Cocconeis cyclophora var. decora A. Schmidt

Joh, Gyeongje, 2021, Distribution of the genus Cocconeis (Bacillariophyceae) along the Seogwipo coast of Jeju Island, South Korea, Phytotaxa 528 (3), pp. 149-179 : 155

7. Cocconeis cyclophora var. decora A. Schmidt ( Fig. 64 )

Basionym: Schmidt et al. 1895, pl. 198, figs 1–3.

References: Wu et al. 2012, p. 771, pl. 1, fig. e; Riaux-Gobin et al. 2017, p. 58, figs 19, 52–54.

Description: Valves elliptical, 33–40 μm long, 20–22 μm wide. SV: sternum sigmoid and enlarged between the middle and ends of the valve. A large ocellus in the middle on one side of valve. Transapical striae coarse and radiate towards the apices, 22–26 in 10 μm, with 17–18 areolae in 10 μm of stria. Three elliptical hyaline areas lacking areolae on each side of the sternum, the hyaline area in the middle connected to the sternum. No RV observed.

Remarks: The variety was reported from the type locality, Yokohama of Japan ( Schmidt et al. 1895). It was found in sediments collected from the 1,071m deep bottom surface of the South China Sea ( Wu et al. 2012), and in marine benthic materials from Nagasaki of Japan through F. Meister’s collections ( Riaux-Gobin et al. 2017). During the survey at Seogwipo coast of Jeju Island, this taxon was encountered twice as epiphytes in small rock pools (St. 2); it is herein newly described for South Korea.

Figures

FIGURES 57–68. LM micrographs of Cocconeis species (4). Figs 57–61. Cocconeis suzukii, RVs (Figs 57, 59) and SVs (Figs 58, 60, 61) (Figs 57 and 58, 59 and 60, complete valves) Figs 62, 63. C. cyclophora var. meisteri, SV. Fig. 64. C. cyclophora var. decora, SV. Figs 65–68. C. voigtii, RVs (Figs 65, 68) and SVs (Figs 66, 67). Scale bar = 10 μm (Figs 57–68).