A rare megamouth shark swims in a fish pen after being moved from a fixed net where it was trapped in May 2017. The video also shows the enormous full-body skeleton of the shark on a permanent display at Kamogawa Seaworld, Kamogawa, Chiba Prefecture, which started on Dec. 7. (Video by Kotaro Ebara)

KAMOGAWA, Chiba Prefecture--A full-body skeleton of an ultra-rare megamouth shark is now on show at an aquarium here, the world’s first such assembly and display.

The stunning skeleton of the megamouth shark, also called a massive phantom shark, went on permanent display at Kamogawa Seaworld starting Dec. 7.

“Using its skeleton, we recreated a scene of a megamouth shark preying on plankton,” said Kazuhiro Nakaya, 73, a professor emeritus of fisheries science at Hokkaido University, who supervised the making of the skeletal preparations of the shark.

With only 135 cases of the megamouth shark being caught in the world, including 23 catches in Japan, the elusive shark has been cloaked in mystery.

The skeleton belongs to a female shark, the 22nd discovery of a megamouth shark in the country. The shark, weighing around 1.2 tons and around 5.4 meters long, was trapped in a set net off Tateyama, Chiba Prefecture, in May last year.

Under Nakaya’s supervision, the skeleton was assembled by Kyoto-based Yoshida Biological Laboratory, which boasts a solid reputation for its techniques to preserve cultural properties.

The successful assembly and preservation of the complete skeleton was largely attributed to a special treatment by replacing moisture in the skeleton with solidified alcohol.

Since the skeleton is cartilage containing an extensive amount of moisture, it would shrink if it were dried as is without any treatment.