While we adapt to shorter, darker days with less sun and more snow, an ultra-rare sea creature well adapted to darkness was recently sighted again. In the deep sea—some 600 to 800 feet underwater, where sunlight dwindles to near pitch-black—there dwells a fish with unusual features well suited to that extreme environment. Several species of the Opisthoproctidae fish family are aptly dubbed “barreleyes,” because of their elongated, tube-shaped eyes that allow them to make their living in the ocean’s “twilight zone.” A recent sighting of this rare fish last December had researchers from Monterey Bay Aquarium Research Institute (MBARI) abuzz. “I spy with my barreleye, a new Fresh from the Deep!” researchers captioned on MBARI’s YouTube channel, where they posted footage of the encounter. The barreleye Macropinna microstoma is not a large fish, measuring only 15 centimeters (6 inches) long; nor are its black scales and large black fins that unusual. The strangeness …