A = Cell with nucleus; B =1'-plate with ventral pore (=arrow); C = Sulcus and part of cingulum; D=Sulcus with fins; E =1' with pore and apical pore complex with pore (comma) and connecting pore (=arrowhead); F=A living cyst (BF) (courtesy of Anna Godhe). A-D = Living cells.(DIC)
Life-form: Solitary or in pairs
Size: Length 25-46 µm.
Resting spore: +
Note: Can be confused with other Alexandrium spp. and Fragilidium spp. Toxic and non toxic strains
Distinctive features: 1'-plate with small ventral pore, apical pore complex
Similar species:
Distribution: Widely
Literature:
Balech, E. & Tangen, K. 1985. Morphology and taxonomy of toxic
species in the Tamarensis group (Dinophyceae): Alexandrium
excavatum (Braarud) comb. nov. and Alexandrium ostenfeldii
(Paulsen) comb. nov. Sarsia. 70: 333-343.
Dale, B.1977b. Cysts of the toxic red-tide dinoflagellate Gonyaulax excavata (Braarud) Balech from Oslofjorden, Norway. Sarsia. 63: 29-34.
Steidinger, K. A. & Tangen, K. 1996. Dinoflagellates. In: Tomas, C. R. (ed.) Identifying marine diatoms and dinoflagellates. Academic Press, Inc., San Diego, p. 387-584.