A Study on the Fine Structure of the Genus Thalassiosira (Bacillariophyceae) in Korean Coastal Waters

Abstract

In order to understand the species diversity of the genus Thalassiosira in Korean coastal waters, Thalassiosira species were collected from October 2007 to December 2008. As a result, a total of 6 Thalassiosira species (T. concaviuscula, T. oceanica, T. partheneia, T. simonsenii, T. nanolineata, and T. sp. nov.) were identified and all species were firstly recorded in Korean coastal waters. We described the distinctive characters of fine structure to identify each species using a Scanning Electron Microscope (SEM); T. concaviuscula has a skirt form of external tubes found on the marginal strutted processes. T. oceanica has the marginal ridges which are interlinked between marginal strutted processes. The valve face of T. partheneia is fairly convex and a labiate process is positioned on the middle between marginal strutted processes. T. simonsenii is characterized by having 2 labiate processes and areolae is somewhat coarse. T. nanolineata has several central strutted process and areolation is linear. Thalassiosira sp. nov. has concave valve face, the marginal strutted processes raised with around basal part and the external form of marginal strutted process looked like barnacle. Most of the species in the present study were nano-sized. The study have to be investigated to understand the speices diversity concerning the diatom using LM and SEM in Korean coastal waters.