The African clawed frogs have undergone drastic changes in chromosome number during their evolution, making them some of the most genetically unusual creatures in the world. They exhibit polyploidy, meaning they have more than the two sets of chromosomes found in most other organisms (known as diploid). The Lake Oku clawed frog has 12 sets of chromosomes, so is dodecaploid. The only known habitat is Lake Oku, a freshwater lake completely surrounded by montane rainforest found 2,219 metres above sea level on Mount Oku, the second highest peak in mainland West Africa. Local people respect this lake as a sacred place and no fish have been introduced. Invasive predators could prove catastrophic to the clawed frog population.