Oranda Goldfish Breeding Guide

How to breed the Oranda goldfish (Carassius auratus var. Oranda): spring spawning trigger, egg scattering on plants, ~4-day hatch and selective breeding for the wen.

Overview

The Oranda is a selectively bred variety of the goldfish, Carassius auratus, distinguished by a prominent head growth called a wen. It breeds with the same egg-scattering biology as other goldfish; the challenge with fancy varieties is producing offspring that develop the desired body shape and wen. The headgrowth of young fry may take one to two years to develop.

Sexing

Mature goldfish are sexed most reliably in the breeding season, when males develop small white breeding tubercles (stars) on the gill covers and leading pectoral-fin rays. Gravid females become noticeably rounder and deeper-bodied as they fill with eggs. Tubercles are typically present from spring through autumn.

Conditioning

A breeding programme normally starts in early spring with the water warmed to about 17 degrees C (63 degrees F), and fish should be well reconditioned after the cooler winter period. Breeders often spawn one female with two or three males to improve fertilization. Plenty of fine-leaved spawning medium, such as hornwort or a spawning mop, should be added.

Spawning Behavior & Trigger

Spawning is triggered by a significant temperature rise in spring, as the water approaches about 20 degrees C (68 degrees F). Males chase the gravid female and prompt her to release eggs by bumping and nudging her. The adhesive eggs scatter and stick to plants such as Cabomba, Elodea or a spawning mop.

Egg & Fry Care

Because adult goldfish readily eat their own eggs, the parents should be removed as soon as spawning is over (the eggs are adhesive and cannot easily be moved). The eggs hatch in about four days, and the fry become free-swimming roughly 24 hours later, which is when feeding begins. Fry are an undistinguished metallic brown and may take a year before developing mature goldfish coloration.

Common Challenges

Most fry will not show ideal Oranda traits, so breeders cull heavily, selecting only those developing a good body shape, finnage and an evenly forming wen. Some highly selectively bred goldfish can no longer breed naturally due to their altered shape, but the Oranda generally remains capable of natural spawning.