Diploneis gemmatula (Grunow) Cleve, 1894

Joh, Gyeongje, 2021, Distribution and frequent occurrence of diatom taxa (Bacillariophyta) inhabiting warmer oceans in Seogwipo coast of Jeju Island, southernmost Korea, Phytotaxa 517 (1), pp. 1-67 : 31

42. Diploneis gemmatula (Grunow) Cleve ( Figs 106, 107 , 211, 212 , 218 )

Basionym: Navicula gemmatula Grunow.

Type locality: not given.

References: Hustedt 1961–1966, p. 527, figs 1038; Witkowski et al. 2000, p. 187, pl. 91, fig. 14.

Morphometrics: Valves 85–120 (50–160) μm long, the width 22.3–31 (23–40) μm in the middle and 28–36 (26–45) μm in the widest portion of the valve, and transapical striae 4–5 (6–7) in 10 μm.

Remarks: Diploneis gemmatula is primarily distributed in the warmer oceans, and in Europe, found only in the Mediterranean (Hustedt 1961–1966, Witkowski et al. 2000). It occurred frequently in the coral reefs of Iraq ( Al-Handal et al. 2018). It is probably a subtropical taxon with a narrow distribution. It was found rarely as benthic diatoms and an epiphyte on seaweeds along the Seogwipo coast in Jeju Island, representing a new record for South Korea.

Figures

FIGURES 101–110. Diatom taxa of Seogwipo coast in Jeju Island (11). Figs 101, 110. Amphora arenaria. Figs 102, 103. Navicula perrhombus. Figs. 104. Cymatoneis circumvallata. Fig. 105. C. margarita. Figs 106, 107. Diploneis gemmatula. Figs 108, 109. D. notabilis. Scale bars = 10 μm.

FIGURES 203–212. Diatom taxa of Seogwipo coast in Jeju Island (21). Figs 203–206. Amphora staurohyalina: external (Figs 203, 204) and internal view (Figs 205, 206) of valves, double striation, hyaline thickened stauros in the middle parts of dorsal side, and apical folds on valve. Figs 207–210. Amphora arenaria: dotted striation and arcing central raphe endings of the external valves (Figs 207–219), internal view of valve (Fig. 210). Figs 211, 212. Diploneis gemmatula: external view of valve. Figs 203–212: SEM. Scale bars = 20 μm (Fig. 211), 10 μm (Figs 207, 210), 5 μm (Figs 203, 206, 209), 2 μm (Figs 204, 205, 208, 212).

FIGURES 213–218. Diatom taxa of Seogwipo coast in Jeju Island (22). Figs 213–215. Amphora cingulata: external view of valve. Figs 216, 217. Campylodiscus brightwellii: external view. Fig. 218. Diploneis gemmatula: internal view. Figs 213–218: SEM. Scale bars = 20 μm (Fig. 218), 10 μm (Figs 213, 216), 5 μm (Fig. 217), 2 μm (Figs 214, 215).