Japan's fishing industry is up in arms as giant jellyfish lessens their daily catch.

"It's a terrible problem. They're like aliens," Noriyuki Kani of the fisheries federation in Toyama, northwest of Tokyo, tells Reuters.

"If your nets are full of jellyfish, of course there is no space for fish."

One Echizen kurage can be up to 6 feet, 7 inches in diameter and weigh up to 440 pounds.

Much about the jellyfish, the largest variety found in the Sea of Japan, remains a mystery, according to Hitoshi Iizumi of the Seikai National Fisheries Research Institute in Niigata, in a CNN report.