Niji no Mori Park Osakanakan Aquarium

This small aquarium is located inside the Niji no Mori Koen Matsuno roadside station. Focusing on the ecosystems of the Shimanto River, said to be Japan’s clearest river, and its tributary, the Hiromi River, the aquarium primarily introduces freshwater fish. More than simply a place to observe fish, it offers an engaging way to learn about the mysteries of rivers and the connections between living creatures.

Exhibits include fish from the Shimanto River as well as freshwater species from tropical rivers such as the Amazon and Mekong. Visitors can see around 100 species, including the akame, a large fish associated with the Shimanto River and considered one of Japan’s three great monster fish, and the pirarucu, one of the world’s largest freshwater fish. The aquarium is also home to distinctive animals such as adorable penguins and Asian small-clawed otters gliding gracefully through the water.

On weekends, national holidays, and during extended school breaks, the aquarium also holds events offering up-close encounters with the animals, including penguin walks, otter snack time, and feeding experiences.
Penguin walks and interactive encounters are suspended from November through April or May to help prevent avian influenza.