Pseudo-nitzschia pseudodelicatissima
No picture so far.
Forms stepped chains. Two chloroplasts, one in each end, are seen in the cells. The cells are linear in girdle and valve view. The valves have an eccentric raphe with a central nodule, regularly distributed fibulae and almost twice as many interstriae as fibulae. One row of poroids, and each poroid has two sectors. A cingulum with three bands.
Morphometrics; Apical axis (heteropolar) 54-87 µm, transapical axis 0.9-1.6 µm, 20-25 (28) fibulae and 36-43 interstriae in 10 µm. Poroid density 5-6 in 1 µm. First girdle band with 48-55 poroids in 10 µm.
P. pseudodelicatissima can be confused with species in the pseudodelicatissima complex, like P. cuspidata, P. calliantha, P. cuspidata, P. hasleana etc, all having a valve width<2µm, a central nodule and 1 row of poroids.
Lundholm N, Moestrup Ø, Hasle GR & Hoef-Emden K. 2003. A study of the P. pseudodelicatissima/cuspidata-complex (Bacillariophyceae). What is Pseudo-nitzschia pseudodelicatissima ? Journal of Phycology 39:797-813.
Throndsen J. Hasle G.R. and Tangen K. 2007. Phytoplankton of Norwegian coastal waters. Almater Forlag AS. 341 pp
Globally distributed from tropical to polar waters.