Species diversity of pasture grass Skeletonema in the world sea and assessment of its classification

2007年10月和2008年1月至2009年12月，在日本工业港口东开湾的一个站点，通过形态扫描电子显微镜观察和主要大亚基(LSU)rDNA的分子分析，鉴定出7种骨架线虫。我们使用LSU rDNA将一个种鉴定为S.dohrnii，但使用小亚单位(SSU)rDNA将其称为S.marinoi，因此我们使用术语S.marinoi-dohrnii复合体。这是首次在日本记录到S.ardens、S.costatum S.S.和S.Passocostatum，并在日本用分子方法鉴定了S.menzelii和S.tropicum。Marinoi-dohrnii复合体常年高频率分离，日本血吸虫也高频率分离，夏季分离频率较低。热带沙门氏菌(S.tropicum)是从9-12月分离出来的，而华登沙门氏菌(S.ardens)和肋骨沙门氏菌(S.costatum S.S.)则是从9-12月分离出来的。只有在水温超过20℃时才能分离到。假肋骨条藻只在夏季开花一次，但门泽氏链霉菌在5月份和10月份再次被分离。中肋骨条锈菌S.1的连续发生。是由这七个物种的演替支撑的。除门泽尔氏藻外，有六种藻类是海湾藻华的重要组成部分。每月分离出1~4种骨骼线虫。当分离出通常与热带或亚热带水域有关的S.ardens、S.costatum S.S.和S.tropicum时，每月的物种多样性较高。总体而言，东开湾的骨架线虫属物种多样性很高。

Seven Skeletonema species were identified at one station in the industrial harbor Dokai Bay, Japan, in October 2007 and then monthly from January 2008 to December 2009 by morphological scanning electron microscopy observations and molecular analyses of mainly the large subunit (LSU) rDNA. We refer to one species identified as S.dohrnii using LSU rDNA, but as S.marinoi using the small subunit (SSU) rDNA and consequently we use the term S. marinoi-dohrnii complex. This is the first time that S.ardens, S. costatum s.s., and S.pseudocostatum have been recorded in Japan and that S.menzelii and S.tropicum have been identified by molecular methods in Japan. The S. marinoi-dohrnii complex was isolated with high frequency all year-round, and S.japonicum was also isolated with high frequency but not so in summer. S.tropicum was isolated from September to December, but S.ardens and S. costatum s.s. were isolated only when the water temperature exceeded 20℃. S.pseudocostatum bloomed just once, in summer, but S.menzelii was isolated in May and again in October. The continuous year-round occurrence of S. costatum s.1. in the bay is supported by the succession of these seven species. Six of the species, except S. menzelii, were important components of algal blooms in the bay. One to four species of Skeletonema were isolated every month. Monthly species diversity was higher when S.ardens, S.costatum s.s., and S.tropicum that are usually associated with tropical or subtropical waters, were isolated. In general, species diversity of the genus Skeletonema was very high in Dokai Bay.