Pachycladella zatoriensis (Bednarz and Mrozinska-Webb) Komárek

Kim, Yong Jae, 2017, New records of coccoid green algae in Korea, Journal of Species Research 6 (1), pp. 42-50 : 47

Pachycladella zatoriensis (Bednarz and Mrozinska-Webb) Komárek ( Fig. 4 a-c)

References: Komárek and Fott 1983: 270, pl. 80, fig. 2; Fučíková 2015: 19-27, fig. 1; Reymond, Yamagishi and Druart 1992: 93-107, figs. 1-27; Reymond, Birchem and Boutinard Rouelle-Rossier 1993: 51-63, figs. 1-6.

Basionym: Pachycladon zatoriensis Bednarz and Mrozinska-Webb 1971 .

Occurrence site: Deokjin reservoir (WT 28.2℃, pH 8.3. EC 101.8 μs/cm).

Description: This species is unicellular and solitary, free floating, and with spherical cell shape and enclosed by a thin wall without a gelatinous envelope. Cell walls bear four long, stout tetrahedral appendages, tapering to blunt or two-forked apices. The base of the appendages situated roughly tetrahedrally. A chloroplast distributed in center of cells, with a pyrenoid. Cells are 7-13 μm in diameter and appendages are 20-50 μm in length.

Distribution: Bangladesh ( Islam and Alfasane, 2005), France ( Reymond et al., 1993), New England ( Fučíková, 2015).

Specimen: NIBRCL0000112296; DAEJIN-20140819-1.

Remark: This species was originally classified as Pachycladon zatoriensis by Bednarz and Mrozinska-Webb (1971), but was transferred to the genus Pachycladella and merged with Pachycladon zatoriensis into Pachycladella zatoriensis as a basionym by Komárek (1979). Reymond et al. (1992) described that this species is very morphologically similar to P. umbrina , but differentiated because the four bifurcated appendages decorating this unicell are located in a cruciate or tetrahedral position. The original description of the genus and its type species Pachycladella umbrina by Smith (1924) is very clear in showing that the cell bears four quadrately (very rarely pyramidally) arranged appendages. This indicates that all species belonging to this genus have appendages arranged in a cruciate position, and rarely tetrahedrally. Reymond et al. (1992) suggested that this is a speciesrather than genus-level feature: only Pachycladella umbrina has appendages in a cruciate disposition, whereas Pachycladon zatoriensis has appendages located tetrahedrally. Reymond et al. (1992; 1993) also showed clearly that these taxa separate into two main categories: cells having appendages located in a cruciate position ( Pachycladella umbrina ), and cells having appendages located in a tetrahedral position ( Pachycladon zatoriensis ). It was also shown that the length of the appendages, and the cell shape and diameter varies markedly among specimens in the same collection, based on transmission electron microscopy ( Reymond et al., 1992; 1993).

Figures

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