中文摘要：

研究报道了采自中国四川九寨沟自然保护区长海的4种中心类硅藻种类,其中新种1个:长海小环藻(Cyclotella changhaisp.nov.),中国新记录种1个:克里特小环藻(C.cretica)和2种较少报道的种类:可辨小环藻(C.distinguenda)和辐纹琳达藻(Lindavia radiosa)。通过光学显微镜和扫描电子显微镜对这4个种类形态学的特征进行观察,并与相似种类进行比较。与长海小环藻相似的种类包括C.comensis Grunow,C.pseudocomensis Scheffler和C.costei Druart&Straub,主要通过壳面中央区的不同形态进行区分-长海小环藻的中央区近平滑且具有不规则的凹陷。

英文摘要：

In this study,four centric diatom are reported from Lake Changhai in Jiuzhaigou Valley,SichuanProvince,China.One new Cyclotella species:Cyclotella changhai sp.nov.,one newly-recorded species fromChina:Cyclotella cretica,and two rare reported centric diatoms:Cyclotella distinguenda and Lindavia radiosa.The morphology of these four species is documented by light and scanning electron micrographs andcompared with similar species.Cyclotella changhai sp.nov.is similar to C.comensis Grunow,C.pseudocomensisScheffler and C.costei Druart&Straub,but is distinguished from them by the structure of the centralarea in the valve:nearly flat central area with irregular depressions.