Monosiga brevicollis Ruinen 1938

Aydin, Esra Elif & Lee, Won Je, 2022, Free-living Heterotrophic Flagellates Lakes in Turkey (Protista) from Two Hypersaline, Acta Protozoologica 61, pp. 85-98 : 87

Monosiga brevicollis Ruinen 1938 ( Figs 2o , 3o )

Cells are 4–6 µm long and spherical in the resting state. Swimming cells are more ovoid with a sharpened posterior end and a spread out collar. The collar is about 0.5 times the cell length, while the flagellum is 4–5 times the cell length. The cytoplasm is fine-grained to hyaline and contains strongly retractile grains with a vacuole lying in the posterior part of the cell. Description based on the observations of 16 cells. Occurance: every month with the exception of July and August at Meke Lake, temperature 0–21 °C, salinity 107.5– 215 psu, dissolved oxygen 0.25–5.18 mg /L.

Remarks: As mentioned before by Tong et al. (1997), the species identities of this genus are not clear. Their shapes and lengths may change according to swimming or resting states ( Tong et al. 1997). In general, our observations are in agreement with the original description of Ruinen (1938). Four species, of three by Ruinen (1938) and one by Post et al. (1983), were reported from hypersaline environments: i) Monosiga consociatum Kent, ii) M. ovata Kent, iii) M. brevicollis Ruinen , and iv) Monosiga sp. Monosiga brevicollis differs from M. consociatum with its unique cell shape, short collars and more or less shorter flagellum. The extension of the collar is wider at M. brevicollis compared to M. consociatum . Monosiga brevicollis resembles M. ovata in general cell shape, but the length of flagellum and the collar are quite different. The collar is shorter and the flagellum is longer than that of M. brevicollis’ ( Throndsen 1974). Monosiga brevicollis is reported from Portugal to India (Ruinen 1938), as well as eastern and south-eastern Norway ( Throndsen 1974).

Figures

Fig. 2. (a) Ancyromonas sigmoides, (b) Neobodo curvifilus, (c) Chelonemonas sp., (d) Carpediemonas membranifera, (e) Caecitellus parvulus, (f) Codosiga botrytis, (g) Cafeteria roenbergensis, (h) Pleurostomum flabellatum, (i) Rhynchomonas nasuta, (j) Salpingoeca marina, (k) Pendulomonas adriperis, (l) Neobodo saliens, (m) unidentified protist, (n) Neobodo designis, (o) Monosiga brevicollis, (p) Halocafeteria seosinensis, (q) Cantina marsupialis.

Fig. 3. (a) Ancyromonas sigmoides, (b) Caecitellus parvulus, (c) Cafeteria roenbergensis, (d) Cantina marsupialis, (e) Chelonemonas sp., (f) Codosiga botrytis, (g) Carpediemonas membranifera, (h) Neobodo curvifilus, (i) Neobodo designis, (j) Neobodo saliens, (k) unidentified protist, (l)-(m) Pleurostomum flabellatum, (n) Rhyncomonas nasuta, (o) Monosiga brevicollis, (p) Salpingoeca marina, (q) Pendulomonas adriperis, (r) Halocafeteria seosinensis. All micrographs are DIC images. Scale bar in (k) represents for all figures.