Cryptic (phantom) merles are merles that have no visible blue or light red, yet they can produce merles when bred to nonmerles. They can also produce homozygous merles if bred to a merle. This can be quite a surprise to the breeder, when two seemingly black tris produce a litter that contains merles as well. The lack of visible blue could be because it is just very reduced in amount so that it is inconspicuous, or it could be that whatever blue there would have been has been concealed by a white marking. Sometimes only a pup's tail is blue, so when it is docked there goes the blue! True cryptics are very rare, but their existence is documented. I have seen only a couple of examples of true cryptic merles, one of which is the puppy at the bottom of the page. But all these dogs are good examples of reduction of merling to the point of approaching cryptic status. At the Texas A&M Vet School a genetic test has been created which will tell a breeder whether the dog has 1, 2, or zero copies of the merle gene. It no longer has to come as a breeding surprise.
This is Bruce, photo courtesy of Heike Poole of Germany. Bruce is a minimal blue merle. The only merling on his whole body is that little patch of blue on his elbow. He is not a cryptic merle, since his merle status can clearly be seen and identified. He also has the EMmask displacing the tan points on his muzzle (see the section on markings).
Netop Blown Away is also a very reduced merle, approaching cryptic status. The only merle she has is right here on the left side of her face. If the merled area had been on her neck, her white collar would have obscured it from our view. No one would have known she was a merle at all without a DNA test or her producing a merle puppy with a solid.
Miette is an example of the same type of reduced merling in a blue merle. Because there is more color contrast than in the red merle you can see the blue very clearly. But it is limited to her face; with a good roll in the mud she might pass for a self black.
Gibson is a very handsome blue merle with the least merling of all the examples on this page. It is limited to a tiny area on the edge of his ear. It is not unusual for nonmerle dogs to have a small white marking here, so compare the color of the area to a piece of typing paper to help determine whether it is a blue area or merely a white spot.
Here, finally, is a true cryptic merle! This puppy looks like a normal black tri, but his tail is blue! The only blue on his whole body is that tail. Once docked, visible blue is gone, and he looks like a regular black tri. But genetically he is a blue merle and should be registered as such. Areas on his sides that may appear bluish are just highlights from the flash. This pup has an aunt who also was born with a blue tail. Perhaps the tendency toward reduced merling is inherited, since the reverse has been found to be true in collies. If this boy were bred to another merle, homozygous merles could be expected, despite his very dark coloring. It is also possible that he might sire other reduced or crypic merles if it turns out there is a genetic component.
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