Sinistermonas sinistrorsus nov. spec., 2015

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 : 68-69

Sinistermonas sinistrorsus nov. spec. ( Figs 1m , 4l )

Diagnosis: Sinistermonas . Cells ovoid, 5 to 8 µm long, rigid, slightly dorso-ventrally flattened. Two flagella of unequal length, beating always to left in small excursion. Move by gliding.

Observation: Cells are ovoid, 5 to 8 µm long, rigid, slightly dorso-ventrally flattened, and with two flagella of unequal length in the same strength. The anterior flagellum emerges sub-apically near the right margin of the cell and directs forwardly to the left direction. It is 1 to 1.5 times the length of the cell and beats always to the left direction in a small excursion. The posterior flagellum emerges near the anterior flagellum and trails behind the cell. It is 2.5 to 3.5 times the length of the cell. The nucleus is located anteriorly. The cells move fast by gliding with the beating of the anterior flagellum. Relatively rare. Description based on observations of five cells.

Remarks: Sinistermonas is similar to Protaspa in being flattened, and having two flagella emerging subapically and anteriorly located nucleus, but it lacks nuclear caps. This species is mostly similar to Protaspa gemmifera , but can be distinguished by its smaller size, and the lack of reserve materials and nuclear caps. It is also different in the position of flagellar insertion. Sinistermonas sinistrorsus is distinguished from Protaspa simplex 1992 because P. simplex lacks the distinguishing characters of Protaspa . It is similar to Cyranomonas australis ( Lee 2002b) in general appearance and cell size, but can be easily distinguished by the flexible body of Cyranomonas and also the position of flagellar insertion. The anterior flagellum of C. australis emerges from the anterior end of the cell, and the posterior flagellum inserts just below the anterior flagellum.

Figures

Fig. 1. a – Chilomastix cuspidata, b – Rhynchopus amitus, c – Spironema multiciliatum, d – Psammosa unguis nov. comb., e – Apusomonas sp., f – Rhynchobodo formica, g – Mantamonas plastica, h – Roombia truncata, i – Thaumatomastix setifera, j – Ancyromonas impluvium nov. spec., k – Helkesimastix faecicola, l – Kurnaimonas celerisnov. spec., m – Sinistermonas sinistrorsus nov. spec., n – Kiitoksia kaloista, o – Protist ‘1’. Scale bar: 10 µm for all figures.

Fig. 4. a – Carpediemonas membranifera; b – Kipferlia bialata; c – Discocelis saleuta, note a short flagellum; d – Metopion fluens, showing general appearance of cell, note shorter flagellum (arrow); e–f – Kurnaimonas celeris nov. spec., showing general appearance of cell; g – Pseudophyllomitus granulatus; h – Helkesimastix faecicola, showing general appearance and note short flagellum (arrow); i – Metromonas grandis, showing general appearance of cell and note the folded margin on the left side and short flagellum (arrow); j – Metromonas simplex, showing general appearance of cell and note short flagellum (arrow); k – Kiitoksia kaloista, showing two flagella and note short flagellum (arrow); l – Sinistermonas sinistrorsus nov. spec., showing general appearance of cell, and note flagellar insertion and beating pattern of anterior flagellum; m – Telonema subtilis, showing general appearance; n – Protist ‘1’. All micrographs are DIC images. Scale bar: 5 µm for all figures.