Goniomonas pacifica 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

Goniomonas pacifica Larsen et Patterson 1990 ( Figs 1m , 2o )

Observation: Cells are truncated with the posterior end rounded. The cells are 4–11 μm long with several distinct longitudinal ridges on both sides of the cell and with a row of ejectisomes near the anterior end of the cell. Two flagella of similar length emerge from a small anterior depression are shorter than the cell and are directed anteriorly, but diverge in different directions when swimming. Commonly observed.

Remarks: This species has been reported from marine sites in Australia, North Atlantic, Brazil, Denmark, England, Gulf of Finland, Hawaii, Panama and Korea ( Larsen and Patterson 1990; Vørs 1992a, b; Patterson et al. 1993; Ekebom et al. 1996; Patterson and Simpson 1996; Tong 1997a; Tong et al. 1998; Lee and Patterson 2000; Lee 2002b, 2006b; Lee et al. 2003) and the previous reported length ranges of G. pacifica are 3 to 15 μm. This species is characterised by the two flagella being directed anteriorly but diverging in different directions when swimming. Goniomonas truncatum and G. pacifica are similar in cell shape and flagella orientation, but can be distinguished because G. truncatum has distinct striations. However, these striations are sometimes difficult to observe, so it may not be a good character. Hill (1991) suggested distinction using length:breadth ratio which is lower in G. pacifica .

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.