Protaspa obliqua ( Larsen and Patterson 1990 ) Cavalier-Smith 2011

Lee, Won Je, 2015, Small Free-Living Heterotrophic Flagellates from Marine Sediments of Gippsland Basin, South-Eastern Australia, Acta Protozoologica 54 (1), pp. 53-76 : 63

Protaspa obliqua ( Larsen and Patterson 1990) Cavalier-Smith 2011 ( Fig. 3i )

Observation: Cells are slightly oval or roundish,

13 to 15 µm long, dorso-ventrally flattened and with thickened cortex. There is a ventral median groove; cell indented anteriorly and posteriorly where the groove meets margin. Subapically, the right margin of the groove forms a protrusion. With two flagella inserting under the protrusion; the anterior flagellum is about 0.5 times the cell length and the posterior flagellum is from 0.5 to 1.5 times the cell length. The rounded nucleus does not have nuclear caps, is located subapically in a median position. Commonly observed.

Remarks: Recently, Protaspis Skuja 1939 was replaced with Protaspa by Cavalier-Smith in Howe et al. (2011) because it was preoccupied by the Devonian fish Protaspis Bryant 1933 . This species has been reported from marine sites in Aegean Sea ( Turkey), Australia, England, Fiji and Korea ( Larsen and Patterson 1990; Tong 1997b; Lee and Patterson 2000; Lee 2002b, 2006b; Aydin and Lee 2012) and a freshwater site in Tasmania ( Lee et al. 2005). Cell length was reported to be 8 to 32 µm by previous authors. Generally, the observations are in accordance with those of Lee and Patterson (2000). The protrusion near the flagellar insertions makes this species easy to identify, but Protaspa grandis ( Hoppenrath and Leander 2006) has a protrusion near the flagellar insertion. Protaspa grandis is elongated without the posterior indentation and generally bigger than P. obliqua ( P. grandis , 32.5–55 µm).

Figures

Fig. 3. a–b –Rhynchobodo formica; c –Massisteria marina, general appearance of cell showing pseudopodia and flagella (arrow); d–f – Cercomonas sp.; d – note two acronematic flagella; e – general appearance; f – note flagellar orientation; g–h – Roombia truncata, note cell attached to the substrate by the tip of the posterior flagellum and note extrusomes; i – Protaspa obliqua, note anterior protrusion;j–k – Thaumatomastix setifera, note spines around the body; j – general appearance of cell; k – ventral face showing a deep groove and pseudopodia; l–m – Ancyromonas sigmoides of different cells; l – note slightly thick anterior flagellum with acronematic tip and broad rostrum; m – note thick anterior flagellum and acute rostrum; n–p – Ancyromonas impluvium nov. spec., showing general appearance of cell and note flagellar insertion.All micrographs are DIC images with the exceptions of (d) and (p) which are phase contrast images. Scale bar: 5 µm for all figures.