Pea Puffer Breeding Guide

Breeding Carinotetraodon travancoricus: sexing, harem setup in dense moss, daily small spawns, and rearing the tiny carnivorous fry.

Overview

Carinotetraodon travancoricus is among the smallest pufferfishes in the world, with a maximum documented size of 3.5 cm total length; most individuals stay under 2.5 cm. It is one of the few fully freshwater puffers and spawns among dense vegetation. Peak spawning in the wild runs from May to August, and sexual maturity in the Pamba River population occurs at roughly 1.83 cm.

Sexing

Males show a clear dark line running lengthways along much of the belly and a pattern of closely arranged lines just behind the eye, along with iridescent blue eye-wrinkle markings. Sexually mature females are noticeably rounder-bodied than males. Juveniles are difficult to sex.

Breeding Setup

Because males can fight fatally, spawn in pairs or as a harem of a single male with multiple females. The spawning tank need not be large and can use gentle air-powered filtration. Dense planting is essential, ideally with fine-leaved plants such as Cabomba, Ambulia and Java or Willow Moss, which are the preferred spawning medium. Maintain a temperature toward 22-28 C and pH around 6.8-8.0, conditioning the fish on meaty frozen foods and small snails.

Spawning Behavior & Trigger

Courtship involves the male pursuing the female vigorously, often biting and nipping, with spawning occurring in low vegetation and simultaneous release of eggs and milt. The fish often spawn on a daily basis, and the tiny non-adhesive eggs (around 1 mm) usually yield ten or fewer per event. Eggs should be removed to a controlled rearing container.

Egg & Fry Care

Eggs hatch in around 5 days, with a further 2-3 days for yolk absorption. First foods are very small motile invertebrates such as microworm, moving on to Artemia nauplii after the first week and to frozen bloodworm and larger items from about a month.

Common Challenges

Yields per spawn are small, and larger fry will prey on smaller siblings when raised together, so size grading helps. Male aggression toward other males makes a harem or pair arrangement safer than a multi-male group.