Favoritos de chrisrmoreira

A SEM image of Ditylum brightwellii (T. West) Grunow 1885. Class: Mediophyceae, Subclass: Lithodesmiophycidae, Order: Lithodesmidales, Family: Lithodesmiaceae, Genus: Ditylum. Girdle view, showing rectangular outline. From a culture in f/10 media. A common coastal marine diatom, not reported from polar regions. Cells are generally solitary, however they will form chains; chains are easily broken with agitation. Width: 11-140 µm (Galiano Island observations), 208 µm in culture: personal observations. Rarely accounts for a high percentage of a diatom population (e.g. as an exception it accounted for 95.8% of all diatoms on November 15, 2008 at Spanish Hill Wharf, Galiano Island, British Columbia-MW). A long external process extending from the centre of each valve. Marginal ridge of the valve is often triangular, though other forms, such as square and circular shapes are observed. Chloroplasts are discoid, small and numerous, occurring when not stressed or in a resting state spread out along the outside edge against the cell wall. D. brightwellii and D. sol are the species usually recorded although two more, D. buchanaii and D. pernodii are reported from tropical waters (von Stosch, 1986). Cells orginally collected with a 10 micron net at Spanish Hills Wharf, North Galiano Island (N48˚ 59.688, W123˚ 35.064), Southern Gulf Islands, British Columbia, Canada. SEM image taken with a Hitachi S4800 Scanning Electron Microscope, Advanced Microscope Facility (AMF), University of Victoria.