Goniomonas pacifica Larsen and Patterson 1990

Lee, Won Je, 2015, Small Free-Living Heterotrophic Flagellates from Marine Sediments of Gippsland Basin, South-Eastern Australia, Acta Protozoologica 54 (1), pp. 53-76 : 56-57

Goniomonas pacifica Larsen and Patterson 1990 ( Fig. 2c )

Observation: Cells are 4 to 10 µm long with several distinct longitudinal ridges on both sides of the cell. There is a row of about seven to nine ejectisomes near the anterior end of the cell, which is truncated with the posterior end rounded. Two flagella of similar length emerge from a small anterior depression and are directed anteriorly. When the cells are swimming, two flagella diverge in different directions.

Remarks: This species is one of the most widely reported taxa from diverse sites worldwide ( Patterson and Lee 2000). Goniomonas pacifica is similar to a freshwater species ( G. truncata ) in cell shape and having ridges. Also, the length ranges of the two species overlap ( G. pacifica , 4 to 15 µm; G. truncata , 3 to 25 µm). Further study is required to establish the identities of these species. Skvortzov (1932) described Monas abrupta Skvortzov 1932 , which is oval and 7 to 12 µm long, and has ejectisomes near the anterior end of the cell. In the drawings of Skvortzov, two flagella arise from the anterior end of the cell and diverge in different directions. The species is certainly not from the stramenopile genus Monas , and he may have observed a species of Goniomonas . Given the lack of details, ambiguity and absence of appropriate comparisosn in Skvortzov’s descriptions, it is not clear precisely what taxon he observed. The taxon is therefore regarded as a nomen nudum (e.g., Goniomonas abrupta ).

Figures

Fig. 2. a – Chilomastix cuspidata, showing general appearance of cell; b – Goniomonas amphinema, showing general appearance of cell; c – G. pacifica, note two flagella diverging; d – Percolomonas similis, note ventral groove; e – Bodo platyrhynchus; f – Neobodo curvifilus; g – N. saliens; h–i – Hemistasia phaeocysticola, note a papillum (arrow); j – Bordnamonas tropicana, showing general appearance and mouth (arrow); k – Rhynchomonas nasuta; l–o – Rhynchobodo simius; l – tubular ingestion organelle (arrow); m, o – showing groove; n – general appearance of cell; p–q – Rhynchopus amitus; r–s – Spironema multiciliatum; t – Amastigomonas debruynei, general appearance of cell; u – Amastigomonas mutabilis, note anterior flagellum projecting from sleeve and recurrent flagellum; v – Apusomonas sp.; w – Psammosa unguis nov. comb., general appearance of cell; x–y – Mantamonas plastica; x – note anterior flagellum (arrow) and y – ventral depression.All micrographs are DIC images. Scale bar: 5 µm for all figures.