The newly discovered deep-sea hydrothermal vent field “Loki’s Castle” at 2,350 m depth at 70°N on the Knipovich Ridge north of the island Jan Mayen is the only known black smoker field from the Arctic Ridge system. This vent field holds a unique fauna clearly distinct from vent sites along the Mid-Atlantic Ridge south of Iceland. In addition to numerous maldanid and ampharetid polychaetes one animal ...