Heteronema exaratum Larsen et Patterson 1990

Aydin, Esra Elif & Lee, Won Je, 2012, Free-living Heterotrophic Flagellates from Intertidal Sediments of Saros Bay, Aegean Sea (Turkey), Acta Protozoologica 51 (2), pp. 119-137 : 126

Heteronema exaratum Larsen et Patterson 1990

( Figs 1q , 2p )

Observation: Cell outline ovate, 10–20 μm long, dorso-ventrally flattened, and metabolic, but not vigorously so. The cells have a small ingestion organelle and pellicular striations following an S-helix on both faces of the cell. The dorsal striations are more strongly developed than the ventral ones. Two flagella of similar length are slightly longer than the cell. During movement the anterior flagellum points to the right, and the posterior flagellum to the left. The posterior flagellum has a knob at its base within the flagellar pocket and is thicker than the anterior flagellum. In immotile cells, the flagella coil up. The reservoir and nucleus are in the left side of the cell. The cells move by skidding. Description based on observations of six cells.

Remarks: This species is similar to Heteronema ovale Larsen et Patterson 1990 and H. larseni Lee et Patterson 2000 . It can be distinguished from H. ovale by less vigorous squirming, the more weakly developed pellicular striations and the differences between dorsal and ventral striations and from H. larseni by its weaker pellicular striations and smaller size and by the lack of a posterior point. It has been reported from marine sites in subtropical and tropical Australia, Korea and Fiji with previously reported lengths from 8 to 20 μm ( Larsen and Patterson 1990; Patterson and Simpson 1996; Lee and Patterson 2000; Lee 2002b, 2006a, 2008, 2012; Lee et al. 2003; Tikhonenkov 2006; Al-Yamani and Saburova 2010).

Figures

Fig. 1. a – Actinomonas mirabilis/Pteridomonas danica; b – Amastigomonas mutabilis; c – Ancyromonas micra; d – Bicosoeca conica; e – Bordnamonas tropicana; f – Caecitellus parvulus; g – Cafeteria minuta; h – Cafeteria roenbergensis; i – Cyranomonas australis; j – Developayella elegans; k – Discocelis saleuta; l – Goniomonas amphinema; m – Goniomonas pasifica; n – Kiitoksia ystava; o – Dinema platysomum; p – Anisonema acinus; q – Heteronema exaratum; r – Heteronema ovale; s – Kathablepharis remigera; t – Notosolenus canellatus; u – Massisteria marina; v – Metromonas grandis; w – Neobodo designis; x – Neobodo saliens; y – Percolomonas similis. Scale bar: 10 μm for all figures.

Fig. 2. a – Actinomonas mirabilis/Pteridomonas danica; b – Amastigomonas mutabilis; c – Ancyromonas micra; d – Bicosoeca conica; e – Caecitellus parvulus, note the mouth on the left-hand side; f – Bordnamonas tropicana; g – Cafeteria roenbergensis; h – Cyranomonas australis; i – Developayella elegans; j – Discocelis saleuta; k – Goniomonas amphinema; l – Cafeteria minuta, feeding cell; m – Anisonema acinus, dorsal view, note the ingestion organelle; n – Dinema platysomum, ventral view showing surface striations; o – Goniomonas pacifica; p – Heteronema exaratum, ventral view, general appearance of cell; q – Kathablepharis remigera; r – Massisteria marina; s – Neobodo saliens; t – Neobodo designis; u–v – Heteronema ovale, same cell; u – general appearance; v – extended cell. All micrographs are DIC images. Scale bar: 5 μm for all figures.