一种硅藻中国新记录属种——科氏杜氏藻

科氏杜氏藻是一种泥生或附沙生硅藻。该文对最近刚确立的一个硅藻属——杜氏藻属进行了介绍,利用光学和扫描电子显微镜对2019年4月20日采自东洞庭湖国家级自然保护区的科氏杜氏藻标本进行了观察研究。结果表明该标本具有以下主要形态特征:(1)壳面椭圆披针形。(2)中央区为蝴蝶结形,没有延伸至壳缘。(3)线纹在壳面大部分区域呈辐射状排列,在两端近平行排列,中部线纹密度20~22条/10μm。(4)孔纹圆形或近圆形,在内壳面被圆顶状的孔膜覆盖。(5)在壳面两端存在假隔片。该文调查采集的科氏杜氏藻种群的形态特征与模式种群相吻合,该属在中国是首次报道,为中国新记录属。

Dorofeyukea kotschyi (Grunow) Kulikovskiy, Kociolek, Tusset & T. Ludwig, a New Diatom Genus and Species Record from China

Dorofeyukea kotschyi is an epipelic or epipsammic diatom.This paper introduces a recently erected diatom genus Dorofeyukea and studies the specimens of D.kotschyi from the East Dongting Lake National Nature Reserve using light and scanning electric microscopy.The results show that D.kotschyi possesses the following main characters:(1)elliptic-lanceolate valves;(2)a butterfly-shaped fascia,but not across the valve face;(3)radiate striae on the most valve surface where stria density is 20-22/10μm,except at the two apices where striae are parallel;(4)the nearly rounded areolae and the inner areola openings covered by dome-shaped hymens;(5)a pseudoseptum occurring at both apices.The features of the D.kotschyi population investigated in this study fit well the ones of the type population,and the genus Dorofeyukea is reported in China for the first time,thus,this paper in fact reports a new genus record and a new diatom record.