Pea Puffer Carinotetraodon travancoricus

Quick Stats

Tank Setup

The Pea Puffer (Carinotetraodon travancoricus), also called the Indian Dwarf Puffer or Malabar Puffer, is the smallest pufferfish in the hobby — and the most personality per square inch of any fish I keep. A 10 gallon tank is the realistic minimum for a single specimen, or a 15–20 gallon for a harem group of 1 male and 2–3 females. They come from slow-moving rivers and backwaters in the Western Ghats of India, where they hunt snails and insect larvae among dense vegetation.

Maintain water parameters within: temperature 22–28°C, pH 6.5–7.5, hardness 5–12 dGH. They tolerate a wider range than most puffers and adapt to moderately hard tap water without issue — which is a big part of why they are the easy-care puffer. The one thing they will not forgive is poor water quality: as a high-protein carnivore they produce a lot of ammonia relative to their size, and a 10 gallon tank will spike nitrate fast without weekly water changes. I run my pea puffer tank at 25°C, pH 7.0, GH 8, with a 30% water change every week without exception.

Set up the tank with sand or smooth fine gravel, driftwood, and dense planting along the back and sides — Java fern, Anubias, Vallisneria, and floating plants. Break the sight lines: a pea puffer that can see another pea puffer across an open tank will harass it constantly. Caves, PVC pipes hidden under driftwood, and tall plants break territories and reduce aggression. A sponge filter is plenty and avoids the intake risk that comes with hang-on-back filters — puffers are curious and will investigate anything. Strong lighting brings out the green-yellow colour; dim lighting makes them go dark and hide.

Tank Mates

Pea Puffers are territorial, nippy, and predatorily curious — they will bite the fins of slow-moving fish and hunt anything small enough to swallow. That makes the tank mate list short and the species-only tank the safest option. I keep mine solo in a 10 gallon and would not add anything else to that tank.

Compatible tank mates (in a 20 gallon or larger with heavy planting): Ember Tetras, Chili Rasboras, Celestial Pearl Danios, Harlequin Rasboras, Otocinclus, and Nerite Snails (large enough to be safe from a 2.5 cm puffer). Avoid shrimp (Cherry and Amano will be hunted and eaten, possibly within days), bettas (puffers bite their fins), guppies (long fins invite nipping), any slow or long-finned fish, and any fish small enough to swallow. Avoid other puffer species entirely — pea puffers are best kept with their own kind or alone.

For multiple pea puffers, the rule is 1 male to 2–3 females in a 15–20 gallon with broken sight lines and at least three caves. Two males in any size tank below 30 gallons will fight and one will be killed. Sexing is reliable once they are mature at 4–6 months: males have a dark vertical belly stripe through the eye and brighter yellow-green colour, females are rounder with a yellowish belly and spottier pattern. If you cannot sex them, keep a single specimen — it is the lowest-stress option and the fish will not be lonely.

Diet & Feeding

Pea Puffers are carnivores with a fast-growing beak (fused teeth) that must be worn down by crunching hard-shelled prey. The single most important thing you can do for a pea puffer is feed it snails — pond snails, bladder snails, and ramshorn snails 2–3 times a week. Malaysian trumpet snails are too hard-shelled for small puffers to crack and should be avoided. Without snails, the beak overgrows, the puffer cannot eat, and it starves — a slow, ugly death that requires manual beak trimming with cuticle nippers to fix.

Feed small amounts twice daily. The core diet is frozen bloodworms, frozen brine shrimp, live blackworms, and live or frozen snails. I keep a small bladder snail colony in a 2.5 gallon jar and add a handful to the puffer tank twice a week. Frozen bloodworms are a daily staple; live blackworms are a conditioning food for breeding. Avoid dry food entirely — most pea puffers refuse flakes and pellets, and even those that accept them do not get enough beak wear from soft prepared food.

Target-feed with a turkey baster or feeding tongs. Pea puffers are messy eaters and uneaten bloodworms rot fast in a 10 gallon tank. Feed what they can hunt down in five minutes, then siphon the rest. They recognise their owner within weeks and will beg at the front glass when you walk in — the eyes follow you across the room, which is both charming and slightly eerie. They learn feeding routines fast and will spit sand at the surface if you are late.

Common Health Issues

Pea Puffers are hardy once established but they have three specific failure modes that beginners hit over and over. The first is beak overgrowth from a snail-free diet — the beak grows continuously, the puffer cannot close its mouth, it stops eating, and it starves over weeks. The fix is prevention: feed snails 2–3 times a week. The cure for an overgrown beak is manual trimming with cuticle nippers, which is genuinely difficult and stressful for both fish and aquarist.

The second issue is internal parasites. Wild-caught pea puffers (which is most of them — captive breeding is rare) carry nematodes and tapeworms that bloom under the stress of shipping. Symptoms include weight loss despite eating, stringy white faeces, and a hollow belly. Treat with praziquantel (Prazipro) and levamisole on a quarantine protocol — every new pea puffer should be dewormed in quarantine before joining the display tank. The third issue is ich from temperature swings, treated with malachite green at half dose (puffers are sensitive to copper and full-dose formalin).

Prevention is straightforward: stable temperature (24–26°C), weekly 30% water changes with dechlorinated water, snails in the diet, deworming in quarantine, and never adding a new puffer to a display tank without two weeks of isolation. Pea puffers typically live 3–5 years in good conditions, with the upper end coming from pristine water, snails in the diet, and a single-specimen tank. They are unforgiving of skipped water changes in a 10 gallon — the ammonia and nitrate climb fast.

Breeding

Pea Puffers are egg-layers and breed readily in a species-only harem tank. Set up a 20 gallon with 1 male and 2–3 females, dense planting, and flat rocks or broad plant leaves (Java fern works well) for spawning. Condition the group with live blackworms and frozen bloodworms for two weeks; the female should swell visibly with eggs.

Spawning happens in the early morning. The male courts the female with an intensified colour display and a quivering dance; if she is receptive, she lays 5–20 adhesive eggs on a flat leaf or smooth rock and the male follows to fertilise them. The female may lay eggs across several days in batches. Remove the adults after spawning — they will eat eggs and fry given the chance — or move the egg-laid leaf to a separate container with an air-driven sponge filter and methylene blue to prevent fungus.

Eggs hatch in 5–7 days at 25°C. Feed the fry infusoria or commercially-prepared liquid fry food for the first three days, then graduate to vinegar eels and freshly-hatched baby brine shrimp. Pea puffer fry are tiny — smaller than a grain of rice at hatch — and grow slowly, reaching 1 cm in about eight weeks and sexual maturity at 4–6 months. This is a rewarding breeding project for an experienced aquarist, but captive-bred pea puffers are rare in the trade; most fish in shops are wild-caught from India. Breeding them at home genuinely reduces pressure on wild populations.

Frequently Asked Questions