Pea Puffer
Carinotetraodon travancoricus
The world's smallest pufferfish, a curious freshwater nano fish full of personality.
| Difficulty | Intermediate |
| Min. Tank Size | 20 L |
| Temperature | 22.0–26.0 °C |
| pH Range | 6.5–7.5 |
| Max Size | 2.5 cm |
| Lifespan | 3-4 years |
| Diet | Carnivore |
| Temperament | Semi-aggressive |
Overview
The Pea Puffer (Carinotetraodon travancoricus) is the world's smallest pufferfish, a curious freshwater nano fish full of personality. It is a popular choice among Australian aquarists, reaching around 2.5 cm and living roughly 3-4 years when properly cared for.
This complete guide covers how to keep the Pea Puffer successfully - tank size and setup, water parameters, the best foods (including recommended brands), suitable tank mates, breeding, sexing and the health issues to watch for. It is rated Intermediate to care for.
Natural Habitat & Origin
Pufferfish come from rivers, estuaries and lakes across Africa and Asia. They are intelligent, curious and messy, with beak-like teeth that grow continuously and must be worn down on hard-shelled foods.
Matching the temperature, water chemistry and cover a species evolved with is the simplest route to keeping it healthy and seeing its natural behaviour and colour.
Tank Size & Aquarium Setup
Provide a minimum of 20 litres for the Pea Puffer. As a group-living species, swimming length and floor space matter more than height.
A tight-fitting lid is essential - this species is a capable jumper.
Live plants, driftwood and shaded retreats give security and show off the fish's colours against a natural backdrop.
Always add fish only to a fully cycled, mature tank with stable biological filtration. Match filtration generously to the fish's size and waste output.
Water Parameters
Keep the Pea Puffer in stable water at 22-26 °C with a pH of 6.5-7.5. It adapts to a moderate range, so stability matters more than an exact figure.
Test regularly: ammonia and nitrite must read zero, and nitrate should be kept low with routine partial water changes. Always dechlorinate and temperature-match new water, because sudden swings cause far more illness than water that is stable but slightly imperfect.
Diet & Feeding
The Pea Puffer is a carnivore and needs a protein-rich, meaty diet.
In Australia, good options include hard-shelled foods to wear down their teeth - ramshorn and Malaysian trumpet snails, plus Dymax frozen bloodworm, krill, mussel and clam. Feed small amounts once or twice a day (only what is cleared in a minute or two), vary the diet for the best colour and health, and avoid overfeeding, which is the leading cause of poor water quality.
Temperament & Tank Mates
The Pea Puffer is semi-aggressive: generally community-tolerant but territorial at times, especially when breeding or under-stocked. Avoid very small, slow or long-finned tank mates and give everyone space.
It is happiest in a group of its own kind and is shyer and less settled when kept alone.
Breeding
The Pea Puffer is an egg-scattering species. To breed it, condition a group on rich foods, then move them to a dim tank with fine-leaved plants or a spawning mop; the parents scatter eggs and will eat them, so remove the adults after spawning.
Even if you are not planning to breed it, recognising this behaviour helps you understand what you are seeing and respond well - for example by adding cover for fry or giving a guarding pair extra space.
How to Tell Males from Females
Most puffers are very difficult or impossible to sex visually; differences, where they exist, only show in mature breeding fish.
Common Health Problems
Puffers are scaleless and sensitive to medication and poor water; overgrown teeth (from a lack of hard foods) and constipation are common, avoidable problems. Quarantine new arrivals for 2-4 weeks and watch daily for early signs such as loss of appetite, unusual hiding, clamped fins or laboured breathing - caught early, most issues are very treatable.
Prevention beats cure: keep water pristine, avoid overstocking and overfeeding, quarantine new arrivals, and act at the first sign of trouble.
Is the Pea Puffer Right for You?
The Pea Puffer suits keepers with some experience and a stable, mature, appropriately sized tank, as long as you can provide at least 20 litres, water at 22-26 °C and pH 6.5-7.5, the right diet and a proper group of its own kind.
Meet those needs and the Pea Puffer will reward you for around 3-4 years. Use our free aquarium calculators to plan your setup, and explore our other fish, plant and disease guides to build a thriving aquarium.