Environmental characteristics of Pyropia tenuipedalis(Miura)Kikuchi et Miyata growing at Yamaguchi Bay, Yamaguchi Prefecture

山口県山口湾に自生するカイガラアマノリPyropia tenuipedalis(Miura)Kikuchi et Miyataの生育環境

Environmental characteristics of Pyropia tenuipedalis(Miura)Kikuchi et Miyata growing at Yamaguchi Bay, Yamaguchi Prefecture

Creators Abe Mahiko

Creators Murase Noboru

Creators Hatama Toshihiro

Creators Shikano Yosuke

Creators Kanai Taisei

This study surveyed environmental characteristics of Pyropia tenuipedalis foliose thallus growing at Yamaguchi Bay, Yamaguchi prefecture from November to March, 2010-2014. Young foliose thallus of this species appeared in December and grew to maximum length from January to March. In March, mature thalli were observed. In 2012-2013, only 3-10 individuals were found in each survey. Water temperature from November to March was the range of 6-16℃, but early December in 2012 was lower than other years. Light reaching to the growing site of this species was 6.2±3.1% of water surface in high tide. DIN (ammonia + nitrate + nitrite) at the sampling site was the range of 8.8-68.3μmol L^{-1}, and approximately 10 times higher compared wih those of waters which assume to cause the discoloration of Susabi ? nori. Water temperature falling rate from November to December in 2012-2013 was 0.33℃ day^{-1} and this was higher value than those of other years. In this study, it was suggested that the growth of thalli from spherical cell was inhibited by long or short term rapid water temperature falling which occurred from November to December.

[ISSN]0370-9361