Black Ruby Barb (Pethia nigrofasciata) Breeding Guide

Breeding Pethia nigrofasciata: sexing by the male's spawning colour, conditioning, an egg-trap spawning tank, and rearing the 100+ eggs that hatch in 1-2 days.

Overview

Pethia nigrofasciata is a barb endemic to Sri Lanka, restricted to forest streams of the Kelani and Nilwala basins in the island's southwestern wet zone. It reaches about 50-55 mm standard length and is an egg-scattering spawner with no parental care that has been bred successfully in captivity.

Sexing

Adult males are noticeably smaller, slimmer and more colourful than females, especially during the spawning season, when the colour pattern darkens and the head and front of the body become reddish-purple. Females are plainer and rounder-bellied.

Conditioning

Condition adults together on a varied diet until males show their nuptial colour and females are full of roe. Wild-type fish do best in soft, slightly acidic water; farm-raised stock is more adaptable.

Breeding Setup

Place a well-conditioned pair in a very dimly lit spawning tank with a mesh or plant base so eggs can fall through while the adults cannot reach them. FishBase notes spawning occurs in shallow water among marginal weeds, so fine-leaved plants suit this species well.

Spawning Behavior & Trigger

The pair scatters eggs over the spawning medium; clutches can exceed 100 eggs. Warm, soft water and good conditioning bring the fish into spawning condition.

Egg & Fry Care

The adults will probably eat the eggs given the chance and should be removed as soon as any are noticed. Eggs hatch in roughly 1-2 days, with fry free-swimming around 24 hours later. Start the fry on infusoria-grade food until they can accept microworm or Artemia nauplii.

Common Challenges

Egg predation is the main risk and is solved by an egg-trap base and prompt removal of adults. Wild-collected stock may be reluctant to spawn unless the soft, acidic water of its native streams is provided.