众所周知,生物生长取决于所栖息的环境,作为海洋主要的微体植物之一的硅藻,当然也遵循这一规律,受制于海洋地理环境如物理、化学、生物等因素。仅就盐度而言,可以分出广盐种、狭盐种;而就生活方式而言,就有底栖种和浮游种之分。大洋每克悬浮物(干样)中硅藻个体的数量从6.25百万个到4亿多个,每克沉积物(干样)中的含量从0到大于1亿个个体(Lisitzin,1971),说明海洋地理环境的差异不仅造成了硅藻种类性质的不 It is well-known that biological growth depends on the environment inhabited. Diatoms, one of the major marine micro-organisms, of course, follow this rule and are subject to the marine geographical environment such as physical, chemical and biological factors. Only in terms of salinity, can be divided into wide-salt species, salt species; and way of life, there are benthic species and plankton species points. The number of diatoms individuals per gram of suspended matter (dry sample) in the ocean ranges from 6.25 million to more than 400 million, with levels ranging from 0 to more than 100 million individuals per gram of sediment (dry sample) (Lisitzin, 1971) , Indicating that differences in the marine geography not only caused the nature of diatoms species do not