Marine scientists have hoisted up a mysterious new species of "supergiant" amphipods from one of the deepest ocean trenches in the world, National Geographic reported last Thursday.

Seven of the pinkish, shrimp-like animals crawled into a trap left in the Kermadec Trench, an abysmal rift in the seafloor off the northern coast of New Zealand that sinks down 10 kilometers.

The largest amphipod measured in at least 28 centimeters—nearly three times larger than the previous record-holder—and was captured at a depth of about 7,000 meters. It's not yet clear whether the newfound giants represent a new species or just especially big supergiant amphipods.

Alan Jamieson, a marine biologist at the University of Aberdeen and co-leader of the expedition, was hoping to find a species of snailfish that had eluded scientists' capture for half a century—but was shocked by the giant, shrimp-like amphipod instead.

"Amphipods are common to deep-sea trenches, but they're usually 2 to 3 centimeters [about an inch] long. They turn up in a matter of minutes like a swarm of bees and simply devour all of the bait," Jamieson said.

"Now all of the sudden we have this monster amphipod and no other known sizes in between."