Crucigenia mucronata (Smith) Komárek

Kim, Yong Jae, 2017, New records of coccoid green algae in Korea, Journal of Species Research 6 (1), pp. 42-50 : 48

Crucigenia mucronata (Smith) Komárek ( Fig. 4d )

References: Komárek and Fott 1983: 790, pl. 219, fig. 5; Yamagishi and Akiyama 1995: 15:30, figs. 1-5.

Basionym: Crucigenia fenestrata var. mucronata Smith 1926 .

Occurrence site: Chukdong reservoir and fishery (WT 28.3℃, pH 8.3. EC 213 μs/cm).

Description: Free floating cells (4) arranged in coenobia, square to near circular in outline, having small and large square open spaces in the center. Often occurs as multiple coenobia of 16 or more cells. Cells are ellipsoid to square and slightly bent outward, with a small wart-like projection at each end of the outer side. A chloroplast is located in the center of each cell, and contains a pyrenoid. The cells are 5-9 μm in length and 3-6 μm in width.

Distribution: USA (Smith, 1926); France, Guadeloupe, and India ( Komárek and Fott, 1983).

Specimen: NIBRCL0000112297; DAEJIN-20150603-6.

Remark: Smith (1926) did not agree with the description by Schmidle (1900) that there was no gelatinous sheath surrounding the coenobia and filling the central space. He also described differences from the iconotype of the species, reporting cells being ellipsoid to square and slightly bent outward or concave, and lacking projections at the ends of the outer side. This species was originally described as C. fenestrata var. mucronata by Smith (1926). However, Komárek (1974) transferred C. fenestrata var. mucronata to C. mucronata as a basionym. Smith (1926), Komárek and Fott (1983) originally classified this species in the family Scenedesmaceae , order Chlorococcales in the class Chlorophyceae, but Guiry and Guiry (2016) placed in the family Trebouxiophyceae incertae sedi, order Trebouxiophyceae ordo incertae sedi, in the class Trebouxiophycae. Its classifi- cation needs reexamination.

Figures

Fig. 4. a-c. Pachycladella zatoriensis, d. Crucigenia mucronata, e, f. Scenedesmus sempervirens. Scale bar is 10μm.