Benizuwaigani crabs, a type of snow crab, cluster around sea floor methane vents, researchers at the University of Tokyo said. The research was conducted in an area 30 to 40 kilometers off the coast of Naoetsu, Niigata Prefecture, at a depth of 900 to 1,000 meters from sea level. The area is known as a fishing ground for the crab, as well as an area containing deposits of methane hydrate, a possible next-generation fuel that has a sherbet-like consistency.