An investigation on microplankton composition and spatial distribution has been carried out around Italian seas. The analysis of 53 samples, collected in 2017 at two depths in 27 different stations, has led to a scenario of horizontal distribution of microplankton. Dinophyta and Ciliophora were chosen as representatives of the whole microplankton community. A total of 60 genera were identified. Cluster analysis of data regarding taxa presence and abundance led us to recognize that similarities between surface stations were more evident than those between deep ones. Furthermore, we conducted an inter-annual comparison with available data from the South Adriatic Sea (2013, 2015). The higher dissimilarity between deep sea samples was also confirmed in a relatively smaller geographic area. The dissimilarity of deep-sea samples does not correspond to a higher habitat diversification, in terms of abiotic parameters. It has been suggested that the negligible biological connectivity in the deep, for those micro-organisms not able to perform wide spatial migrations, could produce such a biological diversification.

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深海微浮游生物的水平分布：海洋生物地理学的新观点

已经在意大利海域对浮游植物的组成和空间分布进行了调查。对2017年在27个不同站点的两个深度收集的53个样本的分析导致了微浮游生物的水平分布。Dinophyta和Ciliophora被选为整个微浮游生物群落的代表。总共鉴定了60属。关于分类单元存在和丰度的数据的聚类分析使我们认识到，地面站之间的相似性比深层站之间的相似性更为明显。此外，我们还与南亚得里亚海（2013年，2015年）的可用数据进行了年度间比较。在相对较小的地理区域内，也证实了深海样本之间较高的相似性。就非生物参数而言，深海样品的差异性并不对应于更高的栖息地多样化。已经提出，对于那些不能进行广泛的空间迁移的微生物来说，深处的生物连通性可以忽略不计，可以产生这种生物多样性。