Giant Nomura's Jellyfish Capsize Japanese Ship During Sex?

Most people have never heard of a Nomura's jellyfish, although they have probably seen examples of the giant invertebrates on television shows on Discovery or National Geographic or PBS. One of the largest jellyfish in the world, Nomura's jellyfish can grow to six feet in diameter and weigh as much as 450 pounds. Three crewmen on a Japanese fishing vessel trawling waters for a lucrative catch no doubt now wish they had never heard of the giant Nomura's jellyfish after their trawler was capsized by dozens of the massive animals caught in their nets.

According to The Telegraph, experts believe conditions in recent months have been relatively perfect for the Nomura's jellyfish to breed in the coastal waters of China, which might explain their presence in such high numbers. Some believe that the decrease in the natural predators of the Nomura's jellyfish may also provide preconditions for the giant sea creatures to appear. But little is known about the giant jellyfish, so such theories are mere speculation.

Monty Graham, a "jellyologist" at the Dauphin Island Sea Lab in Alabama, offered, ""Jellies have likely swum and swarmed in our seas for over 600 million years. When conditions are right, jelly swarms can form quickly. They appear to do this for sexual reproduction."

The three crewmen were tossed into the sea by their capsizing ship. Luckily, another nearby trawler, according to the Manichi Daily News, was there to haul them from water apparently teeming with giant sexually agitated jellyfish. The men were unharmed.

The last time a "swarm" occurred -- in 2005 -- the giant jellyfish damaged nets, caused fish to be inedible due to their toxic stings, and caused injuries to several fishermen. No one knows why the Nomura's jellyfish will suddenly appear by the thousands in one year but only be spotted sporadically the next. There were nearly no sightings of Nomura's jellyfish last year.

To add to the confusion of explaining why animals swarm, in 2007, a swarm of giant Humboldt squid appeared off the coast of southern California after an earthquake, beaching themselves. Scientists were unsure if the earthquake had actually caused the appearance, but admitted that the possibility existed that the squid had become disoriented by the earthquake.

A swarm of leopard sharks appeared off the Los Angeles beaches in the summer of 2008. Although they caused much consternation among beachgoers, experts assured that the sharks, which can grow to six feet in length, are not maneaters but prefer anchovies and shrimp. A similar swarm of thousands of sharks were spotted off the coast of Florida this past Spring. Experts maintained that they were migrating, feeding off baitfish.

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Sources:

Telegraph.co.uk
LiveScience.com
FearBeneath.com
Manichi.jp
SanDiego6.com
WSVN.com