Fig. 15

Toxigenic dinoflagellate genus Alexandrium. A., B. (SEM), C. (LM) Alexandrium minutum from Port River, Adelaide (SA); B. Cell from Swan River (WA) with areolate ornamentation on hypotheca; D. Diagrammatic summary of ventral view of plate tabulation including details of the apical pore plate Po, the first apical plate 1’ (with ventral pore vp, arrowed) and the anterior sulcal plate Sa; 20 µm wide; E. (SEM), F. (LM), G., H. (SEM) Dinoflagellate Alexandrium australiense from northern Tasmania showing cell shape and details of plate tabulation (G., H.) including the shape of the first apical plate (1’) (with ventral pore, arrowed) and the triangular pore plate Po; 30 µm wide; I. (SEM), J. (plate tabulation) Chain-forming dinoflagellate Alexandrium pacificum from Port Phillip Bay, Melbourne (Vic.), showing short four-celled chains (30 µm wide) of flattened cells, without ventral pore in first apical plate; K., L. (LM) Toxic dinoflagellate bloom of Alexandrium catenella (the east coast of Tasmania).