The Jewel of the Aviary

In the vast and varied world of aviculture, few sights are as arresting as a clutch of brilliant blue eggs nestled in the straw. While the Ameraucana and Araucana chickens have long held the title for blue egg production, a quiet revolution has taken place in the quail world: the rise of the Celadon Coturnix. At Quailz.com, our Celadon hatching eggs are among our most sought-after products, but they are more than just a novelty—they are a biological marvel driven by a specific and rare genetic mutation. For the serious breeder or the backyard enthusiast, understanding the science behind the shell is key to successfully propagating this stunning trait.

The Biochemistry of Blue: Biliverdin vs. Protoporphyrin

To understand why a Celadon egg is blue, one must first understand why a standard quail egg is brown. The wild-type Coturnix quail egg is characterized by a base color overlaid with heavy speckling. This speckling is caused by protoporphyrin, a reddish-brown pigment derived from heme (blood). In a standard hen, this pigment is deposited onto the shell gland just before the egg is laid, creating the familiar camouflage pattern.

The Celadon mutation disrupts this process. It is a recessive mutation that inhibits the deposition of protoporphyrin. Instead, the shell is pigmented primarily by biliverdin and its zinc chelate, biliverdin-zinc. Biliverdin is a bile pigment produced from the breakdown of heme, and it is responsible for the blue-green coloration seen in eggshells (and, incidentally, in human bruises). In Celadon quail, the absence of the overwhelming brown pigment allows the delicate, teals and blues of the biliverdin to shine through.5 Because the pigment is deposited early in the shell formation process, the blue color often permeates the entire shell, meaning the inside of the shell is blue as well—a key indicator of a true blue egg gene.

The Genetics of Inheritance: The Recessive ce Gene

Breeding for Celadon is a lesson in Mendelian genetics. The trait is controlled by an autosomal recessive gene, denoted as ce.

• Homozygous Recessive (ce/ce): This bird carries two copies of the gene. A hen with this genotype will lay blue eggs. A rooster with this genotype will pass the blue gene to all his offspring.

• Heterozygous Carrier (Ce/ce): This bird carries one copy of the blue gene and one copy of the dominant wild-type gene. A hen with this genotype will lay standard speckled eggs, but she carries the potential to produce Celadon offspring if bred to a Celadon male.

• Homozygous Dominant (Ce/Ce): This bird does not carry the gene and will never produce blue egg-laying offspring unless bred to a carrier or Celadon, and even then, the first generation will only be carriers.

This recessive nature explains why the Celadon trait can seem to "disappear" or "reappear" in flocks. If you breed a Celadon hen to a non-Celadon rooster, none of the offspring will lay blue eggs in the first generation (F1), although all will be carriers. It is only by breeding these F1 carriers back to each other (or back to a Celadon parent) that the blue egg phenotype will re-emerge in the F2 generation.

Challenges in Celadon Breeding

One of the primary challenges with the Celadon line has historically been genetic diversity. Because the gene was originally isolated from a small population, early Celadon lines suffered from inbreeding depression, leading to smaller birds and lower hatch rates. However, at Quailz.com, we focus on outcrossing our Celadon carriers to our Jumbo lines. By carefully breeding Jumbo hens to Celadon roosters, and then selectively breeding the offspring, we are working to increase the size of the bird and the egg while retaining the beautiful blue shell color.20

The Celadon quail offers the best of both worlds: the production efficiency of the Coturnix and the aesthetic beauty of a rare ornamental. Whether you are looking to create a "rainbow carton" for your farmers market stand or simply want the thrill of finding a blue gem in the coop, our Celadon hatching eggs are the starting point for your genetic journey.