Pea Puffer (Carinotetraodon travancoricus)

Common Name

Pea Puffer, also called the dwarf puffer or Malabar pufferfish.

Origin and Habitat

This tiny freshwater puffer is endemic to southwest India, with records centered in Kerala and southern Karnataka in the Western Ghats region. In nature it is associated with slow to sluggish inland waters with dense vegetation, especially along calmer margins where leaf litter, roots, and aquatic plants create shelter and hunting lanes.

Biotope

If you want a true Kerala inspired setup, think shallow edges with gentle flow, warm water, and a jungle of plants. The goal is cover everywhere, plus lots of surfaces that grow micro life and hold small snails.

Biotope fish, common and easier to source

• Malabar danio, Devario malabaricus
• Striped panchax, Aplocheilus lineatus
• Filament barb, Dawkinsia filamentosa
• Melon barb, Haludaria fasciata
• Sucker fish, Garra mullya

Biotope fish, rarer Western Ghats picks

• Denison barb, Sahyadria denisonii, a famous Western Ghats endemic that is more of a fast water fish, included here as a true region reference
• Western Ghats loaches in genera such as Mesonoemacheilus, often locality specific and not always available

Biotope plants, common and useful

• Hydrilla, Hydrilla verticillata
• Tape grass, Vallisneria spiralis
• Floating heart, Nymphoides hydrophylla
• Water lettuce, Pistia stratiotes

Temperature and Water Conditions

Aim for stable, clean freshwater conditions with gentle flow. A temperature around 74 to 82 F, which is 23 to 28 C, suits most home setups. This species is often kept in neutral to moderately alkaline water. Chasing perfect numbers is usually less important than keeping ammonia and nitrite at zero, maintaining low nitrate, and providing heavy cover. If you decide to breed them, stability still matters more than extremes.

Appearance and Size

Pea puffers stay tiny, but they do not act tiny. They are yellow to olive with dark blotches that vary from fish to fish, and they have bright, expressive eyes that track movement like a little underwater hawk.

Adults are commonly listed at about 3.5 cm, roughly 1.4 inches total length, though some references note smaller typical sizes.

Male and female differences

• Males are usually slimmer, often show a dark line along the belly, and may develop subtle iridescent wrinkle like markings around the eyes.
• Females are usually rounder, especially when full of eggs, and typically lack the strong dark belly line.

Diet in the Wild

In the wild, pea puffers feed as micro predators, picking off small invertebrates. Snails, insect larvae, and other tiny prey make up the kind of menu their body and teeth are built for.

Feeding in Captivity

Plan on offering meaty foods. Frozen options like bloodworms and brine shrimp can work, but many pea puffers thrive best when they also get live foods.

A practical feeding rhythm

• Small snails, offered regularly, help satisfy natural hunting behavior and provide tooth wear.
• Live or frozen worms and insect larvae, rotated to keep them interested.
• Tiny crustaceans such as daphnia or live baby brine shrimp for variety and conditioning.

Behavior and Tank Setup

These fish are curious, bold, and opinionated. They can be nippy and territorial, especially males, so the best setup is a tank packed with plants and hardscape that breaks lines of sight. Think of it as building a maze, not a stage.

A species focused tank is often the easiest path to success. If you do try tank mates, pick calm fish that do not have long fins and that will not outcompete them at feeding time. Most problems start at the dinner table.

Gentle filtration is important, but so is oxygenation. Sponge filters and plant heavy tanks pair well, and they keep fry safe if you end up with surprise babies.

Breeding

Breeding pea puffers is very doable, but the eggs and fry are tiny and the adults are not shy about snacks. If you want consistent results, treat breeding as a separate project, not something that happens by accident in a display tank.

Conditioning

Condition the group with rich foods, especially live foods, for one to two weeks. Females should become noticeably round with eggs and males often intensify in color and attitude.

Spawning setup

Provide dense fine cover such as a thick clump of java moss or very fine stem plants. Spawning often happens deep in vegetation. Eggs are adhesive and are usually hidden in plants.

Egg handling and hatch

Many breeders move the moss clump or eggs to a small rearing container with identical water and a seasoned sponge filter. At warmer temperatures, hatch is often reported around five days. Newly hatched fry usually remain quiet at first and live off yolk before they begin hunting.

Raising fry

The first week is the bottleneck. The fry need very small foods and they do best when the rearing container is full of micro life. A moss packed setup that has been running for a while often outperforms a sterile box.

First foods and growth progression

• Days 1 to 4 after hatch, yolk stage, keep water clean and avoid strong flow.
• When they begin hunting, offer infusoria and rotifers, plus micro worms or vinegar eels if available.
• After they size up, introduce live baby brine shrimp. Many keepers begin this around the end of the first week, depending on fry size.
• As they grow, add finely chopped frozen foods and tiny snails.

Water and survival tips

• Use a seasoned sponge filter and keep aeration gentle.
• Perform small frequent water changes, such as 10 to 20 percent daily or every other day, matching temperature closely.
• Provide heavy cover, because size differences can lead to bullying and cannibalism.

Breeder’s Tips

• Trigger spawning with heavy live foods and a calm, plant packed tank
• Use a thick moss clump as the spawning mop, the eggs disappear into it
• Move the moss or eggs to a separate rearing container so the adults do not eat them
• Seed the rearing container with micro life, then start with infusoria and rotifers, and move up to baby brine shrimp
• Do small frequent water changes, match temperature, keep flow gentle, and keep the tank stuffed with cover

Quick Facts

• Adult size
  Up to about 1.4 inches, 3.5 cm total length
• Tank size
  Ten gallons can work for a single fish, but a planted twenty gallon is often easier for a small group
• Temperature
  74 to 82 F, 23 to 28 C
• pH
  Often kept around neutral to moderately alkaline, roughly 7.2 to 8.3
• Water type
  Freshwater
• Diet
  Micro predator, best with snails plus live or frozen meaty foods
• Temperament
  Territorial, can be nippy, provide heavy cover
• Plants
  Heavily planted tanks reduce stress and improve success
• Breeding note
  Eggs hidden in vegetation, fry need micro foods first
• Conservation
  IUCN listed as Vulnerable

Tropical Fish Co. Notes

A pea puffer is basically a tiny water puppy with the soul of a serious hunter. If you give them a plant jungle, a few snails to stalk, and a routine at feeding time, they repay you with nonstop personality.

We do not recommend chasing parameters unless you are targeting a specific breeding goal. Stable, clean water and a low stress layout matter more than a perfect number on a test kit.

Whenever possible, choose tank bred specimens. Wild populations have faced heavy collection pressure and habitat loss, and this species is listed as Vulnerable.