Many people believe the Tortoiseshell cat is a breed of cat, however, that is simply not true. The name refers to a colour pattern found in many breeds that occurs due to genetic reasons.
The pattern consists of two colours, but sometimes the occasional spot of white fur also occurs. The most common colours are black and orange, but different variations of those two colours aren't unusual.
The colours of a Tortoiseshell cat
Black and orange are the standard colours, but variatons of those two are still recognised as Tortoiseshell cat colours. Variations of the black colour can instead be blue, grey, chocolate or even tabby. The other variations to red can be cream, orange or even yellow.
The pattern itself is asymmetrical and varies from cat to cat.
The chromosomes of a Tortoiseshell cat
A Tortoiseshell cat is almost always