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This classification was extensively overhauled by Round, Crawford and Mann in 1990 who treated the diatoms at a higher rank (division, corresponding to phylum in zoological classification), and promoted the major classification units to classes, maintaining the centric diatoms as a single class Coscinodiscophyceae, but splitting the former ...
For many years the diatoms—treated either as a class (Bacillariophyceae) or a phylum (Bacillariophyta)—were divided into just 2 orders, corresponding to the centric and the pennate diatoms (Centrales and Pennales; alternative names Biddulphiales and Bacillariales, as used e.g. in Lee, 1989). [9]
Chaetoceros is a genus of diatoms in the family Chaetocerotaceae, first described by the German naturalist C. G. Ehrenberg in 1844. [1] Species of this genus are mostly found in marine habitats, but a few species exist in freshwater. [2] It is arguably the common and most diverse genus of marine planktonic diatoms, [3] with over 200 accepted ...
Diatoms are eukaryotic organisms in the phylum Bacillariophyta. This page contains articles about diatoms and diatomists.. Older classifications used to subdivide diatoms into Centrales and Pennales (with Bacillariophyceae used as a class), whereas more recent ones use a three classes system: Bacillariophyceae, Coscinodiscophyceae and Fragilariophyceae.
The diatom lineage may go back 180 to 250 million years ago (Mya). About 65 Mya, diatoms survived a mass extinction in which roughly 85% of all species perished. [6] Until 1994, the genus was known as Nitzschia, but was changed to Pseudo-nitzschia because of the ability to form chains of overlapping cells, as well as other minor morphological differences. [8]
These diatoms are photosynthetic organisms, meaning they obtain carbon dioxide from their surrounding environment and produce oxygen along with other byproducts. Reproduce sexually (sexual reproduction is oogamous) and asexually [Guiry 2011]. Skeletonema belong to the morphological category referred to as centric diatoms. These are classified ...
Some pennate diatoms also exhibit a fissure along their longitudinal axis. This is known as a raphe, and is involved in gliding movements made by diatom cells; motile diatoms always possess a raphe. In terms of cell cycle , vegetative cells are diploid and undergo mitosis during normal cell division .
Naviculaceae is a diatom family in the order Naviculales. Naviculaceae are typically composed of lineate areolae, one of the many forms of areolae. Some of the other areolae are punctate (Gomphoneis) and loculate (Diploneis). [1] These can be found among other families of diatoms including Thalassiosiraceae.