2025.06.18

Living creature information

[They are growing rapidly] Three Southern rockhopper penguin chicks born

You can see the raising of the chicks in the exhibition tank . On May 29th (Thursday), June 7th (Saturday), and June 9th (Monday), 2025, three Southern rockhopper penguin chicks were born in the "Falkland Islands(Malvinas)" tank . The Southern rockhopper penguin kept in the "Falkland Islands(Malvinas)" tank entered their breeding season in late April, and three pairs were formed, one chick each, for a total of three chicks. Currently, the parents are raising the chicks in their own nests, and you can see them occasionally feeding the chicks by mouth. The chicks born earlier are also growing well, with the chick born on May 29th weighing over 1kg and the chick born on June 7th weighing over 500g. aquarium keeper are watching over the raising of the chicks, checking their health by weighing and observing them every morning. A parent and child of the Southern rockhopper penguin(photographed on June 11th) [About the Southern rockhopper penguin chicks] [1st chick] Hatching date: Thursday, May 29th, 2025 Gender: Unknown Weight: 75.3g (immediately after hatching) 1.1kg (as of June 18th) [2nd chick] Hatching date: Saturday, June 7th, 2025 Gender: Unknown Weight: 64.1g (immediately after hatching) 556.2g (as of June 18th) [3rd chick] Hatching date: Monday, June 9th, 2025 Gender: Unknown Weight: 49.7g (immediately after hatching) 235.8g (as of June 18th)

2025.06.13

Living creature information

California sea lion baby born

On Thursday, June 12, 2025, a baby California sea lion was born in the "Monterey Bay" tank . This is the 19th birth of a California sea lion at Kaiyukan . From Wednesday, June 11, 2025, the female "Asuka (15 years old)" living in the "Monterey Bay" tank was found to be showing signs of giving birth, and the aquarium keeper were observing her 24 hours a day. At 8:00 a.m. on Thursday, June 12, the baby was safely born. Both mother and child are healthy, and you can see the nursing and other child-rearing activities in the "Monterey Bay" tank. We would like to watch the baby grow up so that it will grow up healthily. Please note that the baby may be moved to the back yard depending on the situation, and you may not be able to see it. Thank you for your understanding. Appearance of parent and child (photographed on 6/12) About the newborn baby (as of June 12, 2025) (photographed on 6/12) ・Date of birth: Thursday, June 12, 2020 ・Display tank : "Monterey Bay" tank on the 7th floor of Kaiyukan・Body length: 60 cm (estimated) ・Weight: 9.4 kg (actual measurement) ・Gender: Male ・Parents: Mother Asuka (15 years old), father unknown About California sea lion English name: California sea lion Scientific name: Zalophus californianus They live only on the eastern coast of the North Pacific Ocean Ocean. When fully grown, males reach a body length of about 200 cm and a weight of about 300 kg, while females reach a body length of about 170 cm and a weight of about 100 kg. Males are dark brown all over, while females are a slightly lighter dark brown. Their limbs are well developed, which is useful not only for swimming underwater but also for walking on land. They are polygamous, with one male leading about 30 females and their children in groups called "harems." The gestation period is about one year. Usually, one child is born at a time, and the baby continues to be nursed for about one year after birth. Comments from the California sea lion aquarium keeper California sea lion breed seasonally, and the fertilization period is limited to a very short period of the year. It is very difficult to determine the date of birth by observing the behavior seen during the breeding season, such as mating. This time, the aquarium keeper and veterinarians worked closely together to determine the date of birth by regular ultrasound examinations and weight measurements, so that the mother could give birth with even more peace of mind. Because of this, on the day of birth, many aquarium keeper watched over the birth, and all the aquarium keeper were filled with joy. All the aquarium keeper in charge will continue to work together to provide care so that Asuka can raise her children with peace of mind and that the baby will grow up healthy and strong.

2025.06.12

Research and studies

Research into artificial breeding of Southern rockhopper penguin wins the Koga Award, the highest award from the Japanese Association of Zoos and Aquariums

