Posted by: mystery_man on July 10th, 2010
Phantom Giant Rays
The Nagara River of Gifu prefecture, Japan, has been the source of several sightings of what appear to be giant, river going rays.
The first report surfaced in 1986 in Hashima City, Gifu, where an eyewitness described seeing a ray-like fish with “wings.” The mysterious fish was estimated as being 2 meters (6.6 feet) long and 1 meter (3.2 feet) wide from wingtip to wingtip. It was said to appear to be “flying” through the water. Although only the silhouette of the creature was seen, the witness, a long time resident of the area, said the shape of the creature was very much like that of a ray and unlike anything he had ever seen in the river before.
A few other sightings of the mysterious fish have popped up over the years, all describing the same distinctive “winged” shape of the original sighting.
This strange creature could be a ray that has travelled inland from the sea, although this would be very unusual for a saltwater fish of this type to do. There are freshwater rays however Japan has no known native species like this.
Nevertheless some of the largest rays in the world are freshwater species. The Mekong River giant freshwater stingray of Southeast Asia can be 5 meters (16.4 feet) long and up to a whopping 600 kg (1,300 lbs). Could there be some similar type of large, freshwater ray remaining undiscovered in Japan?
Another possibility is that perhaps a Pacific halibut (Hippoglossus stendepis) somehow made its way inland from the sea. The shape of a halibut could certainly be seen as being somewhat ray-like, and these fish are known in Japanese waters. They can also get huge, with some specimens reported as being over 8 feet long and over 700 lbs.
The problem with this hypothesis is that halibut are not known to venture into freshwater, and would probably not survive long if they did. In addition, the older, larger individuals prefer deep water where they would be more unlikely to find their way into a river to begin with.
There are only a small handful of sightings of this enigmatic river creature, so it seems likely we may never know for sure.