Anisonema trepidum Larsen, 1987

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 : 495-496

Anisonema trepidum Larsen, 1987

(fi gures 3b, 4h, i)

Description. Cell pro fi le oblong, 13-19 Mm long, 6.5-10 Mm wide, fl attened. With three distinct grooves on the dorsal and ventral faces. Two emergent fl agella are of unequal length. The anterior fl agellum is approximately 1.5 times the cell length, and the trailing posterior fl agellum is stronger than the anterior fl agellum, is approximately 3.5-5 times the cell length and tapers distally. The fl agellar pocket and nucleus are in the left side of the cell. Cells contained small granules. The cells glide quickly and jerk when changing direction. Rarely observed.

Remarks. Cell length was previously reported to be 9-20 Mm and this species was found in marine sites in tropical Australia, Brazil, Danish Wadden Sea, Fiji and Hawaii ( Larsen, 1987; Larsen and Patterson, 1990; Ekebom et al., 1996). Generally, our observations of the appearance of this species agree with those of Larsen and Patterson (1990), but we did not observe the arrests which Larsen and Patterson felt helped to distinguish this species. Anisonema trepidum is distinguished from A. acinus Dujardin, 1841 by its smaller size, cell shape and its behaviour. Anisonema glaciale Larsen and Patterson, 1990 has the same movement as A. trepidium , but can be distinguished by its larger size.