Marine biologists have observed an Arctic bobtail squid in its natural habitat for the first time, marking a rare discovery that shows the species can survive and reproduce in one of Earth's most extreme marine environments. According to the researchers, Northeast Greenland National Park is one of the largest national parks in the world, but remains one of the least-studied regions of the Arctic. The discovery was made at a depth of more than 164 feet in water measuring about 29 degrees Fahrenheit. The observation provides the first direct evidence that cephalopods, including squids and octopuses, can reproduce in sub-zero Arctic waters. Scientists said the discovery provides a valuable baseline for tracking ecological change in the rapidly warming Arctic.