Also often known as the calico cat in the United States, tortoiseshell refers to the pattern and coloration of the coats of cats and not to any specific breed. The majority of tortoiseshell, or torties, are females because the gene that is responsible for the coat patterns is on the X chromosome.
When a male cat is born a tortoiseshell he will more often than not be sterile. This is because there is an imbalance in his chromosomes that has resulted in him having an extra X chromosome. Breeders often reject these XXY cats because they are unlikely to win at cat shows.
The tortoiseshell cat’s coat will be mottled with several patches of blacks, browns, and oranges. They will often have little to no white on their fur but some may have white on their face, their bellies, or their legs. Tortoiseshell markings can appear in just about every breed, with the exception of the breeds that are thought to be Oriental cat breeds.
Dilute tortoiseshell refers to when the coloration of the cat’s coats are much softer colors versus the bright oranges and dark browns or blacks. The colors tend to be softer and almost faded when compared to a regular tortoiseshell coat.
Dilute tortoiseshell cats can be both longhaired and shorthaired, and may even be Maine Coon cats. Maine Coons are well known for their exceptionally long hair.
Because the dilute tortoiseshell markings can appear in just about every domestic cat breed, there are unlikely to be any characteristic unique to dilute tortoiseshells. However, owners of tortoiseshells tend to claim that their cats have much more in the way of an independent and stubborn nature.