Researchers spotted an albino killer whale off the shores of Russia on Sunday, the first time anyone has documented an adult white killer whale. Whale watchers have seen white calves in the past, but none have been known to grow to adulthood, researchers said.

Researchers hope to collect a genetic sample from the whale, named Iceberg, to determine the origin of its albinism, research leader Erich Hoyt, a senior research fellow with the Whale and Dolphin Conservation society, said in a blog post.

We have no genetic data [on the whale] but we are hoping to meet them again in summer 2012 and learn more about the phenomenon of white whales, why they occur, what it means and whether Iceberg is a true albino - perhaps we can catch a glimpse of a pink eye - or 'just' one of the most beautiful orcas anyone has ever seen, Hoyt wrote.

Albinism is a congenital disorder characterized by a lack of pigment in the skin. Albino people and animals appear white or very pale and often have pink eyes. Albino humans frequently have vision problems and are at a greater risk of sunburn and skin cancer. Albino animals are usually unable to hide from predators or prey, so their survival rate in the wild is typically low.

Click through the slideshow for some examples of albino animals.