Species Snapshot
- Species Name: Carinotetraodon travancoricus
- Common Names: pea puffer, dwarf pufferfish, Indian dwarf puffer, pygmy puffer
- Size: Up to 1 inch
- Lifespan: 2-6 years
- Native Distribution: Southwest India
One of the most unique fish for small freshwater aquariums is the pea puffer (Carinotetraodon travancoricus). Also known as Indian dwarf puffers, pea puffers are endemic to Kerala in Southwest India. What makes them unique from other pufferfish is their diminutive size and the fact that they’re a freshwater species.
If you’re looking for an attractive and entertaining species to feature in a freshwater nano tank, consider the pea puffer. Here’s what you need to know about them.
Anatomy and Appearance
Known by many names, these miniature pufferfish grow to a maximum length of around 1 inch with round, oblong bodies. Pea puffers are greenish-yellow in color with iridescent patches of dark green, brown, or black color on the sides and back. These pufferfish have small, fanlike pectoral fins with short, round dorsal and anal fins.
Like other pufferfish, pea puffers can ingest air to puff themselves up as a defense mechanism. Pea puffers don’t have scales like many fish, but they do have skin spines that stick out when they inflate. Inflating makes the pufferfish harder to swallow but the process can be tiring, so it’s best not to force your pufferfish to inflate.
Ideal Aquarium Setup
Because they are prey animals in their native environment, pea puffers prefer a tank setup that offers plenty of places for them to hide. It’s also important to mimic the water chemistry of the species’ native habitat.
Tank Size
Though pea puffers only grow up to 1 inch long, they’re a very active species that requires a minimum of 5 gallons of water volume for a single fish. Because pea puffers do best in groups, however, bigger tanks are better. When properly maintained, a 15- to 20-gallon tank can safely accommodate a group of 6 pea puffers.
Water Parameters
Native to freshwater rivers in Southwest India, pea puffers prefer warm, slightly alkaline water. Unlike many pufferfish species, pea puffers are completely adapted to fresh water—there’s no need to add aquarium salt to create a brackish tank environment.
The ideal water parameters for pea puffers are:
- Temperature: 72-80°F
- pH: 6.8-7.8
- Gh: 8-16
- Kh: 4-7
- TDS: 180-250
Most pea puffers available in the aquarium trade are captive-bred, so they may be more adaptable to various tank conditions than wild-caught specimens. Even so, it’s best to mimic the species’ native environment as closely as possible when designing your tank.
Tank Décor
A lushly planted tank is ideal for pea puffers, especially if you plan to keep more than one in the same tank. Pea puffers can be aggressive with others of their species, so having plenty of aquarium plants to hide in helps prevent fighting. Having plenty of plants also makes pea puffers feel more secure in the tank.
There are many ways to decorate a pea puffer tank but natural décor schemes tend to be the most suitable. In addition to driftwood and rockwork, include a mix of rooted and floating plants. Floating plants give your pea puffers places to hide and break up sightlines to help reduce aggression.
Diet and Feeding
Pea puffers are carnivores but their size limits the kind of food they can eat. In the wild, pea puffers consume insect larvae and small crustaceans.
Pea puffers in captivity should be fed a varied diet of freshwater snails, small shrimp, and other fresh or frozen meaty foods like mussels and shellfish. Some pea puffers will eat live or frozen insect larvae like bloodworms.
Temperament and Tank Mates
Unique from other pufferfish species, pea puffers are highly social. They can often be found in large groups called shoals in their native environment. In captivity, however, it’s important to consider tank size when keeping more than one pea puffer. A group of 6 or more is ideal, as smaller groups may be more prone to infighting.
Pea puffers are notorious fin nippers that tend to do best in species-only tanks. If you are determined to house them with other fish, choose small, short-finned, fast-swimming species. Avoid bottom-dwellers like Corydoras and Plecostomus which might interfere with the pea puffers’ preferred hiding spots.
Breeding Pea Puffers
Whether you plan to breed your pea puffers or not, it’s ideal to maintain a ratio of at least two females for every male. Male pea puffers tend to be more aggressive and territorial than females, so it’s best to keep as few males in the group as you can.
Unfortunately, it’s tricky to sex pea puffers when they’re young. Sexually mature male pea puffers have a dark line running along their underside as well as a pattern of closely spaced lines around the eyes that look something like wrinkles. Adult female pea puffers tend to have a rounder body shape than males.
To encourage your pea puffers to breed, be sure to provide plenty of moss in the tank. During spawning, the female pea puffer will scatter up to 5 eggs in the moss and the male will follow behind to fertilize them. The pair may then leave the spawning site for a brief period, but the male will then generally return to guard the eggs until they hatch after about 5 days. The pair may spawn multiple times over several days.
Other Interesting Facts
- The pea puffer looks very similar to the closely related dwarf Malabar pufferfish (Carinotetraodon imitator). In fact, the latter wasn’t recognized as a separate species until 1999.
- Like other pufferfish, pea puffers can inflate when they feel threatened. Their bodies also produce a toxin that makes them poisonous to predators, but they don’t release the toxin into the water.
- Pea puffers are very intolerant of poor water conditions, so proper filtration and frequent water changes are a must for this species. Aim to keep nitrate levels below 15 ppm with ammonia and nitrite levels at 0 ppm.