Ploeotia pseudanisonema Larsen and Patterson, 1990

Lee, Won Je & Patterson, David J., 2000, Heterotrophic flagellates (Protista) from marine sediments of Botany Bay, Australia, Journal of Natural History 34, pp. 483-562 : 530

Ploeotia pseudanisonema Larsen and Patterson, 1990

(fi gures 17e, 19a, b)

Description. Cell outline oblong or elliptical, about 20 Mm long and 10 Mm wide, fl attened. With several longitudinal narrow grooves extending along the cell. The left half of the cell is thicker than the right half. The anterior fl agellum is about 1.5 times the cell length, and the posterior fl agellum is about 4 times the cell length, emerges as a hook from the fl agellar canal and is stronger than the anterior fl agellum. The posterior fl agellum lies in a ventral groove and tapers towards the tip of the fl agellum. The nucleus is located near the middle of the cell and the reservoir is in the left ventral side. The ingestion organelle is well developed. Cell glides quickly and may jerk backwards—like Anisonema . One cell observed.

Remarks. Larsen and Patterson (1990) fi rst described this species from marine sites in Australia, Brazil, Fiji and Hawaii, and this species has also been reported from other locations in Australia by Ekebom et al. (1996), Patterson and Simpson (1996) and Tong et al. (1998). Previously reported lengths range from 10 to 19 Mm. Generally, our observations agree with the description by Larsen and Patterson (1990). This species is similar to P. longi ®lum Larsen and Patterson, 1990 in having a long trailing fl agellum and in size, but is distinguished by general appearance and one ventral groove in P. longi ®lum. Also, P. pseudanisonema resembles P. punctata Larsen and Patterson, 1990 in general appearance and in having a long posterior fl agellum, but it is distinguished because small internal bodies in P. punctata line the dorsal ridges. Ploeotia pseudanisonem a is similar to Anisonema obliquum Roskin, 1931 and A. trepidum Larsen, 1987 in general appearance and length ( Roskin, 1931; see Larsen, 1987), but is distinguished by the presence of an ingestion organelle.