Volume 7 (2014)

PREFACE

The International Symposium of Conservation of Freshwater Crayfish was held at the Sapporo Maruyama Zoo, Sapporo,Hoklcaido (Japan) between the 11^th and 13^th January 2011.  The symposium was plannedto be international in scope and this was certainly true as presentations were given by scientists from Australia, the United Kingdom, Japan, and participants representing Russia, New Zealand, and Korea also attended the meeting. The symposium focused on the conservation biology of freshwater crayfish, but also sustainable utilization of crayfish stocks. This international symposium on freshwater crayfish conservation was historic as it was the first of its type held in Asia.

The symposium was organised by Mr. K. Tanaka of Hokkaido University, K. Ikeda and H. Yamada of Co. Pacific Consultants, and T. Nonaka of the Instituteof Civil Engineering, who kindly arranged the lectures for all who share an interest in the subject of freshwater crayfish.

Decapoda is one of the world's most important orders, especially in that it contains the freshwater crayfish in the Astacida, and superfamilies Astacidea and Parastacidea. Freshwater crayfish are the largest mobile freshwater invertebrates and there are over 550 species. There has been, and very likely will continue to be a rapid change in the focus of research on freshwater crayfish. In Europe, North America, and Australia, fisherman and aquaculturists have historically targeted freshwater crayfish, and freshwater crayfish have also been of long-standing interest to anatomists and physiologists.

However, more recently many species of freshwater crayfish have been designated as "endangered species" in many regions of the world, and at present much research on freshwater crayfish is focused on ecology and conservation biology.  One solution to the outstanding problem of conservation of freshwater crayfish was to develop the fields of basic taxonomy, biology and ecology, field research techniques, and stock population management.

Japan has a single native species, Cambaroides japonicus, and two alien species from North America; Pacifastais tacusleniusculus and Procambarus clarkii. Conservation of the native species has been a recent and important issue, due to that fact that in Japan, and other countries, many native crayfish species are threatened by human activity, and competition and disease from alien crayfish species. In this regard, the symposium and publication of the resulting Special Issue of Crustacean Research is timely and meaningfu1 as it will be valuable resource to regional wildlife managers, scientists, and especially conservationists from all regions of the world.

The Special Issue of Crustacean Research is the volume resulting from this International Symposium of Conservation of Freshwater Crayfish. In total, the symposium has resulted in 15 selected papers, of which 10 are original research articles and were anonymously peer-reviewed, and five other papers that were submitted as reports. All 10 original research articles were examined by at least 2 anonymous reviewers and the editor, and a total of 25 reviewer comments or suggestions were submitted on the articles. In some cases the reviewer's comments substantially improved the quality of the articles, and the 21 reviewers are listed in the acknowledgements section. I have compiled this Special Issue expressly for wildlife managers, scientists and conservationists from all regions of world, especially those who want to have an impact beyond their own fields of expertise.

In closing, I would like to sincerely thank the symposium sponsors, Co. Pacific Consultants and Sapporo Maruyama Zoo, for providing the financial assistance for this symposium. Special thanks are due for the work of the many experts who reviewed the manuscripts for this Special Issue.  Also, I wish to express appreciation to the Crustacean Society of Japan, for publishing this issue, and to the participants in this symposium; the secretaries, students, speakers, and panelists.

Tadashi Kawai

Hokkaido Fisheries Research Institute

Hokkaido, JAPAN