Thecamonas trahens Larsen & Patterson, 1990

Lee, Won Je, 2020, First records of nine free-living heterotrophic flagellates from South Korea, Journal of Species Research 9 (4), pp. 448-454 : 449

2. Thecamonas trahens Larsen & Patterson, 1990

( Fig. 1g -l )

Synonym. Amastigomonas trahens ( Larsen & Patterson, 1990) Molina & Nerad, 1991

Material examined. Korea, Gangwon-do , Gangneung-si, Sachun Beach (37°49′51″N, 128°52′42″E), 21 Oct 2017, collected by Won Je Lee.

Description. Cells are ovate to elliptical and 4.5-7.1 (avg. 5.5) μm long. The proboscis (see Heiss et al., 2015) with a slow to-and-fro motion emerges from the anterior right margin of the cell, and comprises the anterior flagellum surrounded by a membranous sleeve ( Fig. 1i, 1j, 1l , arrowheads). The anterior flagellum is only visible as a dis- tinct structure within the sleeve ( Fig. 1j, 1k ). A posterior flagellum trails under the left margin, and sometimes is long enough to extend beyond the back of the cell ( Fig. 1g-1k ). It moves by a slow, even gliding. The cell body is plastic but not amoeboid, and is deformed during turn- ing. Swimming is not seen. Strands of cytoplasm may be trailed from behind the cell ( Fig. 1h, 1k , arrows). The nucleus is in the anterior left part of the cell. Food vacuoles contain bacteria and detritus.

Previously reported cell length. 4.5-7 μm ( Larsen and Patterson, 1990).

Habitat. Marine intertidal sediments.

World distribution. Australia, Hawaii, Panama, Brazil ( Larsen and Patterson, 1990), Korea.

Deposition. National Institute of Biological Resources, Korea (NIBRPR0000109148).

Identifiers. Won Je Lee.

Figures

Fig. 1. (a)-(f) Notosolenus hemicircularis. (a), (b) cell 1 showing general appearance, (a) note the hyaline semicircular collar (arrowhead), (b) dorsal view showing dorsal ridges, (c)-(e) cell 2 showing a short anterior neck (arrowheads) and dorsal ridges (d), (f) dividing cell. (g)- (l) Thecamonas trahens, showing general appearance, nucleus (N), sleeve (arrowheads) and cytoplasmic strand (St), and note the anterior flagellum (AF). (g) cell 1, (h) cell 2, (i)-(l) cell 3. (m)-(r) Bodomorpha minima, showing general appearance and a rostrum(arrowheads). (m) cell 1, (n) cell 2, (o) cell 3, (p)-(r) cell 4. AF: anterior flagellum, PF: posterior flagellum, FR: flagellar reservoir. All micrographs are DIC images. Scale bar=5 μm for all figures.