Overview of Kaiyukan
Kaiyukan’s exhibitions are based on the themes of the “Ring of Fire”, referring to the Pacific Ring of Fire, and the “Ring of Life,” representing the rich ecosystems surrounding the Pacific Ocean.
The aquarium features 14 large-scale tanks, where visitors can observe impressive marine animals such as whale sharks and manta rays at close range. The facility ranks among the largest aquariums in the world and is home to approximately 580 species and 30,000 individual animals.
The exhibits recreate a wide variety of natural environments. Highlights include the tunnel-style “Aqua Gate”, the penguin-filled Antarctica exhibit, the Ecuadorian Rainforest with capybaras and arapaima, and the Japanese Forest, home to Asian small-clawed otters and Japanese giant salamanders.
The dedicated “Jellyfish Galaxy” is another popular attraction, offering an immersive experience focused entirely on the fascinating world of jellyfish.
Kaiyukan is operated by Kaiyukan Co., Ltd. and forms one of the main attractions of the Osaka Bay area together with nearby Tempozan Marketplace and the Tempozan Giant Ferris Wheel.
Architecture and Design
The exterior of Kaiyukan is characterized by a three-color design inspired by the elements of earth, water, and fire. The overall building was designed by American architect Peter Chermayeff.
Fish murals decorate the exterior walls. These artworks were created by his father, Serge Ivan Chermayeff.
Advanced technology was incorporated into the aquarium’s design, particularly the use of enormous acrylic panels that made it possible to create exceptionally large tanks.
The Pacific Ocean Tank is the centerpiece of the facility, where visitors can watch whale sharks swimming gracefully through an enormous underwater environment.
A Journey Through the Pacific Rim
The entire building is designed to represent the “Ring of Life” around the Pacific. Visitors begin on the upper floors and gradually descend through the building, observing marine and terrestrial environments representing different regions.
The route is designed so that animals can be viewed from different heights and perspectives. As visitors move downward, they may encounter the same animals from completely different angles, creating a dynamic experience that resembles traveling through their natural habitats.
Innovative Aquarium Water Management
Kaiyukan uses a distinctive water-management system in its large tanks. Instead of simply exchanging water in a conventional manner, water is introduced from the bottom of the tanks and discharged from the top.
This creates a continuous current that helps remove leftover food and waste while maintaining water clarity and a suitable environment for the animals.
Oxygen is supplied using artificial waterfalls, some of which have been designed so that visitors can see them as part of the aquarium exhibits.
Whale Sharks and Manta Rays
The Pacific Ocean Tank is one of Kaiyukan’s most famous attractions. The aquarium achieved major milestones in keeping whale sharks and manta rays in captivity.
When Kaiyukan opened in 1990, it was the only aquarium in the world keeping a whale shark. In 2008, Kaiyukan also became the first facility in the world to exhibit a manta ray in captivity.
Today, Kaiyukan and Okinawa Churaumi Aquarium are the only aquariums in Japan keeping this species, according to the source information.
The Pacific Ocean Tank
The enormous Pacific Ocean Tank measures approximately 34 meters in length, reaches a depth of about 9 meters, and holds approximately 5,400 cubic meters of water.
Approximately 100 acrylic panels form the tank walls. The panels were produced by companies including Mitsubishi Rayon and Sumitomo Chemical.
In addition to whale sharks and manta rays, visitors can observe a wide variety of marine life, including scalloped hammerhead sharks and spotted eagle rays.
Major Exhibition Areas and Featured Animals
Fish Tunnel — Aqua Gate
The Aqua Gate is a tunnel-shaped aquarium where fish swim overhead and around visitors. Species such as cowtail stingrays and convict tangs can be seen here.
Walking through the transparent tunnel creates the sensation of moving through an underwater world.
Japanese Forest
This exhibit recreates a Japanese natural environment and introduces animals such as Asian small-clawed otters, Japanese giant salamanders, and common mergansers.
Monterey Bay and the Aleutian Islands
This area features animals from the cold waters of the North Pacific and the western coast of North America, including harbor seals, California sea lions, and tufted puffins.
