He's known for travelling around the world on a sleigh pulled by reindeer on Christmas Eve, but children in Japan have been treated to the unusual sight of Santa and his trusty steed underwater.

At the Sunshine City Aquarium in Tokyo divers dressed up as Santa Claus and Rudolph the red-nosed reindeer to deliver presents to the sea creatures on 24 December.

Video footage of the event also shows Santa feeding a Manta Ray and hugging a shark, as visitors to the aquarium watched in awe. Ren Takahashi, a member of the divers' team, said it was the first time Rudolph had joined Santa in bringing the Christmas cheer underwater.

"In the past, it was always Santa diving alone. This year, we want to try both Rudolph and Santa diving together," she said.

Divers also led a school of fish to form a Christmas tree by ringing a special bell that attracted them underwater. A visitor who came with her daughter and husband said the fish-formed Christmas tree was the highlight of the show. "My daughter was very delighted when the fish gathered and formed the shape of a tree," said Nozomo Takahashi.

It wasn't just at the fish tanks that the aquarium got in the festive spirit, with visitors also delighted by a Christmas carol handbell ensemble played by a herd of seals.