Unlike the dominant Manx gene, the Bobtail gene is not associated with skeletal disorders. Species include recognizable fish such as pelican eels, bobtail eels, and gulper eels. In the Japanese Bobtail, odd-eyed cats are most frequently found in calico individuals. The American Bobtail is hearty, short-tailed cat. The luminescent bacterium is often "Aliivibrio fischeri", as for example in the Hawaiian bobtail squid. The tail can be natural, bobtail, or docked. Most use a two or 3 letter acronym e.g. MK (Munchkin), JBT (Japanese Bobtail). The bobtail is essentially the front of a tractor-trailer combo. The Mekong Bobtail (formerly known as the Thai Bobtail) is a breed of cat. At least 170 dog breeds have naturally occurring bobtail lines. Dogs born with short or natural bobtail will be indicated on the FCI pedigree. It is claimed that a wild cat, the Kurilian Bobtail, originates from the Kuril Islands. The bobtail is due to the mutation of a dominant gene. The most common coat colors are in red, to grey, to bobtail stripes. Approximately 30% of individuals have a natural bobtail.