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Tortoiseshell
A mottled blend of a black-series colour and red, seen almost only in females.
EMS code: fGroup: Tortie / Calico
The genetics
Tortoiseshell arises from X-chromosome inactivation: a female carrying both a black-series colour and red expresses each in patches. It is almost exclusively female.
Cats in this colour
No cats in this colour yet.
Frequently asked questions
Why are almost all tortoiseshell cats female?+
The red gene sits on the X chromosome, so showing both red and a black-series colour together normally needs two X chromosomes — i.e. a female.
Related colours
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