Gandalfus yunohana

Gandalfus yunohana is a species of crab found on hydrothermal vents on the eastern edge of the Philippine Sea Plate south of Japan. It lives at shallower depths than other members of the family Bythograeidae, at 420–1,380 m (1,380–4,530 ft). Because no light penetrates to such depths, the eyes of G. yunohana are immobile and unpigmented. Males have a carapace up to 41.9 mm × 26.9 mm (1.6 in × 1.1 in) across, while females are larger, at 50.5 mm × 32.5 mm (2.0 in × 1.3 in). It was originally described as Austinograea yunohana in 2000, but was transferred in 2007 by Colin McLay to his new genus, Gandalfus, named after the character Gandalf from The Lord of the Rings.