J Syst Evol ›› 1992, Vol. 30 ›› Issue (3): 273-276.

• Research Articles • Previous Articles     Next Articles

Minidiscus, a New Recorded Nanodiatom Genus for China

Gao Ya-Hui, Cheng Zhao-Di, Jin De-Xiang (T. G. Chin)   

  • Published:1992-05-18

Abstract: Minidiscus trioculatus, M. comicus and M. chilensis are new records for China, and M. subtilis, is a new species. They differ from Thalassiosira species by their strutted processes and one single labiate process being distant from valve margin and they differ from each other by their areola patterns on valves and distribution patterns of strutted processes and the labiate process. A key to the species of Minidiscus is given. Minidiscus subtilis Gao, Cheng et Chin sp. nov., figs 7-8 Valves disc-shaped, slightly concave in center, weakly silicified, 3.5-5.5μm in diameter. Areola unequally radiate-striate, striae 8.5 / lμm. A narrow valve mantle without striae. Three strutted processes and a single labiate process located in the central area of the valve. Among them, one strutted process in the very center with the other two adjacent to it, forming an isometric triangle with the labiate process between the two subcentral strutted processes. Two small satellite pores in each base of the strutted processes. M. subtilis differs from M. chilensis mainly by their radiate striae continuously distributed from the valve center tothe margin.

Key words: Minidiscus trioculatus, M. comicus, M. chilensis, M. subtilis