A male Alfred manta ray, born on June 17th 2008 and raised successfully at Churaumi Aquarium, was confirmed to reach sexual maturity.

※Currently this manta ray is in the sea pen and not displayed here at the aquarium.

≪Alfred manta ray (reef manta ray)≫
Scientific name：Mobula alfredi

The second largest species of ray. It inhabits temperate and tropical waters of the Indo-Pacific including Okinawa. The world’s first successful captive reproduction of the manta ray was achieved at Churaumi Aquarium.

This male manta ray was born on June 17th, 2008. Since his birth, staff from the Okinawa Churaumi Aquarium and the Okinawa Churashima Foundation Research Center have monitored in detail the manta’s external changes and hormonal concentrations within his blood. The results show that this male manta ray reached sexual maturity after 5 years.

Until now, knowledge of sexual maturity in manta rays was reliant on fragmentary information from visual observation in the wild. The precise age of maturity and the maturation process had not been observed. The monitoring conducted over the past 7 years is the only report in the world where a single individual has had its growth, physiology, morphology, and behavior tracked. This was only possible through long-term husbandry. It is also an important piece of research to protect this species amid worries about population loss.

The male manta ray continues to grow well in the Churaumi Aquarium’s sea pen in which he has mated with a female manta ray. We will continue to study their reproduction and the rearing of a next generation of manta rays.

Okinawa Churaumi Aquarium will contribute to wildlife conservation through further research including developing health management technologies and reproduction research.

Details and the results of monitoring were published in the international journal BMC Zoology.
Journal：BMC Zoology (2017) 2:14
DOI 10.1186/s40850-017-0023-0
Title：High-resolution monitoring from birth to sexual maturity of a male reef manta ray, Mobula alfredi, held in captivity for 7 years: changes in external morphology, behavior, and steroid hormones levels
Author：Ryo Nozu, Kiyomi Murakumo, Rui Matsumoto, Yosuke Matsumoto, Nagisa Yano, Masaru Nakamura, Makio Yanagisawa, Keiichi Ueda and Keiichi Sato