First records of nine free-living heterotrophic flagellates from South Korea Author Lee, Won Je wonje@kyungnam.ac.kr text Journal of Species Research 2020 9 4 448 454 journal article 10.12651/JSR.2020.9.4.448 2713-8615 13140788 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.