Proceedings of the International Symposium

Reproduction of Marine Life, Birth of New Life!
Investigating the Mysteries of Reproduction
February 21-22, 2009, Okinawa Churaumi Aquarium, 2009

Editor
Keiichi Sato
Okinawa Churashima Research Center2013

Proceeding of the International Symposium
Reproduction of Marine Life, Birth of New Life!
Investigating the Mysteries of Reproduction
February 21-22, 2009, Okinawa Churaumi Aquarium

Editor
Keiichi Sato

Published by:
Okinawa Churashima Research Center
Okinawa Churashima Foundation
888 Ishikawa, Kunigami-gun
Motobu-cho, Okinawa 905-0206
JAPANCopyright ©2013
Okinawa Churashima Foundation

Cover design: Keiichi Sato
Layout: Keiichi Sato
Date of Publication: 20 August 2013

Preface
With great pleasure we are publishing the Proceedings of the International Symposium on Reproductionof Marine Life which was held here in February, 2009.

The Symposium, entitled “Birth of New Life! Investigating the Mysteries of Reproduction” was hosted
by the Ocean Expo Commemorative Foundation (currently Okinawa Churashima Foundation) which
manages the Ocean Expo Park with the Okinawa Churaumi Aquarium, and the Shurijo Castle Park, bothbelonging to the National Government Park System. We received many visitors for an average of 2.67million visitors per year, and in fiscal year 2007 we recorded a total of over 3 million visitors for the firsttime.

We would like to express our sincere thanks to all the researchers who contributed to this Proceedings
volume, travelling such a long way to attend the Symposium in Okinawa, and then writing theircontributions for publication here.

We have already held three International Symposia, entitled “Elasmobranch Studies, Present Achievement
and Future Advancement” in 2004; “Recent Advances in Cetology and Sirenology” in 2006; and “Into theUnknown, Researching Mysterious Deep-sea Animals” in 2007.

However, during those Symposia,

mostly ecological and field studies in the coral reefs and open oceans were discussed. Thus, for thisSymposium, we chose the leading characters to be Reproductive Biology especially on the captive
reproduction in aquarium researches. Concerning marine wildlife, and especially large-sized marine life,
there are still many unknowns, and too many mysteries yet to be solved!

We can only make long-term studies of the physiology and ecology of many marine animals by keeping
them in captivity. At the symposium, our Symposium participants actively discussed a wide range ofsubjects concerning reproduction, and especially, included in their discussions the role of aquariums topromote and develop studies of the reproductive biology.

20 August 2013

Mr. Yoshiya Iguchi
Director, Okinawa Churashima Research Center
Okinawa Churashima Foundation

Contents

Gavin Naylor and Neil Aschliman
How many species of living sharks, skates and rays are there, and how did they arise over thecourse of evolution?
Page 5 - 12

Hiroaki Soma, N. Murai, K. Tanaka , H. Kokuba, I. Yoshihama, K. Fujita, S. Mineo, M. Kudo, M. Toda
and S. Uchida
Aspects of placentation systems in the scalloped hammerhead shark, Sphyrna lewini, and themanta ray, Manta birostris.
Page 13 - 22

David Wm. Owens and Gaëlle Blanvillain
Captive reproduction of sea turtles: An important success story.
Page 23 - 40

Miriam Marmontel
Conservation of Amazonian manatees in Brazil with emphasis on reproductive aspects
Page 41 - 51

Jose I. CastroA primer on shark reproduction for aquarists
Page 52 - 69

田 中 秀 樹Hideki Tanaka

ウナギ人工種苗生産研究の現状と課題
Artificial production of Japanese eel Anguilla japonica (in Japanese)
Page 70 - 76