But there are some "really surprising deviations from that behavior," he explains—"like instead of diving down to 1,500 feet, a swordfish goes to 3,000 or 6,000 feet, much deeper than we would ...

A sea fan near the Pacific atoll of Ulithi, at a depth of 3,600 feet (1.1 km). Findings from video of this dive and those of James Cameron's Challenger Deep expedition and of one to New Britain ...