NIIGATA - A number of giant squids have been caught along the coast of the Sea of Japan this year, raising concerns among fishermen that it might represent some kind of “omen.”
The giant squid, classified as Architeuthis, is the largest invertebrate.
One giant squid was taken to Himi fishing port in Toyama Prefecture on Jan. 4. Another was found in a stationary net off Sado Island in Niigata Prefecture on Jan. 8.
Arms and tentacles believed to be from a giant squid were found washed ashore in Kashiwazaki, Niigata Prefecture, on Jan. 19.
Two days later, a monster squid was caught in a net off the town of Iwami, Tottori Prefecture.
In addition, another giant squid was caught in a net off Sado again and taken there Feb. 11.
The three squids taken to Sado and Himi measured 3 to 4 meters long. The one caught in Tottori was missing its two longest tentacles, meaning the creature could have been around 8 meters long before it was captured.
Shigenori Goto, a 44-year-old fisherman, caught the two squids off Sado.
“I had seen no giant squid before in my 15-year fishing career,” he said. “I wonder whether it may be some kind of omen.”
Giant squids usually live about 600 meters below the water’s surface where temperatures are 6 to 10 degrees, said 62-year-old Tsunemi Kubodera, the collection director at the National Museum of Nature and Science.
While they prefer warm waters, such as those off the Ogasawara Islands, they occasionally stray into the Sea of Japan for some reason via the Tsushima Strait lying between Japan and the Korean Peninsula, Kubodera said.
More than 300 meters below the surface in the Sea of Japan, there is a layer of cold water of zero to 1 degree, but giant squids can survive at depths of around 200 meters.
Temperatures at 200 meters are usually around 7 degrees in January. But they fell to about 4 degrees this year, according to the Meteorological Agency.
Kubodera speculates that giant squids swam close to the surface in pursuit of warm water but were unable to stay buoyant and got swept toward the beach by winds.
A 14-meter-long giant squid caught off the Bahamas in the Atlantic in 1966 is the largest ever confirmed.
The life cycle of giant squids, such as spawning sites and life span, remains largely unknown.
Although a diver photographed a baby giant squid, about 2 cm long, off Nishiizu, Shizuoka Prefecture, for the first time ever in 2002, no eggs have ever been discovered.
Some of the giant squids caught this year have been frozen for study. “We’ll use all clues to find out the deep-sea life cycle” of giant squids, which are precious creatures whose populations are small, Kubodera said.