotted Congo Puffer has a voracious appetite that includes tendencies to gnaw on plants. Providing live plants and a variety of hearty foods (including snails) will keep the Spotted Congo Puffer from becoming hangry.
