Indo-Pacific bottlenose dolphins

Okinawa Churaumi Aquarium is the only place in Japan that rears the Indo-Pacific bottlenose dolphin. The Churashima Foundation has analyzed the reproductive capability of elderly male Indo-Pacific bottlenose dolphins (approximate age of 47 to 50 years). The staff monitored the levels of the hormone testosterone in blood samples, and the quality of the semen. The results showed that testosterone levels rise and then lower from spring to autumn. The sperm concentration suggests that even elderly male Indo-Pacific bottlenose dolphins are still able to breed. (The lifespan of wild Indo-Pacific bottlenose dolphins is thought to be 35 to 40 years). The results of these studies are important considerations for the future captive breeding of dolphins.