Vast numbers of Echizen jellyfish have appeared on Japan's Pacific coast apparently after drifting from Chinese and Korean waters where they reproduce every year.
One Echizen jellyfish can be up to 7 feet in diameter and weigh up to 660 pounds.
The non-edible creature has the local fishing industry in the grip of its poisonous tentacles as the invertebrates clog fishing nets, poisoning and crushing the catch.
Some experts estimate that the outbreak of jellyfish has brought Japan's fishing industry financial losses amounting to at least $110 million.
One Japanese fishing boat in the Pacific capsized by the weight of the heavy jellyfish that got stuck in its fishing net.
Still, much about the jellyfish remains a mystery. Pollution in the waters off China is also believed to making it easier for jellyfish to breed. Japan's Meteorological Agency says the waters of the Sea of Japan - an area surrounded by Japan, China and South Korea - are warming at a speed three times faster than that of the global average.