During the early 19th century, a distinct breed of tailless domestic cats emerged on the Isle of Man. Known for their rounded appearance, long hind legs, and complete or partial absence of a tail, these cats came to be known as Manx.
While the origin of their mutation is genetic, not mythical, the story of the Manx cat has traveled across centuries, borders, and scientific disciplines, tracing a path from island farms to genetic research labs.
The Manx cat’s defining feature is a dominant mutation affecting the spine, resulting in various tail lengths, from none at all to a full tail. By the 1800s, tailless cats referred to locally as “stubbin” or “rumpy” were a common sight on the Isle of Man.
Folklore stories claimed the trait arrived with shipwreck survivors or was the result of humorous accidents, but genetic studies later confirmed a natural mutation, reinforced by the isolated breeding population on the island.
In 1903, a breed standard for the Manx was published by Charles Henry Lane, and show records date back to the late 1800s. The Cat Fanciers’ Association in the U.S. included the breed early in its registry.
While often praised for their hunting ability and sociable nature, Manx cats were also known aboard ships, where their rodent control skills were valued. Variants of the breed developed, including the long-haired Cymric and the tailed Isle of Man Shorthair, each with its own registry status.
Genetic studies have revealed that the taillessness is caused by a mutation in the brachyury gene. However, breeding two tailless Manx cats can be fatal for the offspring due to spinal deformities. In response, controlled breeding practices and international regulations were introduced.
In 2015, a project called the Manx Cat Genome Project was launched in the Isle of Man to sequence the genome of the breed. The first cat sequenced, a rumpy calico named Bonnag, had her tail mutation identified as a single-bit deletion in her DNA.
Beyond science, the Manx cat is featured in Isle of Man currency, stamps, tourist items, and literature. From local folklore to genome sequencing, the breed’s path has been shaped by observation, classification, and ongoing study. With its presence stretching from village shops to scientific databases, the Manx cat remains one of the world’s most distinct and studied domestic felines.
On a rugged island in the Irish Sea, a cat without a tail became a subject of fascination.
The Manx cat, with its unique spinal mutation, captured attention not only for its look but also for its roots in folklore, cat shows, genetic studies, and currency…🧵👇 pic.twitter.com/q8nHAf3gZf
— Detective Tiger's Stories (@TigerDetective) June 21, 2025