Spider Crab (Macroregonia macrochira)
Spider Crabs are major predators and scavengers at Axial Seamount. They belong to Order Decapoda, and therefore have four pairs of walking legs, and a set of large claws. Spider Crabs use these claws to move food found on the seafloor to their mouths. They are slow moving, but migrate over the lava flow seafloor with ease, being attracted to any unusual disturbances, such as the construction of a deep sea observatory!
These large arthropods are noted for their affinity for and curiosity about instruments being placed on the seafloor. They have been known to act aggressively to submersibles and robotic vehicles. Spider Crabs are very common on Axial Seamount. Females and juveniles are found closer to the vent fields, while the males range further afield. Adults can have a leg span of up to 80 cm (31.5 in).
http://www.nrcresearchpress.com/doi/abs/10.1139/z87-369#.U9Q519hOX3g http://www.pmel.noaa.gov/eoi/nemo/explorer/bio_gallery/biogallery-Info.00016.html http://www.pmel.noaa.gov/eoi/nemo/explorer/bio_gallery/biogallery-Info.00017.html