What is the Hanzaki Research Institute of Japan?

It is a professional research institute of the Japanese Giant Salamander and represents a generic name for a collection of facilities for research, environmental education, community exchange as well as a museum. “Hanzaki” was once the standard Japanese name for the Japanese Giant Salamander and Ankou is a local name in this area. The common name in Japanese is now Ōsanshōuo (オオサンショウウオ).



*Please be noted that the institute is not open to the public. Please contact us at info@hanzaki.net if you could like to visit the institute. We strive to respond to your email within 72 hours. However, we are understaffed and would appreciate your understanding in case that we were not able to respond in a timely manner.

The Hanzaki Research Institute of Japan located right next to Ichikawa River
The Hanzaki Research Institute of Japan located right next to Ichikawa River

Announcement of Mr. Tochimoto’s Death

Mr. Takeyoshi Tochimoto, former director of the NPO Hanzaki Research Institute of Japan, passed away on May 28, 2019, at 13:22 pm. On behalf of the deceased, we would like to thank all of you for supporting the institute for many years.


Because of the fever of an unknown cause that started in May 2019, he became weak for a long period and eventually returned to Himeji for hospitalization.


We regret deeply for his death especially because we were informed that he was able to take meals little by little and was recovering.


Please understand that the funeral was held only by the family, and they decline condolatory calls and flowers.

We sincerely pray that Mr. Tochimoto’s soul may rest in peace.

We look forward to your continued support and cooperation.


Sumio Okada, PhD

Director of the NPO Hanzaki Institute of Japan

Our New Director

Dr. Sumio Okada succeeded the directorship of the institute from Mr. Tochimoto in 2017 who was active as an honorary president until his death. Now the institute made a new start under Dr. Okada’s directorship. Dr. Okada is the world’s leading authority on Japanese giant salamanders with 20+ years of experience with this species. His research currently focuses on parental care behaviors, breeding ecology, population assessment, and human impacts. He has published extensively and appeared on numerous nature documentaries.

The Hanzaki Institute and Asago City are hosting 17th Annual Japanese Giant Salamander Conference in 2020!

We are excited to announce that we are the host for the next Annual Conference. The past conferences have been domestic and targeted only Japanese participants. In 2020, we are making the conference international and inviting not only Japanese but also international participants. Please be noted that it is an invitation-only conference. If you are a member of CIG (Cryptobranchid Interest Group), you will receive an invitation. If you are not a CIG member but are involved in amphibian conservation research/education, please contact us for the details of the conference.  

13th Conference at Onan Town, October 2018
13th Conference at Onan Town, October 2018

On-going Research Projects

Whereas we work with the Prefectural and the local governments for outsourcing population surveys, we actively seek grants from private companies and organizations for our own research summarized below. 

Population Monitoring

Our main research project is to monitor the giant salamander population in Ichikawa River. We regularly wade through the river at night, find giant salamanders, and take various measurements. To date, we identified over 1700 individuals and most of them are identified with microchips. By comparing data and measurements over time, we are working to resolve mysteries behind the life cycle of the Japanese Giant Salamander such as longevity and growth rate.

Population Assessment - Collaboration with Bucknell University

Dr. Mizuki Takahashi’s lab at Bucknell University and we are assessing populations in small un-surveyed tributaries using the environmental DNA method. We currently know little about the importance of those small streams (1 to 3 order streams) to the cycle history of giant salamanders. Despite the small size, those streams may provide important habitats for larval and juvenile giant salamanders. Dr. Takahashi led a summer research program with three Bucknell Students during the summer of 2018. They stayed at the Institute for about a month, conducted the eDNA research, and interacted with the locals including students from Ikuno High School. 



Three Bucknell Students taking water samples for eDNA analysis.
Three Bucknell Students taking water samples for eDNA analysis.

Breeding Ecology - Collaboration with Azabu University

Dr. Kumi Matsui’s lab at Azabu University and we are assessing breeding status of salamanders by analyzing reproductive hormones in blood samples and using a portable ultrasound device. Dr. Matsui’s lab visits the institute throughout the year and monitor how reproductive organs and hormones change in response to their breeding activity.

Dr. Matsui and her students taking blood samples
Dr. Matsui and her students taking blood samples

Population Monitoring within our Community - Collaboration with Ikuno High School

Students from the local Ikuno High School and we just started monitoring of the giant salamander population in front of the Ikuno High School located in Ikuno Town. It is our mission to engage our community members in conservation and promote environmental education among the young. We are developing a long-term collaborative relationship with the high school.

Students from Ikuno High School learning about the ecology and the conservation issues surrounding the local giant salamander populations at the Hanzaki Institute (Mr. Tochimoto on right)
Students from Ikuno High School learning about the ecology and the conservation issues surrounding the local giant salamander populations at the Hanzaki Institute (Mr. Tochimoto on right)

Future Collaborators

We are actively seeking collaborators to promote research and conservation of Japanese Giant Salamanders. Please contact us if you are interested.

Donations to the Institute

We sincerely thank to the following organizations and individuals for their generous supports. We are a non-profitable organization that solely depends on memberships, grants, and donations for the management of the institute. In particular, donations enable us to continue and expand our research. We would greatly appreciate your support.

Honolulu Zoo (2014, 2015, 2016, 2017, 2018, 2019, 2020)

-          Laura Debner


 Curator of Reptiles/Amphibians and Children's Zoo/ Conservation Chair

San Antonio Zoo (2016)

-          Danté Fenolio, PhD


 Vice President of Conservation and Research

Detroit Zoological Society (2017, 2018, 2019, 2020)

   - Paul Buzzard, PhD

    Field Conservation Officer

   - Ruth Marcec, DVM, PhD

    Director of the National Amphibian Conservation Center

If you are able to support us, please contact us at info@hanzaki.net. If you prefer sending us donation directly, here’s the information.








1696 - 001 - 5085835


(Paying Bank)



 NPOhojin Nihonhanzakikenkyusho rijicho Okada Sumio