Aqua World Oarai has begun exhibiting Australian lancewell shark eggs for the first time, starting May 14th, 2026 (Thursday).

The Australian swell shark inhabits the shallow waters to depths of up to 60 meters off the southwestern Pacific Ocean and the southern coast of Australia, and can grow up to 150 cm in length. It is a species closely related to the Japanese swell shark found in Japanese waters. The eggs of the Japanese swell shark and its relatives are sometimes called "mermaid's purses" due to their shape and size. While the eggshells of the Japanese swell shark have a smooth surface, the eggs of this species have a beautiful curved, uneven surface with a distinctive wavy pattern. The meaning of this pattern is not yet fully understood. The eggs on display are developing well, and visitors can observe the baby sharks growing inside the eggs.

Australian swell sharks are a species that we have never kept in captivity before, and there are many unknowns about them. For our shark keepers, this is the first time they have seen these eggs, and the first time they have seen hatched baby sharks. The keepers are looking forward to the birth of new life growing inside the eggs. We encourage everyone to observe the eggs and imagine what kind of baby sharks will hatch from them.

"Samekko Room" introduces shark breeding research at Aqua World Oarai.

At Aqua World Oarai, we are also focusing on breeding sharks to better understand their ecology. On the 5th floor, in the "Shark Room," we exhibit baby sharks born at our facility and introduce the latest information on shark breeding research at our aquarium. Along with this egg exhibit, we encourage you to take this opportunity to learn more about our efforts.