In the canaries of the black series the opal mutation transforms the black eumelanin into bluish gray. One of the lighter indications of the opal feather is that it is darker at the bottom, it is also very rigid, brittle and low elasticity in the black-bruno and agate samples, that is, in granules. of black eumelanin turned bluish grey, the concentration of eumelanin in the rachis.
When it comes to opal, a factor that mainly modifies the structure of feathers, the corneal parts of each type remain identical to those of their respective classical types.
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