University of Maine      School of Marine Sciences         ECOHAB-GOM Project 2000


The following are images of Alexandrium sp.  All were taken on a Nikon Optiphot-2 Epifluorescence microscope and CCD camera.  Please do not link this page to any other site.  Also, please obtain permission from Abigail Deitz:  contact or (207) 581-4314, 5741 Libby Hall, University of Maine, Orono, ME 04469-574, before using images outside the ECOHAB-GOM working group.

To reach Sarah Kirn's water column cyst observations, complete with pictures, use this link:  /Web-Pictures/Web-Pictures.htm


St. 67largebreaking20X.bmp (921654 bytes) Image 1. St. 67 (2m) of cruise CH0900 April/May ECOHAB;  large cell approx. 54um theca breaking, note dense, yellow,vacuolar material viewed at 200X magnification.

St.67elong+rxn20X.bmp (921654 bytes) Image 2.  St. 67 (2m)cruise CH0900; elongated/compressed cell with positive reaction to fluoroscein viewed at 200X                                                                                               

St.67largevac+rxn20X.bmp (921654 bytes) Image 3.  St. 67 (2m) CH0900; 53um cell with dense, golden-colored inclusions, with a positive reaction but not strong, 200X                                                                                     

 St.67largevacnegrxn20X.bmp (921654 bytes) Image 4.  St. 67 (2m) CH0900; similar cell to Image 3. but negative reaction to fluoroscein ,200X                                                                                    

St.67nextlargebreaking20X.bmp (921654 bytes) Image 5. St. 67 (2m) CH0900; large cell, 54um, breaking viewed at, 200X                                                                                                                                     

St.67veg20X.bmp (921654 bytes) Image 6. St. 67 (2m)CH0900; vegetative cell approx. 30-32um viewed at 200X, compare to size of larger cells, these are the "normal" cells (in size and morphology)we look for with this staining procedure.

St.45divid 20X.bmp (921654 bytes) Image 7.  St. 45 (2m) CH0900; caught in the act of cell division                           

St. 8 30m 20X large cell.bmp (921654 bytes) Image 8.  St. 8 (30m) collected on cruise END336 first week of April 2000, again a 54um cell full of dense, golden inclusions, note the lack of chlorophyll fluorescence. Is this an heterotrophic A. ostenfeldii?   200X

St. 8 30m 20Xlarge cell breaking.bmp (921654 bytes) Image 9.   St. 8 (30m)  END 336;viewed at 200X one of these large cells is breaking apart. Note that theca breaking away is strongly stained with fluorescence but leaving behind just the red and gold colors of chlorophyll and inclusions....hmmm...would it have looked like Image 4 had the theca separated completely?

St.9 2m 20Xlargereactive cell.bmp (921654 bytes) Image 10a. St. 9 (2m) END 336; 200X; large(54um) reactive cell, low chlorophyll fluorescence

 St.9 2m 20Xlargereactive cell light.bmp (921654 bytes) Image 10b. Same cell in 10a. under tungsten light           


2doublet200xst104.bmp (921654 bytes) Image 11. A duplet from St. 104, June 2000, 2m.   There were a number of duplets in this particular sample and some in surrounding stations as well.  Viewed at 200X.


quadrupchain2m200X.bmp (921654 bytes) Image12.  Chain of four cells seen at St. 23 from the June 2000 cruise.  The occurrence of quadruplet chains in this year's samples has been frequent.


St946tripletchain18u.bmp (921654 bytes) Image 13. Chain of three cells, note gradation in size, larger cell to left, smaller cell on right.  This particular picture is difficult to see with regards to fluorescence due to photobleaching.  Two Ceratium cells are seen to the far left of the chain.


EMphoto1.bmp (180654 bytes) Image 14.   Alexandrium ostenfeldii as seen by electron microscopy.  Sample taken from St. 342 collected on cruise CH09, April/May 2000.  Approximate location at 43 43.51" and 69 54.44". Note shape of primary apical plate with large pore, distinctive of A. ostenfeldii as described by Tomas in Identifying Marine Phytoplankton pg. 496 and 499.

EMphoto4label.bmp (182358 bytes) Image 15. Apical view of both pore complex and first apical plate labelled.


EMphoto2.bmp (62422 bytes) Image 16.   Close up view of this primary apical plate.


EMphoto3.bmp (62422 bytes) Image 17. Close up view of apical pore complex.


.2nonrxostencalc.bmp (921654 bytes) Image 18. Calcofluor stain used to highlight apical plate.   Magnification at 400X.  This cell located in sample from St. 346 of the CH09 April/May 2000 cruise. 


calcofluorlabeled.bmp (921654 bytes) Image 19. Apical view of a calcofluor stained cell.   St. 346 April/May cruise. Apical pore complex (APC) and primary apical plate (1' plate) are labelled.