Antarctica and the Arctic
Visitors can encounter animals adapted to some of the coldest environments on Earth, including king penguins and sea angels, also known as clione.
The cool environment recreates the atmosphere of polar regions and provides a striking contrast to the warmer tropical exhibits.
Ecuadorian Rainforest
The Ecuadorian Rainforest introduces the diverse wildlife of tropical South America. Featured animals include capybaras, piranhas, and polka-dot stingrays.
Other Exhibition Areas
Great Barrier Reef: Home to colorful species such as blue tangs and damselfish.
Tasman Sea: Features Pacific white-sided dolphins.
Deep Sea Zone: Introduces unusual deep-sea creatures such as giant isopods and spiny lobsters.
Japan Trench: Features deep-sea animals found around Japan, including Japanese spider crabs and giant Pacific octopuses.
Facilities Beyond the Aquarium Exhibits
Kaiyukan offers more than its main animal exhibits. Visitors can also enjoy several additional facilities and services.
Special Exhibition Hall
The Special Exhibition Hall hosts temporary exhibitions on a variety of themes, providing visitors with new experiences throughout the year.
Kaiyukan Hall
Kaiyukan Hall is an event space with seating for approximately 320 people and is used for various programs and events.
Restaurant Harbor View
Restaurant Harbor View offers dining with views toward the surrounding waterfront, providing an opportunity to take a break while enjoying the atmosphere of Osaka Bay.
Official Museum Shop
The renovated museum shop features a wide selection of original souvenirs and merchandise. Designs by internationally active designer Moe Nozu and the design unit COCHAE are among the highlights.
The shop is designed to create the feeling of strolling across the surface of the water, making shopping itself part of the Kaiyukan experience.
Kaiyukan’s Achievements and Initiatives
Milestone Visitor Numbers
On February 26, 2008, approximately 18 years after opening, Kaiyukan welcomed its 50 millionth visitor. At the time, this was the fastest achievement of that milestone among aquariums in Japan.
For its 30th anniversary in 2020, Kaiyukan renovated its entrance building and renewed its museum shop, providing visitors with an updated experience.
The Story Behind the Name “Kaiyukan”
The name “Kaiyukan” was selected with advice from television personality Emiko Uenuma.
When the aquarium invited the public to submit name ideas, many proposals included the word “Marine.” Uenuma suggested “Kaiyukan,” noting the distinctive sound and visual impression of the Japanese characters. The name was ultimately adopted.
James Rouse and the Aquarium Project
James Rouse, the grandfather of actor Edward Norton, is also known for his involvement in planning the Kaiyukan project. According to the source information, Norton himself stayed in Osaka and helped with the establishment of the facility.
Seasonal Events and Special Exhibitions
Kaiyukan organizes seasonal events that add an entertaining element to its educational programs.
Oni Diver
During the Setsubun season, the popular “Oni Diver” event features staff members dressed as traditional Japanese demons, or oni, while cleaning the aquarium tanks.
This playful event allows visitors to enjoy a memorable experience while learning about aquarium maintenance and marine life.
Evening Aquarium Experience
Visitors who complete the re-entry procedure can return to the aquarium multiple times on the same day.
Entering after 5:00 p.m. also provides an opportunity to observe the aquarium’s animals as they transition into their nighttime behavior.
Animals Previously Exhibited at Kaiyukan
Over the years, Kaiyukan has cared for and exhibited a wide variety of animals, including sea otters, oceanic manta rays, bluefin tuna, finless porpoises, and squirrel monkeys.
These exhibitions have provided visitors with opportunities to learn more about the diversity of marine ecosystems and the natural world.
A World of Marine Life at Kaiyukan
Kaiyukan attracts visitors from Japan and overseas with its enormous scale and diverse range of exhibits. The spectacular Pacific Ocean Tank and its whale sharks and manta rays are major highlights, while the many regional exhibits allow visitors to experience environments ranging from tropical rainforests to the polar regions.
The aquarium also offers distinctive shopping, seasonal events, special exhibitions, and opportunities to experience the animals at different times of day.
With its combination of education, entertainment, architecture, and immersive wildlife exhibits, Kaiyukan is a popular destination for families, couples, and travelers interested in Japan’s marine life.