Percolomonas similis Lee et al. 2003

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 : 57

Percolomonas similis Lee et al. 2003 ( Fig. 2d )

Observation: Cells are oval in shape, 5 to 7 µm long, and laterally compressed. Two flagella emerge from the end of a ventral depression. One long flagel- lum is 3 to 3.5 times the cell length, is slightly thinner than the shorter flagellum and is non-acronematic. It is used for adhesion to the substrate and lies underneath the shorter flagellum. The thickened short flagellum is slightly shorter than the cell length, usually lies in the groove and may beat fast in the groove to creat a current of water from which suspended particles are extrated. The cells move by skidding or gliding. Relatively often observed. Description based on records of 20 cells.

Remarks: Percolomonas has been known as having four flagella, but Tong (1997a) included Percolomonas denhami with three flagella and Lee et al. (2003) included Percolomonas similis with two flagella. Percolomonas similis is most similar to P. denhami in cell shape and length, but can be distinguished by the number of flagella and because P. denhami appears to be more flattened laterally. This species can be easily distinguished from the other common species, P. cosmopolitus , because P. cosmopolitus has four flagella: one long flagellum and three short flagella. The short flagella of P. cosmopolitus may be easily overlooked when they beat fast. Further studies are needed to clarify the identities of these three species. The general appearance and moving pattern of the cells are similar to Carpediemonas species, but can be distinguished by the beating pattern of the anterior flagellum which in Carpediemonas , and because the flagella in Percolomonas are directed posteriorly.

Figures

Fig. 2. a – Chilomastix cuspidata, showing general appearance of cell; b – Goniomonas amphinema, showing general appearance of cell; c – G. pacifica, note two flagella diverging; d – Percolomonas similis, note ventral groove; e – Bodo platyrhynchus; f – Neobodo curvifilus; g – N. saliens; h–i – Hemistasia phaeocysticola, note a papillum (arrow); j – Bordnamonas tropicana, showing general appearance and mouth (arrow); k – Rhynchomonas nasuta; l–o – Rhynchobodo simius; l – tubular ingestion organelle (arrow); m, o – showing groove; n – general appearance of cell; p–q – Rhynchopus amitus; r–s – Spironema multiciliatum; t – Amastigomonas debruynei, general appearance of cell; u – Amastigomonas mutabilis, note anterior flagellum projecting from sleeve and recurrent flagellum; v – Apusomonas sp.; w – Psammosa unguis nov. comb., general appearance of cell; x–y – Mantamonas plastica; x – note anterior flagellum (arrow) and y – ventral depression.All micrographs are DIC images. Scale bar: 5 µm for all figures.