The artificial breeding research of the Southern rockhopper penguin, which is being conducted jointly with Kasai Rinkai Aquarium, has been awarded the Koga Award, the highest award of the Japan Association of Zoos and Aquariums (JAZA), to which both zoos and aquariums belong, and was presented at the association's general meeting held on Thursday, May 22, 2025. In 2011, Kaiyukan began research aimed at elucidating the breeding ecology of this species, which is at risk of extinction in the wild and whose captive population in Japan is also declining, and establishing artificial breeding techniques. In 2016, in collaboration with Kasai Rinkai Aquarium, the world's first artificial insemination using liquid preserved semen was successfully performed on this species in the same year. In 2017, the two zoos and aquariums signed a joint research agreement and began artificial breeding using frozen preserved semen with the aim of further developing the research. In 2022, a chick born at Kasai Rinkai Aquarium was found to have been artificially inseminated using frozen semen, marking the first successful breeding of this species in the world, and in 2024, a chick born at Kaiyukan became the second successful breeding case in the world. Award ceremony at the General Assembly of the Japanese Association of Zoos and Aquariums (JAZA) (provided by Toyohashi Zoo and Botanical Gardens) In recognition of 14 years of research achievements, the Koga Award was awarded by the Japanese Association of Zoos and Aquariums. The Koga Award is the highest award given by the Japanese Association of Zoos and Aquariums to zoos and aquariums that have made outstanding contributions to the breeding of rare animals (species that are difficult to breed and are globally important). Since its establishment in 1986, 37 awards have been given, making this the 38th. Kaiyukan and Kasai Rinkai Aquarium hope to use the technology developed in this research to continue breeding the Japanese Southern rockhopper penguin through in-Aquarium breeding and, in the future, to contribute to the conservation of penguins in the wild. We will continue to work on this issue to advance research. For more information about artificial breeding research, click here. A chick born through artificial insemination using frozen preserved semen at the Kaiyukan in 2024. Artificial insemination in progress.

2025.06.04

Research and studies

Report on Kaiyukan Crowdfunding

Since its opening in 1990, Kaiyukan has been communicating the natural environment and the ecology of the creatures that live there through the display of the "Great Barrier Reef" tank , which reproduces the Great Barrier Reef , the world's largest Great Barrier Reef that spreads across northeastern Australia. After undergoing on-site diving surveys in preparation for the renovation of the tank , which was reopened on November 28 last year, we once again felt a strong desire to let more people know about the beauty of the Great Barrier Reef and the wonderful life there. As an effort to protect the future of the Great Great Barrier Reef and coral reefs, we conducted crowdfunding from June 3, 2024 to July 31, 2024, and received approximately 5.46 million yen in support. Once again, we felt the passion and warmth of our supporters through crowdfunding. We would like to express our sincere gratitude. Your donations, together with the contribution from Kaiyukan, have been combined to donate 10 million yen to the local NPO "Great Barrier Reef Legacy," which works to conserve the Great Barrier Reef. In addition, Kaiyukan has set up a "coral biobank" since last year and is working on breeding and researching coral. We look forward to your continued support.

2025.05.29

Living creature information

A first for the Kaiyukan! A large shark called the Sand tiger Shark is now on display

Kaiyukan has begun exhibiting the "Sand tiger Shark." This is the first time this species has been exhibited at Kaiyukan. Left: Male Right: Sand tiger Shark are a large shark species that can grow to over 4m in length. Contrary to their fearsome appearance with their large bared teeth, they have a docile personality and live in coral reefs, shallow offshore waters, and underwater caves. Two sharks, a 2.7m long female and a 2.5m long male, were brought to the "Pacific Ocean" tank from the Tokai University Marine Science Museum. They have now gotten used to their new environment, swimming leisurely in the tank and eating food provided by the aquarium keeper during " Feeding Time " twice a day. Exhibit location: "Pacific Ocean" tank . Individuals on display: Female: 2.7m in length, delivered on Monday, May 12, 2025. Male: 2.5m in length, delivered on Thursday, May 15, 2025. About the Sand Tiger Sand tiger Shark: English name: Sand tiger shark. Scientific name: Carcharias taurus. A large shark with a total length of over 4m. It inhabits warm seas such as coral reefs and shallow offshore waters, and in Japan, it is found in the southern Japanese waters including the Izu Islands and the Ogasawara Islands. It hides in caves on the seabed during the day and is nocturnal, active at night, feeding mainly on other fish. Contrary to its fearsome appearance, it has a gentle personality. It is viviparous, has two uteruses, and produces up to two young with a total length of about 1m per breeding. The fetuses are known to grow by eating other eggs and siblings in the uterus.

2025.04.24

Living creature information

*Exhibition has ended. [First exhibit at Kaiyukan] We are exhibiting the "megalopa larvae" of the Japanese giant spider crab.

