彼得森黄群藻孢囊的形成及形态

利用光镜及扫描电镜对彼得森黄群藻的形态结构、孢囊形成进行详细观察和描述.结果显示,彼得森黄群藻分布广泛,营养体形态变化也大,可以分为不同的变种和变型,其孢囊形态也有多种形态.根据鳞片结构,鉴定出其中的2个变型,并对其所产生的孢囊形态进行了对应.     

OLSTHODISCUS LUTEUS (CHRYSOPHYCEAE) II. FORMATION AND SURVIVAL OF A BENTHIC STAGE1

Motile unicells of Olisthodiscus lutheus Carter aggregated to form encapsulated masses of nonmotile cells in a benthic stage throughout a temerature range of 15–30°C at salinities o f 10–50%. Motile cells were released from beneathic masses at 10–30°C but at 5°C, cells were not motile and at 0°C cells lysed. Exposure of benthic masses of I day to 8 wk to temperatures of 0–30C in lighted growth chambers resulted in mortality to cells kept below 10°C and normal growth at higher temperatures. Benthic stage cells kept tn darkness at the same temperatures exhibited mortality in all but those at 5 and 10°C. Cells at these thmoeratures remained viable 15 wk in continual darkness. Comparison of cell morphology of matile and benthic stage O. luteus to other Olisthodiscus species and the ecological implications o fthe benthic stage are discussed.     

Palaeoecological significance of chrysophycean stomatocysts: a statistical approach

The statistical relationship between chrysophycean cyst abundances and ecologically known factors, derived from multivariate analyses, is proposed as a useful way to derive palaeoecological information of non-identified cysts. The method is applied to a case-study from the Spanish Pyrenees, and encouraging results are obtained for some of the morphotypes found.