Bengal Danio (Devario devario) Breeding Guide

Breeding Devario devario: sexing, conditioning, a dimly lit mesh-bottom spawning tank, warm slightly acidic water, and rearing fry after a 24-36 hour incubation.

Overview

Devario devario is a tall-bodied South Asian danioin reaching about 70-80 mm in standard length. It is an egg-scattering free spawner with no parental care, and when in good condition it spawns often; in a well-planted, mature aquarium small numbers of fry may appear without intervention.

Sexing

Sexually mature females should be rounder-bellied, less colourful and a little larger than males. The distinction is clearest in well-conditioned adults.

Conditioning

Condition the adults together on a varied diet until females are visibly gravid, then select one or two pairs for the spawning tank.

Breeding Setup

Use a spawning tank with a base of at least 60 by 30 cm, kept very dimly lit. Cover the base with a mesh of a grade large enough for eggs to fall through but small enough that the adults cannot reach them. Keep the water slightly acidic to neutral with the temperature toward the upper end of the range (around 26 C), and add a sponge filter or air stone for aeration.

Spawning Behavior & Trigger

If the fish are ready, spawning usually takes place within 24 hours, with the female appearing noticeably slimmer afterwards. Eggs are scattered freely and fall through the mesh out of reach.

Egg & Fry Care

Remove the adults after spawning. Incubation lasts 24-36 hours with the fry free-swimming days later. Start the fry on Paramecium, then progress to Artemia nauplii and powdered foods as they grow.

Common Challenges

Egg loss to the parents and starvation of tiny first-feeding fry are the main hurdles. A mesh-bottom egg trap, prompt removal of adults, and a prepared supply of microscopic first foods address both.