*Exhibition has ended. Starting from April 23rd, Japanese giant spider crab larvae hatched in the "Japan Deep" tank will be on display for a limited time at the aquarium keeper counter on the 4th floor of the entrance building. On Friday, March 7th, 2025, a aquarium keeper discovered a baby Japanese giant spider crab being born in the "Japan Deep" tank and raised it carefully in the back yard. Immediately after birth, Japanese giant spider crab babies are called "zoea larvae" and have a different appearance from adults. They grow into "megalopa larvae" by repeatedly molting, and then into "juvenile crabs" that look the same as adults. They have now grown into megalopa larvae (about 3 mm), so please take a look at the precious appearance of the world's largest crab, the Japanese giant spider crab, which can only be seen now. The growth of Japanese giant spider crab larvae is also introduced in the blog "Behind the Scenery of Kaiyukan". Period: 2025/04/23~ Kaiyukan Kaiyukan Entrance Building 4F aquarium keeper Counter Species: Japanese giant spider crab megalopa larvae (approximately 3mm in size) Approximately 5 pieces *Exhibition may be canceled suddenly depending on the condition of the creatures. Japanese giant spider crab English name: Japanese giant spider crab Scientific name: Macrocheira kaempferi The world's largest crab, with males reaching over 3m in length when their tines are spread. It is also the world's largest species of arthropod, a larger taxonomic group, and is found mainly in the waters off the coast of Japan, but has also been caught in Taiwan and other places. They usually live in deep sea areas, and are known to move to shallow waters in the spring to spawn.

2025.03.28

Living creature information

[Notice] Renovation work on the "Aleutian Islands" tank [From April 9th]

Please note that the "Aleutian Islands" tank will be closed to the public from April 9, 2025 due to preparations to improve the breeding environment. Construction is scheduled to be completed after autumn 2025. We plan to report on the life of the Tufted puffin puffins in the back yard on the "Behind the Scenes at Kaiyukan " blog on the Kaiyukan website.

2025.02.26

news

[Various decorations and events will be available from March 5th!] "Kaiyukan" and "Tempozan Marketplace" are celebrating their 35th anniversaries.

On July 20, 2025, "Kaiyukan" and "Tempozan Marketplace" will celebrate their 35th anniversary. The slogan for the 35th anniversary of "Kaiyukan" and "Tempozan Marketplace" is "Heart, Huhuhu". We aim to be a place that is "a little" exciting and makes everyone's hearts laugh. The symbol mark is a "piece of excitement" that is "a little" exciting. It is designed to be like a jigsaw puzzle piece that combines to form one shape. In addition to the "Great Barrier Reef" tank, which reproduces the world's largest coral reef and was reopened on Thursday, November 28, 2024, and the coral reef associated with "35 (coral)", the design incorporates the Tempozan Giant Ferris Wheel and the Santa Maria sightseeing boat of the surrounding facilities. In addition, a special website will be opened on March 5th to celebrate the 35th anniversary. We will be celebrating our 35th anniversary with a variety of decorations and events to liven up the anniversary year, so be sure to check out the special website for event information.

2025.01.21

news

[1/28-2/3] "Demon Diver" will appear in the "Pacific Ocean" tank!

A Setsubun unique to Kaiyukan! Oni-san divers will appear in the "Pacific Ocean" tank ! From Tuesday, January 28, 2025 to Monday, February 3, 2025, divers dressed as "oni" (demons) who appear in bean-throwing events in honor of "Setsubun" will appear in the "Pacific Ocean" tank , where Whale shark live, in the "Oni-san diver" event. During the event, divers will clean the acrylic panels and bottom sand of the "Pacific Ocean" tank three times a day, and will wave to customers and take commemorative photos in between work, creating a Setsubun unique to Kaiyukan. Period: Tuesday, January 28, 2025 to Monday, February 3, 2025 Time: ①11:00- ②13:15- ③15:40- (each session is about 40 minutes) Location: "Pacific Ocean" tank Fee: Free (included in Kaiyukan admission fee) *The content may be changed or canceled without notice depending on the condition of the creatures.

2025.01.14

Living creature information

"Clione" exhibition has begun

We started exhibiting sea angels (Clione ) from Friday, January 10th. Location: "Arctic Region" in the Aquarium . Type: Sea angels ( Clione) *Exhibition may end without notice. Sea angels (Clione) In Japan, they are often called "sea angels" from their genus name "Clione". They have the Japanese name "Clione" because they are a type of shellfish that do not have a shell. They live in low-temperature waters such as the Arctic Region and its surrounding areas, and live by flapping their wing-like organs called "wing feet" and drifting in the sea. They feed on the "Mijinukimaimai", a type of shellfish, and catch them by extending six tentacles (buccal cones) from the mouth on the top of their head.