Petalomonas poosilla Larsen et Patterson 1990

Aydin, Esra Elif & Lee, Won Je, 2012, Free-living Heterotrophic Flagellates from Intertidal Sediments of Saros Bay, Aegean Sea (Turkey), Acta Protozoologica 51 (2), pp. 119-137 : 129

Petalomonas poosilla Larsen et Patterson 1990 ( Figs 3d , 4k)

(= Petalomonas pusilla Skuja 1948 )

Observation: Cells are obovate to ellipsoidal, 5–6 μm long and flattened. The single emergent flagellum is shorter than the cell. The reservoir is in the right side of the cell and the nucleus is in the left side. The cells move by gliding. Description based on observations of five cells.

Remarks: This species has been widely reported from marine sites worldwide, with lengths of 4–12 µm ( Lee and Patterson 1998, 2000; Lee et al. 2003; Lee 2006a, 2008, 2012). Lee and Patterson (2000) described two forms of P. poosilla : small cells and large cells differing in shape, size and visibility of ridges. Generally, our observations are in agreement with the small forms, but our cells appear to be different in the cell shape and the position of the flagellar reservoir. Further studies are required to establish if they are one species or if they are different species.

Figures

Fig. 3. a – Petalomonas marginalis; b – Petalomonas minuta; c – Petalomonas ornata; d – Petalomonas poosilla; e–f – Ploeotia corrugata; e – general appearance of the cell from ventral and (f) dorsal view showing the ridges; g – Sphenomonas angusta; h – Ploeotia vitrea; i – Polyoeca dichotoma; j – Protaspis obliqua; k – Protaspis tegere; l – Salpingoeca marina; m – Pseudophyllomitus granulatus; n–p – ‘Aegoni’, n – postero-lateral view of the cell showing the beak – like structure; o – posterior view of the cell showing the flagellar insertions; p – general view of the cell. Scale bar: 5 μm for all figures.