Ringed seal have been on display at Kaiyukan since March 2013. On April 1, 2021, the first birth occurred at the aquarium. However, the newborn was found to be in poor health, including hypothermia, immediately after birth, so the pup was removed and treated. As the pup's condition did not stabilize after that, the decision was given up on returning it to its parents, and the aquarium keeper decided to raise it artificially, with the pup acting as a parent instead.

There are very few cases of Ringed seal breeding in captivity, and this was the first attempt at complete artificial rearing in Japan, so there was little reference material available, and problems arose during artificial rearing, such as the seals not being able to defecate or not gaining weight, but all the aquarium keeper in charge worked hard every day to find solutions, trying and failing to solve these problems. Thanks to this, the seals have grown to the point where they can be exhibited.

Special exhibition panel production

From August 1, 2021 to December 18, 2022, a aquarium keeper ' Arctic Region , and the white fur that fell out during its development.

Detailed growth record of Ringed seal for 100 days after birth