Karyotypic variation in the Australian gekko Phyllodactylus marmoratus (Gray) (Gekkonidae: Reptilia).

The gekko Phyllodactylus marmoratus has at least three distinct chromosome races; 2n=39, 2n=26 ZZ/ZW and 2n=34. Specimens from these races are morphologically distinguishable, have a degree of habitat specialization and occur in a defined distribution. The 2n=36 race found in Eastern Australia is the presumed primordial type. The 2n=34 race occurs in Western Australia and is regarded as a fusion derivative. The 2n=36 ZZ/ZW race, which is only found on the Murray River system in Eastern Australia has a heteromorphic sex chromosome system present in the female. Giemsa banding suggests that this heteromorphism is the result of a pericentric inversion.