Makoto Urata,¹ Nobuo Yamaguchi,² Yasuhisa Henmi,³ Kinya Yasui<sup>1,*

1</sup>1Marine Biological Laboratory, Graduate School of Science, Hiroshima University, 2445 Mukaishima, On
²2Hiroshima University Technical Center, 2445 Mukaishima, Onomichi, Hiroshima 722-0073, Japan
³3Aitsu Marine Station, Center for Marine Environmental Studies, Kumamoto University, 6061 Aitsu, Kam

^** Corresponding author. Phone: +81-848-44-1143; Fax : +81-848-44-5914; E-mail: furaha@sci.hiroshima-u.ac.jp