Populations of tailless cats also exist in a few other places in Europe, most notably Cornwall, only from the Isle of Man. A population on the small, isolated Danish peninsula (former island) of Reersø in the Great Belt may be due to the arrival on the island of cats of Manx origin, by ship. Similar cats are also found in Crimea, a near-island peninsula in the Black Sea, though whether they are genetically related to maritime Manx cats or are a coincidentally similar result of insular genetic diversity limitations, like the unrelated Kuril Islands Bobtail, Karelian Bobtail, Japanese Bobtail, and Indonesian Lombok cats, is unknown. The Manx gene may be related to the similarly dominant tail suppression gene of the recent American Bobtail breed, but Manx, Japanese Bobtails and other short-tailed cats are not used in its breeding program, and the mutation seems to have appeared in the breed spontaneously. Possible relation to the Pixie-bob breed, which also ranges from rumpy to fully tailed, is unknown.