A new species of Isochrysis(Isochrysidales)——I.zhanjiangensis and its observation on the fine structure

A new species of genus Isochrysis I.zhanjiangensisi sp.nov.H.J.Hu, SH Let H.R.Liu was reported in this investigation.It was sampled and isolated from Nansan Island of Zhanjiang of Guangdong Province, China.The fine structure of its motile cells was observed through transmission electron microcope (TEM).The cellular surface is covered with 2~4 layers of scales with two different types of shape:either larger elliptical scales or smaller circular ones.Two equal, smooth flagella are protruded at the anterior end of the cell.Between the two flag ella is a very short and rudimentary hapto nema consisting of one or two microt ubules.The flagella transitional region is wound by 5~6 turns of a helix between centralax onema and peripheral microtubules.There are two golden brown chloroplasts situated on two parietal sides of the cell.Within the stoma are stacks of Thylakoids and a stack of three thylakoids consists of a Granum lacking girdle lamellar.In the cytoplasm of a cell, there is naked-pyrenoid wrapped with a single layer of membrane.An array of thy lakoids is typically shaped transversely with pyrenoid.The Golgiapparat us is located in the base of the flagella.Mitochondria are usually long, tubular in shape with branched or unbranched cristae.One to several chrysolaminaran granules are widely distributed in the middle or later of the cell.The nucleus lies between two plastids at the base of the cell.