Aulacoseira (formerly Melosira) granulata is one of the most common diatoms of Lake Kinneret. It is the major phytoplanktonbiomass contributor in winter (Dec -Feb), when the lake is homothermal and it occupies the entire 43 m water column. At the end of the winter bloom in early March the filaments sink and remain in the sediments in a dormant form with compressed chloroplasts till they are resuspended when the lake destratifies the following fall. It is a relatively large filamentous diatom, with cell diameter of 9 -15 um (median: 12.4 um), cell height of 27-37 um (median: 31 um), and mean cell volume of 3700 um 3. The Kinneret Aulacoseira granulata filaments are straight, typically with 8 - 24 cells per filament. The picture shows the typical equal length marginal spines at the perimeter of the end-cell, these are the so-called inking spines which hold adjacent cells together. The chloroplasts fill the entire cells.
aalster and tzohary
A Alster & T Zohary, Kinneret Limnological Laboratory, IOLR
Photo taken with an Olympus BX50 Microscope equipped with DIC optics and PixeLink digital camera, mag. X40