Calico and Tortoiseshell cats do not belong to a specific cat breed, but are differentiated due to their peculiar color pattern. There are several cat breeds with the specific color pattern, as of Calico and Tortoiseshell cats. For a cat to be categorized under Calico cats, it should have three primary colors - white, black and orange. In case of Calico cats, the coat color is brindled with patches of red color and black or chocolate color. Hence, the only difference between Calico and Tortoiseshell cats is that in the latter case, there is little or no white patches. The genetic factor, responsible for their coloration is the same.
Facts About Calico Cats (Tortoiseshell Cats)
One of the most interesting facts about Calico and/or Tortoiseshell cats is that majority of them are females. Comparatively, male Calico cats are very rare. It is because of the fact that the coat color of a cat is determined by their genetic content. To be more precise, the color of the coat is a sex-linked trait.
Like most of the highly developed animals, the female Calico cats have two 'X' chromosomes (represented as XX), whereas the males have a single 'X' and a single 'Y' chromosomes (represented as XY). The X chromosome is responsible for both the black and orange coat color. The white color is coded by another gene.
In female cats, due to the presence of XX chromosomes, the two coat colors - black and orange, along with white and their variants are expressed. Whereas, in case of male cats, the single X chromosome either codes for black color or orange color coat. Thus, Calico and/or Tortoiseshell color combination occurs mostly in female cats, rather than male cats.
Male cats, with genetic aberration having XXY chromosomes can express Calico and/or Tortoiseshell color combination. Over here, like in females, the two X chromosomes express the three colors, responsible for the Calico color coat. Thus, male cats have Calico color combination very rarely. However, due to abnormal chromosomal configuration, male Calico or Tortoiseshell cats are sterile. This sex chromosome disorder in cats is similar to Klinefelter's syndrome or XXY Syndrome in humans.
Unlike the usual Calico coat combination (white, black and orange), if the coat color of a cat has patches of white, blue and cream, then the cat is known as muted Calico.
Calico and Tortoiseshell cats, due to their independent and quirky nature, make wonderful pets and are fun to be around. If proper training is provided in the kitten stage, they make good companions. As per the folklore of some cultures, Calico and Tortoiseshell cats are believed to bring luck to the owner. The Japanese sailors often carry Calico cats in their voyage, believing that the cats will protect them while at sea. Hence, for these reasons and their striking color pattern, many cat lovers have them as their pets. In the United States, cats with such color combination are referred to as 'money cats'.