A tiny species of fish can claim some of the most unenviable of all records. The so-called Devils hole pupfish survives within one of the driest places in the world, in the heart of the Mojave desert in the US. Perhaps fewer than 50 individuals survive.
Even more remarkably, every member of this species has existed in the wild within an area no bigger than the living room in your house. Which makes the Devils hole pupfish perhaps the rarest of all fish, the world's loneliest species, and the most isolated animal species on Earth.