Case No. #1479
The Giant Cephalopod of the Goto Islands Waters
Summary
Between 2021 and 2022, fishermen and recreational divers near the Goto Islands in the East China Sea off Nagasaki reported a series of encounters with a massive cephalopod-like creature estimated at 6 to 10 meters in length. Fish-finders recorded anomalous large-object returns in the area on multiple occasions. In January 2022, a trawler recovered a 1.2-meter tissue fragment with 40-centimeter sucker scars. Genetic analysis found sequences related to giant squid but not matching any catalogued species precisely.
Details
The Goto Islands in the East China Sea off Nagasaki Prefecture are situated above some of Japan's richest fishing grounds. Giant squid are known to inhabit surrounding deep waters and have been documented in the region on prior occasions. The creature now under investigation appears to exceed even the largest recorded giant squid specimens (total length up to 13 meters, mantle length 3–4 meters) in size, and the Bureau is considering the possibility of an undescribed species.
In April 2021, a fisherman working grounds north of the islands recorded an anomalous large return on his fish-finder at 150–200 meters depth. The return's dimensions were comparable to a large fish of 3–4 meters, but the shape characteristics and movement pattern were inconsistent with any known fish species in the area. Similar returns were subsequently reported by multiple fishermen working the same grounds.
In August 2021, a group of recreational divers at 30 meters depth south of Fukue Island reported that "a massive object crossed the field of view from below." The diver who filed the report estimated the object's length at more than six meters, though limited visibility prevented detailed observation. The following month, a fishing net was recovered from nearby waters in a state of destruction consistent with having been pulled downward by an external force.
In January 2022, the most concrete physical evidence emerged. A trawler working grounds near Mikata recovered a rubbery tissue fragment measuring 1.2 meters in length, with a row of circular sucker scars approximately 40 centimeters in diameter. The morphology suggested a cephalopod tentacle segment. A specialist institution analyzed the recovered tissue and found genetic sequences closely related to giant squid but not precisely matching any entry in the known-species database.
The analysis team cautioned that degradation during preservation or sample processing could account for database mismatches. A definitive conclusion was not reached. The Bureau is pursuing additional sample collection and considering deployment of a deep-sea observation platform.
Timeline
- April 2021Fisherman north of the Goto Islands records anomalous large irregular fish-finder return at 150–200 m depth.
- August 2021Recreational diver south of Fukue Island observes a 6-meter-plus silhouette passing below at 30 m depth.
- September 2021Fishing net recovered from the area showing structural damage consistent with downward force.
- January 2022Trawler recovers 1.2-meter tissue fragment with 40-cm sucker scars. Submitted for specialist analysis.
- Spring 2022Genetic analysis finds sequences related to but not matching any catalogued giant squid species. No definitive conclusion.
- PresentAdditional sample collection ongoing. Deep-sea observation equipment deployment under consideration.
Witness Testimony
Fisherman (male, 50s)"I've never seen a fish-finder return like that. Not the shape of a fish. One mass, moving erratically. The size was wrong. Squid or octopus — nothing that size exists in these waters as far as I know."
Recreational diver (male, 30s)"Suddenly a huge silhouette crossed below me. Four times my height at least. Tentacles extended. I went up immediately. The guide told me later that strange things are sometimes seen in that area."
Fishery cooperative member (female, 40s)"The net couldn't be hauled in, and when I let go of the line it came back up. Something rubbery was tangled in it. Circular marks, like sucker prints, lined up one after another. About forty centimeters across. No one believed me, but it happened."
Kyu's Analysis
The genetic sequence does not match any catalogued species. The sucker diameter is forty centimeters. The possibility of an undescribed species cannot be excluded.
