Heteronema ovale Kahl 1928

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 : 127

Heteronema ovale Kahl 1928 ( Figs 1r , 2u–v )

Observation: Cell is ovate, dorso-ventrally flattened, and normally about 20 μm long, but is metabolic and can be about 33 μm long when elongated. The pellicular striations follow an S-helix on the ventral and dorsal faces of the cell and may have associated refractile bodies. Two flagella are of almost equal length and are slightly longer than the cell. The posterior flagellum has a knob at its base and is thicker than the anterior one. The ingestion organelle has two rods. The reservoir and nucleus are located in the left side of the cell. The cell moves by skidding or by vigorous squirming in contact with substrate. Description based on observation of one cell.

Remarks: Our observation is generally in agreement with the observations of Lee and Patterson (2000). This species is similar to Heteronema exaratum , but can be distinguished by its more vigorous squirming movements. Furthermore H. exaratum has differences in its dorsal and ventral pellicular striations. These two species are not distinguished by size because there is considerable overlap ( Lee and Patterson 2000). This species was reported from tropical and subtropical Australia, Fiji, Korea, Kuwait and White Sea with a length range of 15–40 μm ( Kahl 1928; Ekebom et al. 1996; Lee and Patterson 2000; Al-Qassab et al. 2002; Lee 2002b, 2006a, 2012; 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.